Correlates of fatigue in older adults with chronic heart failure

Although fatigue is a common and troublesome symptom of chronic heart failure (CHF), studies on CHF symptoms have not focused on fatigue. The purpose of this research was to describe fatigue and the relationships among intensity of fatigue, demographic and clinical variables, and functional status in older adults with CHF. The approach to measuring fatigue was based on the fatigue literature in cancer patients, which proposed that fatigue is a self-perceived state and should be measured by self-report. Instruments with established reliability and validity were used to measure fatigue in this descriptive and correlational study: (a) Profile of Mood States (POMS-F), (b) visual analogue scale (VAS-F), (c) functional status (Heart Failure Functional Status Inventory (HFFSI), (d) trait-negative affectivity (Positive and Negative Affect Schedule [PANAS]), (e) symptoms (a symptom checklist), and (f) overall life satisfaction (Satisfaction With Life Scale [SWLS]). Older adults (at least 65 years) with stable CHF and documented systolic dysfunction were enrolled (N = 53). Those with recent changes in their medical regimen, other fatigue-inducing illnesses, and isolated diastolic dysfunction were excluded. The prevalence of fatigue was 96% when measured by the POMS-F and 100% when measured by the VAS-F. The mean POMS-F was 11.5 (SD = 3.8), and the mean VAS-F was 51.8 (SD = 19.3). No significant differences were found in fatigue based on gender. Fatigue (POMS-F) was associated positively and significantly with the New York Heart Association classification, trait-negative affectivity, marital status, perceived health, and symptom severity. In addition, fatigue was associated negatively and significantly with life satisfaction. No relationship was found between fatigue and self-reported activity level. A hierarchical multiple regression model, using six independent variables, explained 50% of the variance of fatigue. Trait-negative affectivity and being married were significant predictors of fatigue. Future studies are needed to describe the patterns of fatigue, determine other correlates of fatigue, and explain how marital status influences fatigue. This study provides background research needed to develop and test interventions aimed at reducing CHF-related fatigue. The findings that fatigue was not related to self-reported activities challenge common assumptions about proxy measures and approaches to clinical assessment.

CORRELATES OF FATIGUE IN OLDER ADULTS WITH CHRONIC HEART FAILURE by Sharon A. Stephen A dissertation submitted to the faculty of The University of Utah in partial fulfillment of the requirements for the degree of Doctor of Philosophy College of Nursing The University of Utah August 2000 Copyright © Sharon A. Stephen 2000 All Rights Reserved THE UNIVERSITY OF UTAH GRADUATE SCHOOL SUPERVISORY COMMITTEE APPRO V AL of a dissertation submitted by Sharon A. Stephen This dissertation has been read by each member of the following supervisory committee and by majority vote has been found to be satisfactory. Chair: Lillian M. Nail Kathleen M. Baldwin Barry J. Cusack ~r?S{cuJL Muriel P. Shaul I t , B. Lee Walker THE UNIVERSITY OF UTAH GRADUATE SCHOOL FINAL READING APPRO V AL To the Graduate Council of the University of Utah: I have read the dissertation of Sharon A. Stephen in its final form and have found that (1) its format, citations, and bibliographic style are consistent and acceptable; (2) its illustrative materials including figures, tables, and charts are in place; and (3) the fInal manuscript is satisfactory to the supervisory committee and is ready for submission to The Graduate School. :4l).1WL I) ;) (J 0 () Date Lillian M. Nail Chair, Supervisory Committee APPro~~a: Linda K. Amos Chair/Dean Approved for the Graduate Council David S. Chapman Dean of The Graduate School ABSTRACT Although fatigue is a common and troublesome symptom of chronic heart failure (CHF), studies on CHF symptoms have not focused on fatigue. The purpose of this research was to describe fatigue and the relationships among intensity of fatigue, demographic and clinical variables, and functional status in older adults with CHF. The approach to measuring fatigue was based on the fatigue literature in cancer patients, which proposed that fatigue is a self-perceived state and should be measured by self-report. Instruments with established reliability and validity were used to measure fatigue in this descriptive and correlational study: (a) Profile of Mood States (POMS-F), (b) visual analogue scale (VAS-F), (c) functional status (Heart Failure Functional Status Inventory (HFFSI), (d) trait-negative affectivity (Positive and Negative Affect Schedule [PANAS]), (e) symptoms (a symptom checklist), and (f) overall life satisfaction (Satisfaction With Life Scale [SWLS]). Older adults (at least 65 years) with stable CHF and documented systolic dysfunction were enrolled eN = 53). Those with recent changes in their medical regimen, other fatigue­inducing illnesses, and isolated diastolic dysfunction were excluded. The prevalence of fatigue was 96% when measured by the POMS-F and 100% when measured by the V AS-F. The mean POMS-F was 11.5 (SD = 3.8), and the mean VAS-F was 51.8 (SD = 19.3). No significant differences were found in fatigue based on gender. Fatigue (POMS-F) was associated positively and significantly with the New York Heart Association classification, trait-negative affectivity, marital status, perceived health, and symptom severity. In addition, fatigue was associated negatively and significantly with life satisfaction. No relationship was found between fatigue and self-reported activity level. A hierarchical multiple regression model, using six independent variables, explained 50% of the variance of fatigue. Trait-negative affectivity and being married were significant predictors of fatigue. Future studies are needed to describe the patterns of fatigue, determine other correlates of fatigue, and explain how marital status influences fatigue. This study provides background research needed to develop and test interventions aimed at reducing CHF-related fatigue. The fmdings that fatigue was not related to self-reported activities challenge common assumptions about proxy measures and approaches to clinical assessment. v TABLE OF CONTENTS Page ABSTRACT o. 0 • 0 • • 0 0 0 • • • • • 0 0 • 0 0 0 • • 0 • • • • • • 0 • • • 0 • • • 0 0 • iv LIST OF TABLES 0" 0 0 0 0 0 •••• 0 0 •••• 0 0 ••• 0 ••• 0 • 0 • 0 0 •••• ix ACKNOWLEDGMENTS ... 0 0 ••••••••• 0 0 0 •••• 0 0 • 0 • 0 •••••• oX Chapter I. INTRODUCTION...... .. 0 • 0 • 0 • 0 • 0 0 • 0 0 0 • 0 • • • 0 0 • 0 0 • • 1 Statement of the Problem . . . . . . . . . . . 0 • • • • • • • 0 • • • 0 • • • • • • 1 Conceptualization of Fatigue . . . . . . . . . . 0 • • • 0 • • • • • • • • • • • 0 • 2 Fatigue and Illness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Fatigue, Aging, and Functional Status ...................... 3 Gender ....................................... 0 .4 Purpose of the Study . . . . . . . . . . . . . . . . . . . . 0 • • • • • • • • • • • .4 Significance to Nursing ........................ 0 • • • • • 0 5 II. BACKGROUND, THEORETICAL FRAMEWORK, AND CONCEPTUAL MODEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Introduction ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 Background ........... 0 • • • • • • • • • • • • • • • • • • • • • • 0 • • .6 Fatigue .................................... 06 Cardiovascular Fatigue . . . . . . . . . . . . . . . . . . . . . . . 0 • • 0 9 Chronic Heart Failure and the Elderly . . . . . . . . . 0 • • 0 0 0 • 0 10 Critique of Relevant Research 0 0 • • • 0 • 0 0 0 • 0 • 0 • • • 0 0 • 0 • • 0 • • 12 Chronic Heart Failure-Related Fatigue ............ 0 ••• 12 Summary of Limitations and Gaps in Current Research 0 0 •• 0 • 0 •• 0 0 21 Factors Associated with Chronic Heart Failure-Related Fatigue ...... 22 Age 0 ••• 0 • 0 ••••• 0 0 ••••••• 0 •• 0 ••••••• 0 ••• 0 022 Gender 0 ••••• 0 •••• 0 ••••••• 0 •• 0 0 •••••• 0 •••• 023 Comorbidity ... 0 • • 0 0 0 • 0 0 0 • • 0 • • • • 0 • 0 • • • 0 0 • 0 • 0 24 Deconditioning . . . . . 0 0 • • 0 • 0 • • • • • • • • • • 0 • • • • • 0 0 • 25 Sleep Disturbances 0 •••••••••••••••••• 0 •• 0 0 •• 0 0 26 Pain .......... 0 ••• 0 • 0 0 ••••• 0 ••• 0 • 0 •• 0 •• 0 027 Chapter Page Mood Disturbances ............................ 27 Medications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 NUITlber of Symptoms . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Atrial Fibrillation ............................. 29 Operational Defmitions .............................. 30 Fatigue .................................... 30 Disruption of Lifestyle .......................... 31 Self-Perceived Functional Status .................... 31 Chronic Heart Failure .......................... 31 Left Ventricular Systolic Dysfunction . . . . . . . . . . . . . . . . . 31 Older Adult . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Severity of Illness ............................ 32 Quality of Life ............................... 33 Purpose and Research Questions . . . . . . . . . . . . . . . . . . . . . . . . . 34 Theoretical Framework .............................. 35 III. METHODS ..................................... 41 Design ........................................ 41 Sample ........................................ 42 Setting ........................................ 44 Description of the Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Demographic Questionnaire .... . . . . . . . . . . . . . . . . . . . 45 Clinical Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Profile of Mood States-Short Form . . . . . . . . . . . . . . . . . . . 46 Visual Analogue Scale for Fatigue ................... 47 Heart Failure Functional Status Inventory . . . . . . . . . . . . . . . 49 Minnesota Living with Heart Failure Questionnaire ......... 50 Positive and Negative Affect Schedule ................ 51 Satisfaction With Life Scale . . . . . . . . . . . . . . . . . . . . . . . 52 Symptom Checklist (Heart Version) .................. 52 Procedures for Data Collection ......................... 53 Geriatric Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Human Subjects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Procedures for Data Analysis .......................... 59 Preliminary Analysis ........................... 59 Missing Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 Descriptive Analysis ........................... 60 Testing Assumptions of Multiple Regression . . . . . . . . . . . . . 63 vii Chapter Page IV. RESULTS ...................................... 64 Sample ........................................ 64 Demographic Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Clinical Data .................................... 67 Environmental Variables ............................. 70 Research Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 V. DISCUSSION.................................... 87 Prevalence and Intensity of Fatigue . . . . . . . . . . . . . . . . . . . . . . . 87 Fatigue and Functional Status .......................... 90 Predictors of Fatigue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Measurement Issues ................................ 95 Strengths and Limitations of the Study . . . . . . . . . . . . . . . . . . . . . 97 Strengths .................................. 97 Limitations ................................. 98 Recommendations for Future Research . . . . . . . . . . . . . . . . . . . . 100 Nursing Implications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Summary Statement ............................... 104 Appendices A. DEMOGRAPHIC QUESTIONNAIRE 106 B. CLINICAL INFORMATION FORM ..................... 110 C. VISUAL ANALOGUE SCALES ....................... 113 D. HEART FAILURE FUNCTIONAL STATUS INVENTORY ...... 115 E. SYMPTOM CHECKLIST (HEART VERSION) .............. 120 F. INFORMED CONSENT ............................ 126 REFERENCES ...................................... 130 viii LIST OF TABLES Table Page 1. Summary of Sample Characteristics . . . . . . . . . . . . . . . . . . . . . . . 66 2. Summary of Clinical Variables . . . . . . . . . . . . . . . . . . . . . . . . . . 68 3. Adherence to Prescribed Treatments and Medications for Chronic Heart Failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 4. Pearson Product-Moment Correlation Coefficients Between Fatigue Measures and Selected Variables ......... . ...... 73 5. Point Biserial Correlation Coefficients Between Fatigue Measures and Selected Categorical Variables . . . . . . . . . . . . . . . . . 74 6. Measures of Central Tendency for Fatigue and Vigor by Gender ..... 76 7. Means, Standard Deviations, and Ranges of Scored Instruments ..... 78 8. Summary of Hierarchical Multiple Regression Analysis With the Dependent Variable, Fatigue (Profile of Mood States) ......... 84 9. Summary of Backward Multiple Regression Analysis Predicting Chronic Heart Failure-Related Fatigue in Older Adults ........... 86 ACKNOWLEDGMENTS I wish to thank my committee for their mentoring, expertise, and commitment to this research: Lillian Nail (chair), Lee Walker, Muriel Shaul, Barry Cusack, and Kathy Baldwin. I am grateful for an excellent graduate education and owe this to the talents of the faculty at the College of Nursing. Thanks in particular to Marge Pett who taught me statistics! The staff and advisors at the college deserve special mention for being so helpful and friendly to this long­distance student. I am indebted to the financial support I received along the way: T-32 Predoctoral Fellowship, teaching and research assistant work opportunities, and the Margaret Olwell Scholarship. In addition, I want to credit my father for not only giving me his love of learning but also being willing to help me financially with my education. Thank you to the faculty and students in nursing at Boise State University who inspired me to pursue this goal. I would like to recognize the many friends, relatives, neighbors, and colleagues who cheered me on. Special gratitude is extended to my classmate, Sandy Smith, who was always a true friend. This work could not have been completed without the patients who live with chronic heart failure (CHF) and their nurses and doctors. I am especially appreciative of the staff at Treasure Valley Cardiology in Boise, along with Dr. Graham Wetherley, Dr. Peter Roan, and Jill Anderson, for their support. Finally, I want to thank my family (Stu, Kim, and Makenzie) for joining me in this ad venture and for making many sacrifices. I dedicate this effort to my family because they made it possible. xi CHAPTER I INTRODUCTION Statement of the Problem The syndrome of chronic heart failure (CHF), frequently referred to as congestive heart failure, is serious, progressive, and epidemic in older Americans. Mortality and morbidity from CHF continue to be high in spite of advances in medical treatment. Fatigue, a common and often disabling symptom in older adults with CHF, has not been the focus of research. Studies are needed to describe both fatigue and the impact of fatigue on daily activities in older adults with CHF. Nurses need knowledge about CHF-related fatigue and the consequences of this symptom for their patients. This knowledge is important to the development of interventions aimed at preventing and reducing fatigue. The study was guided by the conceptual model of symptom management that views synlptonls as the primary focus based on the assumption that symptoms cause distress (University of California, San Francisco, 1994). The model displays an interaction between symptom experience, symptom management strategies, and symptom outcomes. The symptom experience consists of the interplay between the perception of symptoms, the evaluation of symptoms, and the response to symptoms. The common-sense model provided the theoretical foundation for the research (Leventhal, Nerenz, & Steele, 1984). According to Leventhal and colleagues, individuals are motivated to understand their symptoms, and their personal representation of their symptoms is what drives subsequent actions taken to cope with these symptoms in an effort to reduce health threats. Conceptualization of Fatigue Based on concept analysis, fatigue is defined as "a subjective, unpleasant symptom which incorporates total body feelings ranging from tiredness to exhaustion creating an unrelenting overall condition which interferes with individuals' ability to function to their normal capacity" (Ream & Richardson, 1996, p. 527). Nursing interventions prescribed for fatigue are frequently focused on restoring the activity and rest balance (Bousquet, 1990). 2 The mechanisms underlying fatigue are not well-understood but probably involve an interaction among physical, psychological, behavioral, and situational factors (Gift & Pugh, 1993). In the absence of knowledge of the etiology of fatigue, an exploration of fatigue and the factors associated with it will advance the knowledge base and assist researchers interested in developing interventions to mitigate fatigue. In this study, fatigue was conceptualized as a subjective, multidimensional phenomenon and was measured as a self-perceived sensation. Fatigue and Illness Fatigue is universal in both health and illness. In chronic illness, fatigue is ubiquitous, having been described in cancer, rheumatoid arthritis, fibromyalgia, renal disease, multiple sclerosis, ankylosing spondylitis, lupus, and acquired 3 immune deficiency syndrome (AIDS) (Belza, Henke, Yelin, Epstein, & Gilliss, 1993; Brunier & Graydon, 1993; Calin, Edmunds, & Kennedy, 1993; Darko, McCutchan, Kripke, Gillin, & Golshan, 1992; Hart, 1978; Krupp, LaRocca, Muir, & Steinberg, 1990; McCorkle & Quint-Benoliel, 1983; Silverman, Belza, Mason, & Nakasone, 1993; Wolfe, Hawley, & Wilson, 1996). The greatest research efforts have occurred in cancer-related fatigue. Several reviews of the cancer­related fatigue literature have been published (Richardson, 1995; Smets, Garssen, Schuster-Uitterhoeve, & deHaes, 1993). A state of the science paper summarizes what is known about cancer-related fatigue and recomnlends directions for future research (Winningham et al., 1994). In addition to association with chronic illness, fatigue has been described as a lingering symptom that occurs following surgery, specifically cardiac surgery (Gregersen, 1993; Pick, Molloy, Hinds, Pearce, & Salmon, 1994). Fatigue also occurs with stressful events such as environmental demands, childbirth, and care-giving burden (Jensen & Given, 1991; Lee, Lentz, Taylor, Mitchell, & Woods, 1994; Pugh, 1993). Attentional fatigue, a decreased ability to concentrate, has been described following breast cancer surgery (Cimprich, 1992). Fatigue. Aging, and Functional Status Aging is associated with a decrease in energy and vitality (Mitchell, 1986). Illness-related fatigue such as the fatigue that occurs with CHF may be attributed to aging. Older adults may not report symptoms of fatigue to health care providers if they interpret their fatigue as merely a symptom of aging. Moreover, aging may 4 place individuals at high risk for negative consequences of fatigue if adaptation leads to self-imposed restrictions in daily activities. Fatigue may lead to the inability of perfomling ordinary activities required for daily living that compromise independence. Functional status is a broad construct that includes activities of daily living and is a common indicator of health status in older adults. Ware and Sherbourne (1992) described the domains of functional status as physical, role, and social functioning; pain; general mental health; vitality; and general health perceptions. In this study, self-perceived functional status was an outcome measure defined as the self-report of the capacity to perform daily activities. The symptoms that limit functional status, with a focus on fatigue, were described. Gender Fatigue predominates in women in the general population, with 20 % of women reporting fatigue compared to 14% of men (Chen, 1986). The gender differences in fatigue for individuals with CHF have not been described. Many of the studies on CHF and symptoms have included only men or a small percentage of women. Since CHF is common in both older men and women, it is important to determine whether or not there are differences in fatigue based on gender. Purpose of the Study The purpose of this study was to describe fatigue and the relationships among intensity of fatigue, demographic and clinical variables, and functional status in older adults with CHF. The study was designed to answer the following three research questions: 5 1. What are the prevalence and intensity of fatigue in older men and women with CHF secondary to left ventricular systolic dysfunction? 2. What is the relationship of fatigue to self-perceived functional status in older men and women with CHF secondary to left ventricular systolic dysfunction? 3. When controlling the severity of illness, what combinations of clinical and demographic variables explain fatigue in older men and women with CHF secondary to left ventricular systolic dysfunction? Significance to Nursing Research focused on fatigue is important to nurses because it is a common concern of patients. CHF-related fatigue is a distressing symptom that interferes with the ability to perform ordinary activities required for independent daily living. Fatigue also can prevent people from adhering to prescribed exercises that lead to deconditioning and further fatigue. The negative impact of fatigue on functional status in the elderly can result in the loss of independence, mood disturbances, and dissatisfaction with life. A priority for cardiovascular nurses is to improve the quality of life in their patients. By becoming better informed about the symptoms of CHF, nurses can strengthen their assessment skills and plan appropriate and efficacious interventions for fatigue. The rising prevalence of CHF, especially in the elderly, lends further importance to this endeavor. CHAPTER II BACKGROUND, THEORETICAL FRAMEWORK, AND CONCEPTUAL MODEL Introduction This chapter reviews the literature on fatigue associated with CHF and identifies the gaps in existing research. Background supporting this inquiry is provided through discussion of the phenomenon of fatigue, cardiovascular fatigue, and an overview of CHF. The research on factors that may be associated with fatigue in CHF is reviewed to inform the selection of variables to study. Last, the conceptual framework that guided and organized this investigation is described. Background Fatigue Fatigue is a universal sensation that occurs in health and illness. In health, fatigue may serve as a warning of energy depletion or follow vigorous activity. ' In ibis context, fatigue is predictably relieved with rest and is believed to be normal ' and essential (Hart, Freel, & Milde, 1990). Potempa (1993) referred to this fatigue as normative. The fatigue of illness is prevalent and nonspecific, and may possess an intensity that ranges from mild to exhaustion (Potempa, 1993). Fatigue associated 7 with illness has been classified as acute and chronic (Piper, 1989). Acute fatigue presents and subsides suddenly and is frequently severe, forcing those afflicted to retreat and rest. Chronic fatigue is often more subtle and vague, long-lasting by definition, and less predictable in its pattern (Potempa, 1993). Chronic fatigue is associated with many chronic illnesses. Anecdotal reports from patients with CHF describe the "good day, bad day" pattern of fatigue. Comprehensive reviews of the literature on chronic fatigue help to summarize the current understanding (Hart et aI., 1990; Piper, 1989; Potempa, 1993). Fatigue is a complex phenomenon that has been described as a symptom, diagnosis, side effect of treatment, and syndrome (Tiesinga, Dassen, & Halfens, 1996). The present study was concerned about fatigue as a symptom in relationship to CHF. Defining fatigue has been troublesome, and the lack of consensus in the conceptualization of fatigue has been an impediment to research of this phenomenon (Winningham et aI., 1994). Fatigue is the perception of a sensation that is unpleasant and has negative consequences on behavior and mood. "Fatigue is a subjective self-evaluation of sensations associated with discomfort, decrease in motor and mental skill, and increased task difficulty" (Hart et al., 1990, p. 976). However, fatigue is not weakness that is defined as "a decrement in muscle strength or endurance compared with some baseline level" (Nail & Winningham, 1995). Fatigue has been described as weariness or tiredness (Gift & Pugh, 1993). In this study, the recent definition of fatigue proposed by Ream and Richardson (1996) following extensive review of the fatigue literature and concept analysis was used. These authors proposed the following: "Fatigue is a subjective, unpleasant symptom which incorporates total body feelings ranging from tiredness to exhaustion creating an unrelenting overall condition which interferes with individuals' ability to function to their normal capacity" (Ream & Richardson, 1996, p. 527). The mechanisms underlying fatigue are poorly understood. Nail and Winningham (1995) concluded that the mechanism explaining fatigue involves "a complex feedback-regulated interplay of physiological, psychological, and situational factors" (p. 273). Potempa (1993) hypothesized the presence of a common mechanism to explain the similarity of fatigue across many different clinical contexts. 8 Fatigue affects physical, emotional, social, role, and cognitive functioning (Piper, 1989). Simply stated, fatigue reduces the quality of life. More specifically, fatigue interferes with the performance of activities of daily living, causing tasks to be completed at a slower speed than usual and generating a need for rest periods (Mayou, Blackwood, Bryant, & Garnhanl, 1991). Fatigue results in a reduced ability to complete tasks, and it may lead to mood disturbances, dependency on others, and decreased mobility contributing to skeletal muscle atrophy. In addition, fatigue may decrease ambition, motivation, and spontaneity, resulting in failure to adhere to a regular exercise program. Cardiovascular Fatigue Few descriptive studies have examined fatigue in cardiac patients as the primary aim (Friedman & King, 1995; Pick et al., 1994; Schaefer & Potylycki, 1993). Fatigue has been found to be a common symptom that occurs during recovery from a cardiac event and was reported as an incidental finding in several studies (Dracup, Walden, Stevenson, & Brecht, 1992; Gortner et al., 1988; King, 1985; King & Parrinello, 1988; Vogt, Funk, & Remetz, 1994). Correlates of fatigue have been described in older women with CHF (Friedman & King, 1995). Only one study has examined the impact of symptoms on functional status in cardiovascular patients (Mayou et al., 1991). 9 The lack of reliable and valid instruments to measure fatigue in cardiovascular patients has hindered the research process. Typically, fatigue has been measured using a single item or a single item embedded in a symptom checklist. The Profile of Mood States (POMS) has been used frequently in cardiac patient samples to measure mood disturbances but not fatigue. Gregersen (1993) introduced a multiitem scale to measure fatigue following cardiac surgery; however, no subsequent research has provided evidence for reliability and validity. Guyatt and colleagues (1989) crafted the Chronic Heart Failure Questionnaire. Although the primary focus of this tool is the impact of dyspnea on important daily activities, fatigue is also measured. Fatigue is a common problem in both the medical and surgical management of cardiovascular patients. Fatigue is a leading symptom, second only to angina, in 10 persons recovering from a cardiovascular event (Vogt et aI., 1994). These investigators found that following cardiovascular medical interventions fatigue does not subside like other symptoms such as angina and shortness of breath. Angina has been the symptom that has received nluch research attention. Nurses have long recognized the problem of fatigue and the negative impact on quality of life for patients with CHF. With the exception of the work of Friedman and King (1995), Gregersen (1993), Pick and colleagues (1994), and Schaefer and Potylycki (1993), fatigue has not been the focus of study in cardiovascular patients. Chronic Heart Failure and the Elderly An estimated 400,000 new cases of CHF are reported each year, and the prevalence is rising, especially for individuals 65 years and older (Konstam et aI., 1994). Other cardiovascular diseases such as stroke and myocardial infarction are declining; however, CHF is escalating and is estimated to affect 4.6 million Americans (American Heart Association, 1999). The mortality rate is nearly 80% in men and 65 % in women at 6 years from diagnosis (Guidelines, 1995). Patients refer to CHF as having "cancer of the heart." CHF is the most frequent cause of hospitalization in the elderly and is estimated to cost $10 billion each year to treat (Konstam et al., 1994). As the population ages, the prevalence of CHF is expected to rise substantially, causing a strain on health care resources (Rich, 1997). The most common causes of CHF are ischemic heart disease, hypertension, aortic stenosis, and idiopathic-dilated cardiomyopathy (Dracup, 1996; Guidelines, 1995). CHF is a clinical diagnosis based on common symptoms of exertional 11 dyspnea, fatigue, edema, and weight gain (Consensus, 1999). The elderly may present with few of the classic symptoms and more nonspecific complaints such as fatigue, anorexia, generalized weakness, dry cough, and mental disturbances (Tresch, 1997). The evaluation of left ventricular function is advised for all patients newly diagnosed with CHF (Guidelines, 1995; Konstam et aI., 1994). This assessment is necessary to differentiate between systolic and diastolic left ventricular dysfunction. CHF with diastolic dysfunction and preserved systolic function is more common in the elderly than CHF due to systolic dysfunction, but there is less certainty in the diagnosis of CHF with diastolic ventricular dysfunction (Tresch, 1997). Moreover, the recent practice guidelines have focused on patients with systolic dysfunction because less is known about CHF secondary to diastolic dysfunction (Guidelines, 1995; Konstam et aI., 1994). The most common method used to assess left ventricular ejection fraction (L VEF) is transthoracic Doppler two-dimensional echocardiography. Systolic dysfunction is confrrmed with a L VEF of 35 % to 40 % or lower (Konstam et al., 1994). LVEF is calculated by dividing the difference between end-diastolic volume and end-systolic volume by end-diastolic volume. The calculations of LVEF can be obtained from radionuc1ide ventriculography, cardiac catheterization with left ventricular ventriculography, and echo cardiography (Konstam et al., 1994). CHF is medically managed with medications, a salt-restricted diet, and a balance between adequate rest and regular exercise. The new guidelines recommend all patients with stable CHF, except those categorized as the New York Heart Association (NYHA) class IV (symptomatic at rest), be counseled to maintain a regular aerobic exercise program (Consensus, 1999; Konstam et al., 1994). Dracup (1996) recommended that patients be taught to perform regular walking or bicycling and to stop exercise only if their fatigue is excessive. It follows that if patients attempt to avoid fatigue entirely, they nlay not be able to follow their prescribed exercise. Critique of Relevant Research Chronic Heart Failure-Related Fatigue 12 Only three studies were found that systematically examined fatigue in CHF (Friedman & King, 1995; Mayou et al., 1991; Schaefer & Potylycki, 1993). Several other studies directly related to the present research address symptoms, daily physical activity, and functional status in CHF (Dracup et al., 1992; Fontana, 1996; Hawthorne & Hixon, 1994; Oka, Stotts, Dae, Haskell, & Gortner, 1993). Fatigue is a widely recognized problem for persons with CHF, and the absence of research focused on this problematic symptom is surprising. Related studies documented that fatigue is common in the cardiovascular population and a distressing symptom for persons with CHF. These studies were reviewed prior to the critical appraisal of the research on fatigue, functional status, and CHF. Fatigue in cardiac patients was initially conceptualized as an emotional response or mood disturbance (Denollet, 1993; King, 1985). The popularity of the POMS may explain this tendency since one of the subscales is fatigue. In patients 13 undergoing coronary artery bypass grafting, King (1985) reported high fatigue and low vigor in the imnlediate postoperative period. By discharge, fatigue and vigor were returning to baseline levels; however, fatigue remained elevated above baseline 3 weeks following hospital discharge. Fatigue was not associated with cardiorespiratory fitness but was found to be a correlate to negative affectivity in men with coronary heart disease (Denollet, 1993). Neither of these studies identified subjects as having CHF. Pick and colleagues (1994) designed a descriptive, correlational study to explore relationships between fatigue and neuroendocrine response to surgery in 74 patients undergoing coronary artery bypass surgery. In addition, a relaxation intervention was tested using postoperative fatigue as an outcome measure. Patterns of postoperative fatigue were described demonstrating the expected time-dependent decline in fatigue. Fatigue levels at 30 days following surgery were found to correlate positively with perioperative noradrenaline levels (r = .23 to .46, 12 = .05) (Pick et al., 1994). The relaxation intervention had no effect on postoperative fatigue. The researchers concluded that fatigue has both physiological and emotional dimensions and that the effect size of the intervention may have been too small to detect. Physical fatigue and mental fatigue were measured using a single­item, 3-point scale and asking subjects to evaluate their fatigue compared to preoperative recall of fatigue. No psychometric infonnation was provided on the scale, and no mention was made of pretesting the scale in their sample. Fatigue that occurs in chronic illnesses such as CHF may not be the same phenomenon as postoperative fatigue. In the mid-1980s, a movement in cardiovascular research demanded the inclusion of quality-of-life outcomes in clinical trials for CHF. Researchers involved in CHF drug trials began to focus on symptoms and functional status as clinical outcomes to demonstrate therapeutic benefit rather than survival outcomes (Feinstein, Fisher, & Pigeon, 1989). This paradigm shift caused controversy and confusion about what variables measured quality of life. An added challenge was that there were few valid and reliable health-related quality-of-life instruments suitable for individuals with CHF available to researchers. 14 The development of instruments to measure quality-of-life outcomes in randomized, placebo-controlled heart failure trials focused on the relief of symptoms. Fatigue was identified as one of the symptoms amenable to treatment. While researchers did not focus on fatigue, the data presented in their papers and discussions about symptoms showed fatigue to be a significant problem for persons with CHF (Feinstein et aI., 1989; Guyatt et aI., 1989; Rector & Cohn, 1992; Tandon, Stander, & Schwarz, 1989). Early efforts to design an instrument sensitive to changes produced by therapeutic interventions led to a clinical index of dyspnea and fatigue (Feinstein et al., 1989). This index was modified from the Yale Scale and was similar to the NYHA classification but improved upon it by providing 12 possible levels rather than 4. The index is clinician rated based on history data obtained from interviews and was tested in a sample of 362 patients with CHF during a multisite, 15 randomized trial comparing the effects of lisinopril with captopril. Reliability was not discussed; however, validity was supported with a low positive but significant correlation (r = .44, n < .0001) to a global rating of improvement by the patient. The index has been criticized because subjective symptoms are assessed using clinician ratings (Rector & Cohn, 1992). The Patient's Self-Rating Scale was used to measure nine symptoms on a 0 to 10 scale in which 0 designates no nroblem and 10 designates severe nroblem (Tandon et al., 1989). Fatigue/tired/lack of energy was rated as the symptom causing the greatest problem at baseline for the standard therapy and placebo groups with a mean of 5.0 and 4.8, respectively. The next highest symptom was shortness of breath with a mean of 3.8 in the standard therapy group and a mean of 3.57 in the placebo group. Sleeplessness was the third highest. The other six symptoms were all rated as less than two in both groups. While not focused on fatigue, this study demonstrated that fatigue is a primary symptom in CHF and is problematic for those afflicted. In preliminary work to select items for the Chronic Heart Failure Questionnaire, four out of six of the fatigue items received the highest scores (Guyatt et al., 1989). The Chronic Heart Failure Questionnaire was created based on the most frequently selected and important items and consists of 16 items that measure fatigue, dyspnea, and emotional dysfunction. The five dyspnea items are based on quantifying shortness of breath during five highly valued activities individualized for each subject. Fatigue is measured as the total score based on 16 four items. Fatigue was found to be the most common and significant problem, yet efforts were made to individualize the valued activities associated with dyspnea. The Minnesota Living with Heart Failure (LIhFE) questionnaire was developed to provide a valid, reliable, and sensitive outcome measure for clinical trials in CHF (Rector & Cohn, 1992). The questionnaire is a 21-item self­assessment scale using a 0 to 5 scale, with 0 indicating no, 1 very little, and 5 yg:y much. One item asks, "Did your heart failure prevent you from living as you wanted during the last month by: making you tired, fatigued, or low on energy?" This item is grouped in the physical dimension that includes seven other items. The scale contains two primary dimensions: (a) physical and (b) emotional. Several of the items did not fit in either of the dimensions and were placed in a third and fourth dimension consisting of dissimilar items. Content validity was demonstrated with comparisons to global rating of changes in dyspnea and fatigue. Rector and Cohn commented, "Limitations as a result of fatigue and shortness of breath are a primary concern of patients with heart failure" (p. 1021). However, the LIhFE measures fatigue as a single item within a scale, and scoring does not allow the isolation of fatigue (Rector & Cohn, 1992). The LIhFE has strong test-retest and internal consistency reliability. Validity was supported with improved scores in the treatment group but not the placebo group. Scores on the LIhFE were not correlated to L VEF. The work of Rector and Cohn (1992) in instrument development has advanced what is known about fatigue in heart failure. Fatigue is a common, distressing symptom in CHF and limits physical functioning. Unfortunately, none of the instruments developed for individuals with CHF is judged suitable for the measurement of fatigue. The LlhFE shows promise for describing the impact of symptoms on daily activities and lifestyle. 17 Mayou and colleagues (1991) described the symptoms of CHF and the associations between exercise capacity and aspects of quality of life. The sample consisted of men and women (n = 123), average age of 60, most of whom had NYHA class II CHF. People in NYHA class II reported dyspnea with ordinary activities. Fatigue was measured along with other symptoms of CHF on a 5-point Likert scale rated by the clinician based on interview data. Mayou and colleagues (1991) found that fatigue was a common symptom in patients with CHF and that it was associated with other physical symptoms such as breathlessness, chest pain, difficulty sleeping, and palpitations. Fatigue was experienced at least "some of the time" by 70% of the sample. Mood disturbance was measured using the 41-item version of the POMS, with high levels of fatigue (.M = 7.4) and lack of vigor (M = 12.4) found. Limitations of this study were the use of clinician-rated symptom items and the lack of a comparison group. An important finding was that fatigue, combined with other symptoms of CHF, limited physical activities, particularly the speed with which activities are performed (Mayou et al., 1991). Symptoms of CHF interfered with the ability to exercise. Subjects reported that they completed the same amount of tasks in a day but did so slowly. They also reported that physical activities were associated with 18 worry, frustration, and discomfort. Subjects who performed poorly during treadmill testing of exercise capacity were more likely than subjects who performed well to be rated as having greater fatigue. They also reported a slow walking pace, performing ordinary daily tasks slowly, and having more sleep disturbances. An implication from this research is the importance of measuring the decreased speed of walking pace and performance of physical activities when studying the impact of fatigue on functional status. The Heart Failure Functional Status Inventory (HFFSI), selected for this study, captures activities that are performed at a slower than normal rate (Dracup et al., 1992). Schaefer (1990) and Schaefer and Potylycki (1993) reported data from different stages of a single study. Schaefer and Potylycki also reported that 71 % of patients complained of fatigue on admission to the hospital with CHF. The severity of fatigue at the time of interview during hospitalization had decreased compared to admission fatigue based on recall. Age was the only variable examined that was significantly associated with severity of fatigue (r = .39, I! < .01) (Schaefer & Potylycki, 1993). Limitations in the research were the small sample size (n = 38), selection bias, lack of a comparison group, and use of a single-item visual analogue scale (VAS) to measure severity of fatigue. The patients' inactivity related to hospitalization and the severity of illness may also have confounded the results. Friedman and King (1995) documented that fatigue is the most common physical symptom experienced by older women with heart failure and that fatigue 19 significantly increases with time. Fatigue ranging from a little bit to severe was reported by 76% of the subjects at Time 1 and 91 % of the subjects at Time 2. Fatigue was measured 18 months apart using a physical symptom checklist containing 34 symptoms. Correlates of fatigue were physical symptonls, sleep difficulties, chest pain, and weakness at baseline and dyspnea with the second measurement at 18 months. State negative and positive affectivity and indicators of the severity of disease were not associated with fatigue. The limitations were that subjects were not at the same place in their disease progression at Time 1, high attrition (29 %) at Time 2, examining exclusively women, and measurement of fatigue as a single item embedded in a symptom checklist. Dracup and colleagues (1992) studied the quality of life in a sample of 134 subjects with CHF who were mostly men (83 %) and an average age of 50. They concluded that interventions to improve the quality of life should target mood disturbances such as depression and hostility and aim to increase daily activity levels. The combination of depression, hostility, and perceived functional status explained 43 % of the variance in psychological adjustment. Fatigue was reported to limit physical activities in 19% of the sample, and shortness of breath was reported to limit activities in 45 % of the sample. The mean perceived functional status measured by the HFFSI was 5 metabolic equivalent of tasks (METs) but was highly variable ranging from 1.0 to 7.8 METs. METs, as measured by the HFFSI, correlated with the 6-minute walk and NYHA classification but not L VEF. External validity was limited in this study because the sample consisted of mostly younger men who had been referred for evaluation for heart transplant. Fatigue was not the focus of the study but emerged as a symptom that limited physical activities. Oka and colleagues (1993) examined daily physical activity levels in CHF and found a 16 % incidence of fatigue in their sample (n = 45) of mostly men 20 (83 %) with an average age of 60 recruited from a cardiology clinic. The investigators described low levels of peak daily physical activity in their sample, with nearly half reporting no symptoms. They concluded that patients with CHF may purposely restrict their activity levels to avoid symptoms that, in turn, may predispose them to physical deconditioning. When older persons with CHF self­impose activity restrictions to avoid symptoms, sedentary lifestyles lead to disuse and muscular atrophy Iweakness that, in tum, lead to fatigue at even lower levels of activity. Individuals continue to reduce activity levels in order to avoid fatigue and other symptoms. This vicious cycle poses a serious health risk to older adults. Hawthorne and Hixon (1994) reported preliminary results of a pilot study of a nurse-monitored symptom management program designed to prevent hospitalization and emergency visits for patients with NYHA class III and class IV CHF. Both the POMS and the HFFSI were used in this study of 29 subjects whose average age was 56 years. The researchers reported a high level of mood disturbance, with highest disturbances in fatigue-inertia and tension-anxiety on the PO MS. The subjects' activities were limited by shortness of breath (63 %) and fatigue (13 % ). MET levels obtained on the HFFSI were used to stratify the sample 21 into two groups: (a) high activity and (b) low activity. An interaction effect between groups was found for global mood disturbance, fatigue, and vigor. The researchers concluded that patients reporting lower activity levels may experience a very different illness trajectory than those reporting higher activity levels. The study was limited by a small sample, high attrition, and the lack of female subjects. In addition, fatigue was conceptualized as both a mood disturbance and a symptom. Support for the validity of the HFFSI was found. In a related study, Fontana (1996) reported the relationships between vigor, exercise, and functional status in 54 subjects with CHF. No mention was made of fatigue in this study, and vigor was nleasured as the vitality score on the SF-36. Higher vigor scores were found in persons with CHF who reported retrospectively having a regular exercise habit, but differences in vigor scores were not significant. No associations between age and vigor were found. Summary of Limitations and Gaps in Current Research The few studies on CHF-related fatigue have been cross-sectional and descriptive without a comparison group and were limited by small sample sizes. Subjects have been mostly men, and many were younger than 65. Friedman and King (1995) conducted the only longitudinal study. Research supports that fatigue is a common symptom of CHF; however, the prevalence varied from 16% to 91 % across the studies. The mechanism of fatigue in CHF is not known. Fatigue is a distressing symptom that restricts physical activities, but the impact of fatigue on physical functioning has not been the focus of research attention. Fatigue is 22 associated with other physical symptoms, including sleep disturbances, but is not consistently found to be associated with emotional symptoms. The pattern of association of fatigue with age, gender, and mood disturbances is inconsistent in the studies reviewed here. Instrumentation issues plague the interpretation of the results of research focused on fatigue. Fatigue has been discovered as an incidental finding from a symptonl checklist (Friedman & King, 1995), measured by clinician-rated tools (Mayou et al., 1991), and with a single-item scale with questionable reliability (Schaefer, 1990; Schaefer & Potylycld, 1993). The measurement of fatigue can be strengthened by using self-report, multiitem scales that are reliable and valid in older individuals with CHF and are congruent with the definition of fatigue as a subjective phenomenon. Factors Associated with Chronic Heart Failure-Related Fatigue Aging and fatigue are believed to coexist; however, age was not found to be associated with fatigue in the general population (Chen, 1986). In contrast, Mitchell (1986) commented that fatigue is common in the elderly and may result in the acceptance of fatigue as a normal symptom of aging. This belief is counterproductive in the maintenance of health in older adults. Age was positively associated with the severity of fatigue in Schaefer and Potylycki's (1993) study, yet no correlation between age and fatigue was found in a subsequent study (Friedman 23 & King, 1995). The elderly may expect to feel fatigued as they age and respond by adjusting and accepting fatigue as normal (Schaefer & Potylycki, 1993), The expectation of fatigue resulting in adaptation may lead to a lowered perceived fatigue and underreporting, This response-shift phenomenon theoretically could cause fatigue levels in older adults to be lower than fatigue levels in younger adults (Breetvelt & Van Dam, 1991). Age-related differences in fatigue were found in cancer patients receiving treatment, with older patients reporting less fatigue than younger patients (Stephen & Nail, 1997). In related research, when symptoms were attributed to age, there was an underreporting of symptoms and a tendency not to seek medical help (Prohaska, Keller, Leventhal, & Leventhal, 1987). Older adults with CHF may be more likely than their younger counterparts to attribute CHF-related fatigue to aging and less likely to report this symptom to health care providers. Clinicians believe that symptoms such as fatigue increase when CHF becomes decompensated; however, there is no research supporting this notion. Thus, if older adults ignore an increase in fatigue or ignore increased fatigue because of attribution to age, a delay in seeking medical help results. Research is needed to determine the association between age and fatigue. Gender Fatigue predominates in women in the general population, with 20 % of women reporting fatigue compared to 14% of men (Chen, 1986). In research on fatigue and CHF, samples have consisted mostly of men. Dracup and colleagues 24 (1992) reported no significant gender differences in any quality-of-life outcomes in which fatigue was one of the symptoms identified as limiting physical activities. However, only 17.2 % of their sample were female. Friedman and King (1995) studied older women with CHF, which did not allow for comparison with men. The gender differences in fatigue for individuals with CHF have not been described. Much of the research on CHF and symptoms has included only men or a small percentage of women. The gender gap is reduced in older adults with CHF, and the effect of gender is unknown. In related research, women with recurrent ventricular dysrhythmias reported lower functional status scores on the HFFSI than men (! = 2.84, df = 91,12 = .006) (Dunbar, Jenkins, Hawthorne, & Porter, 1996). The results did not include the frequency of symptoms that limited activities or differences in symptoms by gender. The sample was comprised of 17 % women and included some individuals with CHF associated with left ventricular dysfunction. Comorbidity The presence of one or more illnesses other than CHF may contribute to fatigue. In the general population, fatigue was correlated with anemia, arthritis, emphysema, and asthma (Chen, 1986). The presence of systemic diseases associated with fatigue such as cancer, rheumatoid arthritis, lupus, multiple sclerosis, and fibromyalgia needs to be considered in order to avoid diagnostic confounds. Coexisting diseases such as osteoarthritis, diabetes, hypothyroidism, mild lung disease, and gastrointestinal disorders not typically associated with 25 fatigue are less likely to confound the results. Anemia and fatigue were weakly correlated in women but not men in the general population (Chen, 1986). No correlation was found between hemoglobin and the severity of fatigue in persons with CHF (Schaefer & Potylycki, 1993). In renal patients, no association was found between hematocrit and fatigue, and nearly half the sample were receiving erythropoietin therapy for severe anemia (Brunier & Graydon, 1993). Anemia is not considered an important variable in this study but was treated as a comorbidity. Hemoglobin and hematocrit were recorded on the clinical data form based on the most recent complete blood count in the medical record. Deconditioning A sedentary lifestyle is positively associated with fatigue, and physical activity is negatively associated with fatigue independent of gender in the general population (Chen, 1986). New guidelines for managing persons with CHF advocate advising all patients with stable CHF to participate in regular exercise in order to prevent physical deconditioning (Guidelines, 1995; Konstam et al., 1994). Fatigue associated with CHF has been found to coexist with breathlessness on exertion, skeletal muscle atrophy, and peripheral vasoconstriction leading to impaired skeletal muscle oxygenation (Clark, Sparrow, & Coats, 1995; Drexler & Coats, 1996). Since deconditioning may be an important causative factor of fatigue in CHF, self-report of regular exercise was collected. Subjects who had performed any exertional activities recently were asked to rate the intensity of their exercise 26 using the Borg scale of perceived exertion (Borg, 1982). Sleep Disturbances Sleep difficulties and fatigue were positively correlated (r = .48, R < .001) in older women with CHF (Friedman & King, 1995). Sleep disturbances in persons with CHF may be caused by a variety of factors, including difficulty breathing when lying flat, paroxysmal nocturnal dyspnea, and urinary frequency. Recent studies have described the high prevalence of sleep-disordered breathing associated with CHF (Javaheri et aI., 1995). Javaheri (1996) reported that 45% of subjects with stable CHF (n = 42) had an apnea-hypopnea index of more than 20 per hour associated with frequent arousals and arterial oxyhemoglobin desaturation. Brown (1997) hypothesized that the Cheyne-Stokes respirations commonly experienced by persons with CHF may be a central sleep apnea caused by decreased perfusion of the brainstem ventilatory controller. Thus, sleep-disordered breathing, nocturnal hypoxemia, and frequent arousals may contribute to the sensation of fatigue. The effect of nocturnal oxygen in patients with CHF who had Cheyne-Stokes respirations was tested, resulting in improved exercise capacity but not a significant difference in daytime symptoms (Andreas, Clemens, Sandholzer, Figulla, & Kreuzer, 1996). Persons with diagnosed sleep disorders, continuous oxygen therapy, or both were excluded. The presence of sleeping difficulty and associated severity was measured. 27 Pain severity was one of the few physiological variables found to correlate strongly with fatigue in cancer patients (r = 0.48, 12 < .0001) (Blesch et al., 1991). The impact of cardiovascular pain such as angina on fatigue has not been determined. A sample of individuals more than 65 years old may have other sources of pain in addition to cardiovascular disease. Other potential pain experiences should be included on the symptom checklist in order to explore associations between a person's complaint of pain and intensity of fatigue. Mood Disturbances Chen (1986) found that psychological factors such as depression, anxiety, and stress were strongly associated with fatigue in the general population. In contrast, psychological variables did not contribute to the intensity of fatigue in older women with CHF (Friedman & King, 1995). However, Dracup and colleagues (1992) reported that depression, hostility, and linlited function accounted for 43 % of the variance in psychosocial adaptation in subjects with advanced heart failure. Since it is not known how mood disturbances contribute to fatigue in older adults with CHF and results are inconsistent, subjects with depression were excluded. Medications Fatigue is included as a side effect in the long list of possible adverse reactions for many medications. Beta blockers are associated with increased fatigue 28 when initially prescribed, which may improve over time. Fatigue is not a primary side effect with digitalis, diuretics, potassium supplements, angiotensin receptor blockers, or angiotensin-converting enzyme inhibitors. Centrally acting medications such as antidepressants, hypnotics, narcotics, and antipsychotics may increase fatigue or alter the perception of fatigue. All medications must be known in order to test any association with fatigue. Subjects receiving centrally acting medications known to cause fatigue or drowsiness were excluded from the study. In addition, subjects with a diagnosed psychiatric disorder were not enrolled. A complete list of each subject's medications, along with prescribed dosages, were documented on the clinical information form. Number of Symptoms Cardiac symptoms. Sleep difficulty, chest pain, and weakness were associated with fatigue in older women with CHF (Friedman & King, 1995). Eighteen months later dyspnea was the only variable associated with fatigue, and only 9 % of the variance in fatigue were explained by dyspnea. Mayou and colleagues (1991) found fatigue to be associated with other physical symptoms such as breathlessness, chest pain, difficulty sleeping, and palpitations. In the present research, common symptoms of CHF and the severity of the symptoms endorsed were measured. Age-related symptoms. No research has examined the relationship between fatigue and age-related symptoms. Many of the research studies on CHF have been directed at a younger sample, particularly noticeable in research that takes place at 29 heart transplant referral centers. Age-related symptoms such as leg cramps, constipation, painful joints, and weakness were included on the symptom checklist. Because distress caused by other symptoms may contribute to fatigue in other adults, the total number of symptoms and symptom severity should be considered in research on fatigue in CHF. Atrial Fibrillation Atrial fibrillation is an arrhythmia common in CHF in which the atria of the heart do not contract as a unit, resulting in loss of ventricular filling during end diastole. The disturbance in end-diastolic filling results in a loss of atrial kick. The chaotic atrial electrical activity causes an irregular pulse and beat-to-beat variations in the amount of blood pumped out of the heart. Atrial fibrillation may result in a 15 % to 30 % reduction in cardiac output, yet it is well-tolerated by most individuals at rest (Guidelines, 1995). Symptoms of fatigue, dyspnea, and exercise intolerance may be experienced with activity, particularly when the ventricular heart rate is not controlled. Medications are frequently used to control the heart rate of individuals in atrial fibrillation. In a study describing daily activity levels in CHF, 18% of the sample had documented atrial fibrillation (Oka et aI., 1993). The investigators did not comment on tlle extent that atrial fibrillation contributed to fatigue in this sample, with fatigue reported in only 19% of the sample. In this research, subjects with atrial fibrillation were included, and any relationship between fatigue and the presence or absence of atrial fibrillation was examined. 30 In conclusion, descriptive research on CHF-related fatigue was needed to explore this poorly understood phenomenon and to identify factors associated with fatigue. In addition, research is needed to compare fatigue in men and women. A priority was to focus on adults aged 65 and older in whom the incidence of CHF is increasing rapidly. Heart transplantation, in general, is not offered to older patients, making research conducted by transplant-referral centers biased towards younger patients with advanced CHF. The successful medical management of older adults with advanced CHF is crucial. Information about CHF-related fatigue and its correlates, along with a description of the impact of fatigue on functional status, will guide interventions designed to prevent and reduce fatigue. Operational Definitions Fatigue Fatigue is the self-perceived sensation that is unpleasant and can cause distress. Fatigued individuals may describe the sensation as being tired or feeling exhausted. Fatigue is different than weakness. Fatigue is not the opposite of energy or vigor, although these concepts are associated with fatigue both closely and negatively. In patients treated for cancer, the correlation between the words energetic and fatigued was -.63 (Nail et aI., in review). Fatigue severity was measured as the score on the fatigue sub scale of the POMS-Short Form (POMS-st) (McNair, Lorr, & Droppleman, 1992). In addition, global fatigue was measured with a VAS. Vigor scores were available from the POMS-sf and were computed to compare with other research fmdings. 31 Disruption of Lifestyle Disruption of lifestyle is the impact on daily life that is directly related to having CHF. The LlhFE was used to measure disruption (Rector & Cohn, 1992). Activities impacted by CHF were described with the LlhFE. Self-Perceived Functional Status Self-perceived functional status is the self-report of the capacity to perform physical activities. The HFFSI was used to measure self-perceived functional status (Dracup et al., 1992). Subjects identified the activities they could and could not perform and the symptoms that limit the performance of activities. Scoring of the HFFSI resulted in a total score indicating the METs and provided information about the symptoms that limit physical function. Chronic Heart Failure Chronic heart failure (CHF) is "a clinical syndrome or condition characterized by (1) signs and symptoms of intravascular and interstitial volume overload, including shortness of breath, rales, and edema or (2) manifestation of inadequate tissue perfusion, such as fatigue or poor exercise tolerance" (Konstam et al., 1994, p. 11). Subjects were eligible for this study if they had been diagnosed with CHF for at least 6 months. Left Ventricular Systolic Dysfunction Left ventricular systolic dysfunction is an abnormality of the pumping function of the left ventricle. Left ventricular systolic dysfunction was defined as a 32 LVEF ~ 0.40 by echocardiography, radionuclide ventriculography, or cardiac catheterization with left ventricular ventriculography (Konstam et al., 1994). Differences in calculated L VEF across methods were judged to be irrelevant to this study. Individuals diagnosed with CHF, but without measured L VEF, were ineligible in order to avoid including persons without CHF. Those with CHF and an isolated diastolic dysfunction were not included. Older Adult In this study, an older adult was an individual 65 years and older. Exact age in years was documented in order to allow age to serve as a demographic variable. Severity of Illness In this sample, severity of illness ranged from mild to severe. The NYHA classification was used to categorize individuals into four groups based on when symptoms occurred (Criteria Committee, 1964). Class I was an individual who met the criteria for having CHF and was symptom free regardless of activities. Class II was an individual who had dyspnea with ordinary activities. Class III was an individual who had dyspnea during less-than-ordinary activities. Class IV was an individual who experienced dyspnea at rest, with any activities resulting in symptoms of fatigue, dyspnea, palpitation, or angina. The clinician's appraisal of the subject's classification was used when this information was recorded in the medical record. When NYHA classification was not previously documented, the 33 classification was assigned based on the subject's synlptoms. In addition, severity of illness was reflected by L VEF, with smaller values occurring with a more compronlised left ventricle, resulting in a lower cardiac output, and, thus, a more severe CHF. Subjects were enrolled in the study if their LVEF was..$.. 0.40. The value of the LVEF was collected from the medical record and used to control for the effects of the severity of illness. An additional measure for the severity of illness was the number of cardiac medications necessary to manage and stabilize CHF. An individual with a more severe CHF likely would be on quadruple therapy such as an angiotensin converting enzyme inhibitor, digitalis, beta blockers, and diuretics. Milder forms of CHF may require only an angiotensin converting enzyme inhibitor to prevent progression of the syndrome. Medications were recorded to classify subjects by the number of the usual medications used to manage CHF. Quality of Life The aspects of quality of life in addition to physical functioning were measured. Symptoms were assessed with a questionnaire modified from a version used with cancer patients (Nail, Jones, Greene, Schipper, & Jensen, 1991). Subjects were asked about the presence of common symptoms associated with CHF and aging. The frequency and severity of symptoms were measured. Psychological well-being was measured using the Positive and Negative Affect Schedule (PANAS) and the Satisfaction With Life Scale (SWLS) (Diener, Emmons, Larsen, & Griffin, 1985; Watson, Clark, & Tellegen, 1988). The PANAS determined the 34 affective component of psychological well-being. The SWLS measures global life satisfaction and is based on a judgment made by the individual assimilating a host of variables. Purpose and Research Questions The purpose of this study was to describe fatigue in older adults with CHF and the relationships among severity of fatigue, demographic and clinical variables, and perceived functional status. Individuals with diagnosed CHF and evidence of left ventricular systolic dysfunction were included. Those with CHF related to isolated diastolic dysfunction were not studied. Inclusion and exclusion criteria were applied in an attempt to isolate fatigue associated with CHF. The research questions follow: 1. What are the prevalence and intensity of fatigue in older men and women with CHF secondary to left ventricular systolic dysfunction? 2. What is the relationship of fatigue to self-perceived functional status in older men and women with CHF secondary to left ventricular systolic dysfunction? 3. When controlling the severity of illness, what combinations of clinical and demographic variables (age, gender, marital status, age attribution, duration of CHF, L VEF, number of medications, and atrial fibrillation) explain fatigue in older men and women with CHF secondary to left ventricular systolic dysfunction? 35 Theoretical Framework Leventhal's common-sense model (Leventhal & Johnson, 1980) provided the conceptual framework for this research. As an informational processing model based on the illness representation, the common-sense model has utility in research about symptoms in chronic illness. "According to this model, symptoms are key factors in the cognitive representation of health threats, they are targets for coping, and symptom amelioration is critical for the appraisal of progress in mitigating the health threat" (Cameron, Leventhal, & Leventhal, 1993, p. 171). Many nursing studies have been guided by Leventhal's work, including a recent study of the symptoms reported by hospitalized patients with CHF (Friedman, 1997). The common-sense model has three components: (a) illness representation, (b) coping, and (c) appraisal. The model is based on the notion that individuals are motivated to understand their symptoms, and their unique mental representation of a symptom experience is what guides the subsequent actions taken to cope with the symptom in an effort to reduce health threats (Leventhal et aI., 1984). Simply stated, an individual's interpretation of symptoms drives coping. Coping refers to the actions taken in response to the illness representation and is targeted at both the symptoms and any associated emotional distress caused by the symptoms. Prohaska and colleagues (1987) defined coping as "a set of cognitive, affective, and behavioral efforts to contend with illness" (p. 500). Appraisal is the evaluation of the effectiveness of coping based on a set of rules (Keller, Ward, & Baumann, 1989; Leventhal, 1990). Appraisal can feed back to alter coping, illness 36 representation, or both resulting in a recursive systenl (Leventhal et al., 1984). The findings of this research were linked to illness representation of the common-sense model. No attempt was made to test the model in this descriptive study. The initial stage (illness representation) is when individuals organize, analyze, and interpret internal and external information (Ward, 1993). Illness representation is composed of identity, cause, timeline, consequences, and cure (Leventhal et aI., 1984; Ward, 1993). Symptoms are bodily sensations that are interpreted and given meaning by an individual. Identity refers to the symptom experience and the label associated with the illness. The measurement of the intensity of fatigue in this research focused on the identity aspect of illness representation. Consequences are often the disturbances in functioning caused by the symptom and were operationalized as the score on the LIhFE (Rector & Cohn, 1992). Timeline is considered a constant; that. is, subjects have a chronic illness of at least 6 months duration. However, timeline, cure, and cause were not measured from the individual's perspective in this study. Because fatigue ,is a common symptom in CHF, an illness representation is created and stimulates a coping response based on the bodily sensation of fatigue. Coping behaviors initiated in response to fatigue often involve alterations in activity level. Thus, coping was operationalized as self-perceived functional status and was measured with the HFFSI (Dracup et aI., 1992). The HFFSI allows for the differentiation of individuals who function at high activity levels (MET greater than or equal to 5) from those functioning at low activity levels (MET less than 5) 37 (Hawthorne & Hixon, 1994). A limitation in selecting the common-sense model to guide this research was that the illness representation changes over time. The processing that occurs with illness representation is dynamic based on many sources of information and is updated continuously with new data (Ward, 1993). Cross-sectional designs capture phenomena at a single time period. Thus, only a slice of the ever-changing illness representation was measured, and this slice of time was different for each subject. In addition, appraisal and the mechanisms linking representation, coping, and appraisal were not studied. Another limitation of the model was that other symptoms and side effects did not fit easily into the framework. In a study about CHF in the elderly, several symptoms and side effects of prescribed treatments were known to coexist with fatigue. Symptoms, other than the target symptom, could be designated as life stressors in the common-sense model. However, life stressors are shown to interact with emotional states but not illness representation, whereas symptoms are likely to interact with both emotional states and illness representation. Previous research has demonstrated that other symptoms are associated with fatigue in persons with CHF (Friedman & King, 1995; Mayou et aI., 1991). Symptoms and their severity were measured in this research, and any relationships found between other symptoms and fatigue were described. An important assumption of the common-sense model is that processing takes place on two parallel pathways: (a) cognitive and (b) emotional (Leventhal et al., 1984). The latter pathway consists of the emotional response to illness and the 38 coping procedures to deal with any associated distress. Appraisal refers to an evaluation of whether or not coping procedures have reduced negative emotional responses. Emotional state was not measured in this study; however, the PANAS was employed to assess trait-negative affectivity as a possible confounding variable (Watson et aI., 1988). The rationale for selecting the trait PANAS is to control for the effect of trait-negative affectivity on fatigue. Satisfaction with life as a global measure was assessed as an indicator of coping with the affective state. The emotional dimension on the LlhFE served as an indicator of how heart failure disrupts the emotional state. Another assumption of the common-sense model is that the information­processing system is organized hierarchically (Leventhal et al., 1984). Although more recently, Leventhal (1990) clarified that the information-processing system is multilevel rather than hierarchical. That is, illness representation occurs at both concrete and abstract levels. Fatigue may be represented at the concrete level as the sensation of feeling weak and tired with heavy legs and having difficulty problem solving. On an abstract level, fatigue may be viewed as a weakened heart muscle unable to keep up with the body's demand for oxygen. The quantitative approach used in this research did not allow for the comparison of concrete and abstract descriptions of fatigue. Prohaska and colleagues (1987) found that coping is affected by age. Older individuals were more likely to choose rest and relaxation as coping responses to illness. The attribution of symptoms to aging is more common in older individuals 39 and occurs more frequently with milder symptoms. Fatigue associated with CHF may be interpreted as a mild symptom and is likely to be attributed to aging, especially in older subjects. According to the work of Prohaska and colleagues, older adults with CHF are more likely to attribute their fatigue to aging, to choose coping strategies that include rest and relaxation, and not likely to discuss their symptom of fatigue with medical care providers. Unfortunately, this common-sense interpretation of a symptom such as fatigue in adults with CHF may lead to misguided coping like adopting a sedentary lifestyle and delaying treatment for the exacerbation of CHF. In a retrospective review of 181 charts of hospital admissions due to CHF, Friedman (1997) found that fatigue was not reported as a symptom. A single item was developed in an attempt to measure the attribution of fatigue to aging. No standard approaches were found to measure age attribution. Independent of age, the duration of CHF may affect the illness representation of fatigue. The length of time an individual is diagnosed with CHF was recorded to determine any impact on symptom interpretation (Baumann, Cameron, Zimmerman, & Leventhal, 1989). In summary, the present research was grounded in the common-sense model. Models guided the study, functioned to provide organization, and provided a theoretical context to interpret the fmdings (Polit & Hungler, 1995). The descriptive design and the absence of hypotheses prohibited the testing of the common-sense model. Many study variables were linked directly to the concepts of the common-sense model; however, additional variables were measured based on the literature review on fatigue and CHF. 40 CHAPTER III METHODS This research study investigated fatigue in older adults with CHF associated with left ventricular systolic dysfunction. Specifically, the study was designed to describe the prevalence and intensity of fatigue and to examine the combination of demographic and clinical variables that explain fatigue. The research was guided by the common-sense model, with emphasis on symptoms as the central focus designated as the illness representation. The underlying assumption was that knowledge about symptoms was learned from the individual's perspective. Data were collected by questionnaire administered face to face by me and consisted of responses on a demographic form and several scales measuring fatigue, self-reported functional status, positive and negative affect, life satisfaction, and symptoms. Clinical variables were obtained from medical records and were verified with the subjects when appropriate. The methodology, research plan, and procedures for data analysis are described in this chapter. Design A descriptive, correlational design was employed, and quantitative data were collected. This design is also known as an ex post facto design (Polit & Hungler, 1995). A prospective study was planned in order to optimize the 42 description of the sensation of fatigue from the subject's viewpoint. A retrospective study was considered; however, data that describe fatigue from the person's perspective were not found in existing medical records. The ultimate goal of testing interventions that reduce CHF-related fatigue cannot be achieved without the groundwork laid by descriptive studies. The results of this research are needed in order to guide the development of sensitive outcome measures and fatigue-reducing interventions, along with the identification of confounding variables. Thus, the selection of a descriptive, quantitative design was justified by the lack of empirical research focusing on fatigue in older adults with CHF (Polit & Hungler, 1995). The design did not allow inferences regarding causality. However, the method is an efficient way to obtain information about a phenomenon and correlates, and it was judged most appropriate considering time and cost constraints (Polit & Hungler, 1995). Sample A convenience sample of 55 community-dwelling men and women at least 65 years old was enrolled from ambulatory care sites in southwestern Idaho. The clinical sites consisted of cardiology, internal medicine, and family practices. Family practice and internal medicine clinics were included in order to obtain a sample that was more representative of the elderly CHF patient. However, all patients in this study had a cardiologist who managed their CHF, a reflection of both access to a cardiologist and the community standard of cardiac care. 43 Sample size was projected prior to the research based on the ratio between subjects and independent variables. A ratio of 10 to 1 was needed for an R2 of 0.23 or higher in order to be statistically significant with a power of .80 (Hair, Anderson, Tatham, & Black, 1995). The power analysis allowed five independent variables in the multiple regression model, with a sample size of 53. Inclusion and exclusion criteria were established in an attempt to isolate fatigue associated with CHF. Inclusion criteria included the following: (a) 65 years of age or older, (b) diagnosed with CHF for at least 6 months, (c) documented systolic dysfunction with a L VEF ~ 0.40, (d) compensated CHF as evidenced by stable medication regimen (medications not adjusted for 3 weeks) and physician's assessment that CHF was stable, (e) able to speak and read English, and (t) community dwelling (not hospitalized or living in an extended care facility). Exclusion criteria were the following: (a) major surgery (heart, vascular, abdominal, and orthopedic) within the past 6 months; (b) stroke within the past 1 year; (c) cancer diagnosis and treatment within the past 5 years, with the exception of precancerous or nonmelanoma cancerous skin lesions; (d) moderate to severe chronic obstructive pulmonary disease; (e) cor pulmonale; (t) altered thought process such as dementia, delirium, confusion, anxiety disorder, or psychosis; (g) kidney disease requiring hemodialysis or peritoneal dialysis; (h) receiving continuous oxygen therapy; (i) diabetes associated with serious complications; G) homebound status receiving home health nursing services; (k) diagnosed sleep disorder; (1) depression; (m) receiving sedatives, narcotics, anxiolytics, or 44 antipsychotics; and (n) rheumatological disorders such as fibromyalgia, rheumatoid arthritis, polymyalgia rheumatica, or lUpus. Subjects on beta blockers were excluded initially. However the standard of care changed; that is, many CHF patients were prescribed this class of medication. The exclusion of subjects on beta blockers was removed in order to accrue a sample representative of current CHF management practices. The exclusion criteria were necessary in order to isolate fatigue associated with CHF and to eliminate known confounding variables. Setting The community setting was selected in order to optimize the recruitment of subjects with stable heart failure. Most participants were interviewed in their homes. Some of the participants were interviewed in their physicians' offices when this arrangement was more convenient to the participant. Recruitment took place in an urban area in southwestern Idaho. However, some participants resided in a rural location as far as 70 miles away from the metropolitan area. Residence was recorded as urban if participants lived within the major city and rural if they did not live within the city limits. Two regional medical centers and a veterans hospital, each offering cardiac care services, are located within the city limits and serve a large surrounding region of southwestern Idaho. Description of the Instruments Demographic Questionnaire 45 Demographic variables, including age, gender, education level, marital status, living alone or with another, employment status, and ethnic background, were collected with a questionnaire crafted by me (Appendix A). In addition, subjects were asked if they were caregivers defined as being responsible for another person who is unable to care for himself or herself. Global health status was assessed with a question asking subjects to rate their current health on a 4- point scale from excellent to poor. Adherence to the medical regimen was measured with questions about medications, dietary sodium restriction, monitoring daily weights, and exercise routines. The demographic questionnaire was ordered last because responses were less likely to be affected by the subjects' fatigue, and then I could read the questions and record their responses. Clinical Information Clinical variables were collected from the medical record using an investigator-generated form (Appendix B). The following variables were recorded: (a) duration of CHF in months, (b) cause of CHF, (c) LVEF, (d) NYHA classification, (e) comorbidities, (f) atrial fibrillation, (g) 83 gallop, (h) angina, (i) last three clinic blood pressures, (1) last three clinic pulses, (k) last three clinic weights, (1) names and dosages of all prescription medications, and (m) over-the­counter medications. The participants were asked to verify the clinical variables likely to change such as current medications. In addition, environmental factors 46 that may influence fatigue were documented on the clinical information form such as time of day, day of the week, season, outdoor temperature, and weather pattern. Profile of Mood States-Short Form Fatigue was measured using the POMS-sf fatigue subscale (McNair et aI., 1992). The POMS is a reliable and valid scale that has been widely used in populations with chronic illnesses. The original version was abbreviated based on the results of factor analysis from 65 to 30 items to yield the short form. The POMS-sf consists of a list of 30 adjectives rated on a 5-point Likert scale and includes six subscales: (a) fatigue-inertia, (b) vigor, (c) tension-anxiety, (d) depression-dejection, (e) anger-hostility, and (t) confusion-bewilderment. The 30- item scale was administered; however, only the POMS-sf fatigue sub scale (POMS­F) and the POMS-sf vigor sub scale (POMS-V) were used as outcomes. Scores of the POMS-F and the POMS-V range from 5 to 25, with higher scores reflecting high intensity of fatigue and vigor, respectively. Standardized instructions were provided, and the POMS-sf was self- or investigator-administered. When I administered the POMS-sf, a response card was used in order for subjects to read the possible responses as the 30 adjectives were read. Subjects verbalized their responses after each adjective, and then I circled the response on the questionnaire. All subjects were instructed to rate the way they felt during the past week. The purpose of the I-week rating period was to learn the typical intensity of fatigue but to provide a short enough period to reduce measurement error caused by recall. The POMS-sf was the first scale administered 47 in order to minimize the effect of subject fatigue. The POMS-F was valid, reliable, and a sensitive measure of fatigue in a recent instrument comparison in cancer patients (Meek et al., in press). Internal consistency reliability was excellent for the 5-item POMS-F, with a Cronbach's alpha of 0.95 (Meek et aI., in press). Stephen and Nail (1997) found the POMS-F to be a reliable and valid measure of fatigue in adults with cancer who were 65 years and older. The original POMS and POMS-sf have been used in cardiac patients for measuring mood disturbances; however, problems found with fatigue and lack of vigor suggested abnormalities in physical rather than in emotional recovery (Hawthorne & Hixon, 1994; King, 1985; King, Porter, & Rowe, 1994). The POMS-F has not been used as a measure of fatigue in older adults with CHF. Internal consistency was calculated for this sample using Cronbach's alpha. The POMS-F had an alpha of 0.82, and the POMS-V had an alpha of 0.80, both supporting adequate internal consistency reliability. The five items in the PO MS-F had face validity. Concurrent validity was supported with a positive correlation to VAS-F (r = .52, 12 < .001) and a negative correlation to POMS-V (r = -.43, 12 < .001). Visual Analogue Scale for Fatigue A single-item VAS (VAS-F) was included to measure global fatigue using the standardized 100-millimeter horizontal line labeled at the two extremes (Blesch et aI., 1991; Mock et aI., 1994; Schaefer & Potylycki, 1993). The end-points of the VAS-F were labeled no fatigue and exhausted, which is consistent with the 48 definition of fatigue (Appendix C). A second V AS item, V AS-W, was included in order to distinguish between fatigue and feelings of weakness (Nail & Winningham, 1995). The end-points for these concepts were no weakness and extreme weakness. Gift (1989) advocated the use of the V AS as a reliable and valid measure of subjective phenomena and suggested that the level of measurement is continuous. Reliability, other than test-retest reliability, cannot be demonstrated in a single-item scale. However, the simplicity and ease of use have made VAS items popular in clinical practice. The rationale for selecting the VAS-F in this study was to provide a backup measure for the study variable of interest and to compare results of other studies of patients experiencing fatigue (Blesch et aI., 1991; Mock et aI., 1994; Schaefer & Potylycki, 1993). VAS scales were administered following the POMS-sf with written and verbal instructions on how to mark the scale. Subjects rated their fatigue and weakness over the past week. They were provided a practice V AS for hunger to assist with both the correct marking of the scale and thinking in global terms. In addition, they were supplied with a pen to reduce problems with wide marks on a V AS scale, which could contribute to measurement error. After rating their feelings using VAS scales, subjects were asked a single question to determine the extent to which they attributed their fatigue to aging. Using a 4-point scale, subjects responded to how likely they believed their tiredness and fatigue were due to aging from very unlikely to very likely due to my aging. If they had no fatigue, 49 they marked not applicable. The reliability of my scoring of the V AS was determined through the use of a second trained assistant who independently scored all V AS results. Interrater reliability of 90 % agreement or higher was selected as a minimal standard. The following rules for scoring the V AS items were followed by both raters to reduce measurement error: Score on a flat, well-lighted surface; use a clear plastic ruler divided into millimeter markings; match the zero point of the ruler with the left end of the scale; marks located between 2 millimeters were rounded toward the center of the line; when an X crosses the scale, score where the X intersects the scale; and if the X or mark does not intersect the scale, score where it would intersect the scale if it had crossed. Pearson product-moment correlations between raters for the independently scored VAS scales were 1.00 for all three scales. Percentage agreement was 88.7 for practice hunger, 90.6 for V AS-F, and 88.7 for V AS-W. All disagreements in scoring were 1 millimeter differences. Heart Failure Functional Status Inventory Functional status, defmed as the capacity to perform daily activities, was measured using the HFFSI (Appendix D). The instrument is a 12-item, self-report questionnaire that was adapted from a health status measure for use with individuals with heart failure (Dracup et al., 1992). Each item identifies an activity, and the subjects answer, "Yes, I can do this," "Yes, I can do this, but only slowly," or "No, I can't do this." When subjects responded that they performed an activity slowly, they were asked to identify the symptom that limits the activity from the following: (a) shortness of breath, (b) weakness without shortness of breath, (c) fatigue, (d) chest pain, or (e) some other reason. 50 The metabolic demands of each activity have been identified by a group of experts (Dracup et al., 1992). One MET is equal to 3.5 milliliters oxygen per kilogram of body weight per minute and is the approximate energy consumed when lying quietly at rest. The HFFSI allows for the estimation of the MET level of daily activities. The average of the three highest MET levels assigned to activities that subjects indicated a "yes" or "yes, but slowly" responses were calculated to obtain the individual's MET level (Dunbar et al., 1996). Internal consistency reliability was demonstrated with a Cronbach's alpha of 0.84 in a sample of patients with a dangerous cardiac arrhythmia awaiting implantation with an automatic cardioverter defibrillator (Porter, Davis, Dunbar, Jenkins, & Hawthorne, 1994). In the present study, the computation of MET levels was performed by two independent raters. The percentage agreement was 98. Minnesota Living with Heart Failure Questionnaire The LIhFE is a 21-item, self-administered quality-of-life scale used to measure outcomes in intervention trials (Rector & Cohn, 1992). The questions tap alterations in lifestyle frequently attributed to CHF, and each item is rated by the subject using a 6-point Likert-type scale. Scores are obtained by summing the responses for a total score and summing the subscales for physical and emotional dimensions. Internal consistency reliability was supported with a Cronbach's alpha of 0.94 for the total score, 0.94 for the physical dimension, and 0.90 for the 51 emotional dimension (Rector & Cohn, 1992). Validity was supported for the physical dimension but not for the emotional dimension. Change in total scores and physical subscale scores were weakly correlated to changes in exercise tolerance. Rector and Cohn emphasized using the scale as a self-administered scale and to provide standardized instructions. Subjects were provided standardized instructions and were asked to rate the LIhFE independently. One subject was unable to complete the scale. Several other subjects were provided verbal assistance if they had difficulty reading the items or seeing the rating scale. Internal consistency reliability in this sample was good, with a Cronbach's alpha of 0.92 for the total scale, 0.91 for the physical subscale, and 0.86 for the emotional subscale. Positive and Negative Affect Schedule The PANAS is a 20-item measure, consisting of 10 negative and 10 positive mood adjectives using a 5-point Likert-type scale (Watson et al., 1988). Positive and negative affectivity are components of subjective well-being. The PANAS is credited with being able to distinguish depression and anxiety. The trait form of the PANAS was used to measure and control for trait-negative affectivity. Internal consistency reliability for the trait form was reported as a Cronbach's alpha of 0.87 and 0.88 for the negative and positive scales, respectively (Watson et aI., 1988). The PANAS has been found to be a reliable and valid scale in older adults (Kercher, 1992). In a sample of older women with CHF (n = 80), Cronbach's alpha for the PANAS (state version) was 0.77 for positive affectivity, with one item (excited) removed, and 0.78 for negative affectivity (Friedman & King, 1995). Internal consistency of the PANAS (trait version) in this sample produced an alpha of 0.85 for positive affectivity and 0.87 for negative affectivity, demonstrating adequate reliability. Satisfaction With Life Scale 52 The SWLS measures global life satisfaction and was selected to include a measure of subjective well-being. The score on the SWLS is based on an evaluation made by the individual of the impact of a host of variables, including symptoms and altered functional status on an aspect of quality of life (Diener et al., 1985). The measure is a 5-item, 7-point Likert-type scale in which higher scores represent greater life satisfaction. A Cronbach' s alpha of 0.87 was reported, reflecting adequate internal consistency reliability. Evidence exists for convergent validity (Diener et al., 1985). Internal consistency reliability with a Cronbach' s alpha of 0.74 was reported in a study of older women with CHF (Friedman & King, 1995). In this sample, an acceptable internal consistency reliability was achieved with a Cronbach' s alpha of 0.87 for the SWLS. Symptom Checklist (Heart Version) A symptom checklist was derived from the Side Effect Checklist and was crafted to include symptoms common in older adults with CHF (Nail et al., 1991). The tool consists of 19 symptoms identified in the literature (Appendix E). Most symptoms listed on the checklist are widely recognized to be associated with CHF; however, nocturnal enuresis, the involuntary loss of urine at night during sleep, 53 was added based on findings in an epidemiological study (Burgio et al., 1996). The investigators reported that nocturnal enuresis was associated with symptoms of CHF, impairment in activities of daily living, depression, and the use of sleeping medications once a week or more. Symptoms of CHF and the use of sleeping medications were independent predictors of nocturnal enuresis. Subjects who reported the presence of a specific symptom were asked to . rate the severity of the symptom using a 5-point Likert-type scale. The total number of symptoms and the severity of symptoms were computed to determine the relationships of fatigue and vigor. In addition, individual symptoms were tested for associations with fatigue based on the findings of other studies (Friedman & King, 1995). Procedures for Data Collection Prior to conducting this study, approvals were received from the Institutional Review Board at the University of Utah, Salt Lake City, Utah; Saint Alphonsus Regional Medical Center, Boise, Idaho; and the Human Welfare Committee at St. Luke's Regional Medical Center, Boise, Idaho. Pretesting of the questionnaire was conducted to determine readability, clarity, length of time to complete the questionnaire, and adverse effects such as fatigue. The individuals who volunteered to pretest the questionnaire had NYHA class III and class IV CHF, visual impairments, and mobility impairments. The information obtained through pretesting led to minor revisions in the questionnaire to improve clarity and the estimate that the questionnaire could be completed in 35 to 45 minutes in one appointment without excessive fatigue. Data from pretest subjects were not included in the research. 54 Physicians were approached individually, informed about the study, and requested to assist with identifying eligible patients. Permission to conduct research at each physician's office was obtained according to the facility's policy regarding research. Each office selected a contact person and process for identifying potential subjects, screening the medical record, and communicating with prospective subjects. Some sites designated a person to call all prospective subjects and to obtain their permission in order to give their phone number to a researcher. I arranged for a nurse to call eligible patients to notify them that a researcher would be calling to recruit them into the study at the other sites. Subjects were recruited from nine clinical sites of six physician practices. Physicians identified potential subjects who met the inclusion criteria. Some clinical sites offered a computer search of all CHF patients meeting the age criteria. The medical records of referred subjects were screened to assure that they met both inclusion and exclusion criteria. Eligible subjects were contacted by telephone and informed about the study. An appointment was made with prospective subjects if they were interested in enrolling in the study. Efforts to strengthen communication between me and the multiple data collection sites included a 24-hour pager number, a designated business line with message machine and caller identification, the distribution of business cards at participating ambulatory clinics identifying me as a University of Utah doctoral 55 student in nursing along with study topic, and a laminated card with inclusion and exclusion criteria. Weekly rounds were made to each clinic in order to maintain communication with physicians and staff. Potential subjects referred into the study were contacted by telephone by me after a staff member obtained their permission to be called by a researcher. The purpose of the research and the procedure for participating were communicated before making an appointment. The appointment was planned to take place at the subject's home. The appointment was estimated to take 45 minutes and was scheduled during the daytime unless subjects requested evening appointments. Written informed consent was obtained from each subject following a face-to-face discussion of the purpose of the research, risks and benefits, and rights of a research volunteer. A copy of the consent form was given to each subject. Following informed consent, the Pfeiffer Short Portable Mental Status Questionnaire was administered (Pfeiffer, 1975). A score of no greater than four errors was the cutoff in order to verify cognitive competence to participate in the study. No subjects were eliminated based on their score on the Short Portable Mental Status Questionnaire. Prior to presenting the questionnaire to the subjects, an inquiry was made about acute illnesses. If subjects were found to be suffering from an acute illness on the day of the study, a return appointment was planned in order to avoid confounding the results with the sensations associated with acute fatigue. No appointments were rescheduled because of acute illness. 56 Participants were asked to respond to a series of questionnaires. In order to reduce subject burden and to improve data quality, I was present for the completion of the questionnaire and offered assistance when needed (Carp, 1989). The instructions for filling out the questionnaire were delivered by face-to-face interview by one investigator, and the instructions were standardized. The order of presentation of the different scales was fixed to control for any effect of order. An assumption was made that subjects were more fatigued toward the end of the questionnaire packet, and a constant order was used to standardize the bias of test fatigue across subjects (Carp, 1989). Subjects were given a questionnaire packet. First they completed the POMS and the VAS scales. Then they completed the HFFSI, LlhFE, PANAS, SWLS, and a symptom checklist. The Demographic Questionnaire was completed last. When necessary, I asked the questions. I checked the completed questionnaire in order to assure that all questions were answered. The medical record served as the source of clinical data. Present medications and current weight were verified with each subject during the appointment. After the questionnaire was completed, the subjects were thanked for their participation in the study. Clinical data were obtained from the medical records following informed consent. Data were recorded on an investigator-developed clinical information form. This form and the questionnaire packet did not identify the subject by name. Instead, a code number was assigned to each subject, and this number was recorded on the questionnaire and the clinical information form. A master form of names and code numbers was locked in the file containing the signed consent forms. Geriatric Considerations 57 The age-related changes found in older adults, particularly with alterations in sensory perceptive functioning, necessitated accommodations in the planning of this study. Questionnaires were designed using a larger-than-usual point size and double spacing for ease of reading and selecting responses. A nonglossy white paper was used to improve the visualization of print. The questionnaire was completed in a comfortable chair with good lighting. Subjects were asked if they had their reading glasses, and they were allowed time to secure them if needed. Instructions were given slowly and with good enunciation. Background noise such as television was quieted when possible. A short mental status screening was included, recognizing that potential subjects may have a nondiagnosed dementia that would limit their ability to consent or participate in the study. If family members were present, subjects were encouraged to answer the questionnaire independently. Human Subjects The proposal and consent were submitted to the Institutional Review Board of the University of Utah for approval. Permission to conduct research and to contact prospective subjects was obtained from each of the ambulatory care clinics. The nature and purpose of the study were explained to all potential subjects, and 58 written informed consent was obtained prior to enrollment in the study. A copy of the consent form is located in Appendix F. Minorities and women were not excluded from this research. The percentage of minorities and women in this study were reflective of the percentages seen in cardiology practices in southwestern Idaho. The sample was composed of Anglo Americans. One Hispanic American male was referred to the study, but he was ineligible because he was younger than 65. Fewer women than men were enrolled in the study. More women than men were screened and found to be ineligible because they were too young, had LVEF greater than 40% or no measured L VEF, or had severe comorbidity such as chronic lung or kidney disease. Inclusion and exclusion criteria were necessary in order to isolate the variable of interest: fatigue. The risk to subjects participating in the study was low. Subjects volunteered their time for an interview that took 35 to 45 minutes. The task of filling out the questionnaire may have led to fatigue; however, no subject reported questionnaire­related fatigue. The risk of subject burden was minimized by administering the questionnaire by interview, selecting short scales, and avoiding redundant questions when possible. All subjects were able to tolerate a 45-minute session responding to the questionnaire. No subject admitted to tiredness that prevented him or her from continuing the questionnaire until completion. One subject talked excessively and, therefore, was unable to complete the PANAS during the interview time. Consequently, he was left a stamped envelope to mail at a later date. Another subject was unable to fill out the LIhFE independently. The potential benefits gained in this research exceed the minimal risk to subjects. 59 Confidentiality was protected through the use of a code number on the questionnaires. Subjects were told that they would not be identified by name, including other identifying data, in any published reports of this research. In addition, they were told that their questionnaires or responses would not be shared with their physicians, care providers, or family members. Raw data and consent forms were kept in a locked file. Procedures for Data Analysis Preliminary Analysis I completed the data entry in order to reduce variations incurred by multiple persons inputting information. Prior to data analysis, 51 % of the cases were randomly selected, and data entry was hand-checked against the raw data. The predetermined, acceptable data entry error rate was less than 1 %. The actual data entry error rate was 0.65 %, and all detected errors were corrected. Frequencies of all variables were assessed for outliers or unusual values and were compared with the raw data to look for coding or data-entry errors, with subsequent corrections made for any detected errors. Missing Data All missing data were examined to determine if a random or systematic pattern was present. For missing values within a scale, mean substitution was 60 employed. If a scale was missing, pairwise deletion necessitated dropping that case from the analysis for the missing value. There were five missing items within a scale, and mean substitution was used. One case was missing two responses on the POMS and a single response on the PANAS. Another case was missing two responses on the LIhFE. One case was missing the entire LIhFE; this case was dropped in any analysis in which this scale was used. Missing data were less than 0.4%, minimizing bias related to missing data. Descriptive Analysis Descriptive statistics were computed for all variables using SPSS for Windows (Norusis, 1997). Distributions of continuous variables were assessed for normality. The significance of results was determined by an alpha of < 0.05. Internal consistency reliability for the sample was established for all multiitem scales and subscales. The sample was described based on demographic and clinical variables. The intensity of fatigue was measured using the summed score on the POMS-F, ranging from 5 to 25, with higher numbers indicating higher fatigue. The intensity of fatigue based on the POMS-F was related to the VAS-F score, which was a global measure of fatigue collected concurrently. The score on the V AS-F was expressed in millimeters, with higher values indicating more intense fatigue. Simple correlations between the POMS-F and the VAS-F scores were performed to assess construct validity. The PO MS-F and V AS-F had a moderate positive and significant correlation (r = .52, P < .001), providing adequate 61 support for validity of the POMS-F. The prevalence of fatigue in this sample was determined using percentages. Measures of central tendency were used to describe intensity of fatigue. Demographic and clinical variables for subjects with high and low fatigue were explored. Independent 1 tests were conducted to test for differences in the dependent variable: fatigue by gender. Nonparametric tests were conducted on variables with the nominal level of measurement and when the sample size was small (Pett, 1997). Scores on the HFFSI were used to obtain the MET level for each subject and also were used to measure self-perceived functional status. Scoring of the HFFSI was completed by computing the average of the three highest MET levels assigned to activities endorsed with yes or yes. but slowly. A second rater independently scored the HFFSI, with a 98% agreement. The HFFSI also yielded information about what symptoms limited physical activities. The frequency for each of the major symptoms, including "fatigue afterwards," limiting physical activities was determined for the activity "waIking upstairs or uphill." Comparisons were made with results from younger individuals with advanced heart failure awaiting heart transplantation (Dracup et aI., 1992). Total and subscale scores were computed for the LIhFE. Differences in LIhFE scores by demographic variables were sought to describe the consequence of the illness representation. Percentages were used to describe high and low areas of disruption in this sample. A total score for the LIhFE was calculated, with the 62 deletion of question 13 ("making you tired, fatigued, and low on energy"). Then differences in the LlhFE between the high- and low-fatigue group were determined using an independent ! test. The relationships among demographic and clinical variables, self-perceived functional status, and intensity of fatigue were described using Pearson product­moment correlations. Because there was little relationship between fatigue and the independent variables identified based on the literature, correlations were computed among fatigue and symptom severity, perceived health, satisfaction with life, trait­negative affectivity, nominal marital status, and the LlhFE. Scatterplots were examined to determine if relationships between the dependent variable of fatigue and the independent variables were linear. No curvilinear relationships were detected; thus, linearity assumptions were met for multiple linear regression procedures. Hierarchical multiple regression was used to determine the combination of variables that predicts fatigue. The hierarchical regression method was selected to control the order that variables entered the equation independent of statistical criteria (Tabachnick & Fidell, 1989). The selection of independent variables was based on the strength of association with the intensity of fatigue in variables theoretically linked to fatigue. Trait-negative affectivity and the severity of disease (NYHA classification) were entered fIrst to control for these confounding variables. Following several multiple linear regression solutions, the equation that identified the set of variables that explained the highest variance of fatigue in older 63 adults with CHF was selected. Testing Assunlptions of Multiple Regression The visual inspection of the residual scatterplots was conducted to test for violations of statistical assumptions. Because the residuals were not normally distributed, the dependent variable (POMS-F) was transformed using the square­root transformation (Tabachnick & Fidell, 1989). The distribution of the transformed variable (square-root transformed POMS-F) was normal. Subsequent analysis using hierarchical multiple regression was conducted using the square-root transformed POMS-F as the dependent variable. The residuals were normally distributed; however, problems continued with heteroscedasticity on the scatterplots. The lack of the variance of residuals for high-predicted values indicated that the regression equation may not be a good predictor at higher levels of fatigue. In addition, data were examined for multicollinearity. Correlations among variables were less than .80. Testing for multicollinearity and singularity revealed no violations in assumptions (Hair et aI., 1995). CHAPTER IV RESULTS This chapter includes a description of the sample and the results of the data analysis performed to answer the research questions. Findings not directly related to the research questions that increase the understanding of the correlates of fatigue are also presented. Statistical analysis of quantitative data include Pearson product­moment correlation, independent! test, and multiple regression. Nonparametric tests, including the Mann-Whitney, Kruskal-Wallis one-way analysis of variance (ANOVA), chi-square test of association, and phi coefficient, were employed when violations in statistical assumptions occurred. SPSS for Windows was used to perform the statistical analysis following the procedures outlined in Chapter III (Norusis, 1997). Significant results were obtained when the 12 value was less than the prestated ex level of .05. Sample Sixty-one individuals diagnosed with CHF and documented left ventricular systolic dysfunction were invited to participate in the study. Five individuals declined to participate, and one was not enrolled because of dementia. Fifty-five subjects were enrolled between December 1998 and September 1999. One enrolled subject was dropped from the study because L VEF was greater than 40 % , indicating CHF secondary to diastolic dysfunction. Another enrolled subject was found to be an extreme univariate and multivariate outlier. Consequently, a decision was made to drop him from the study prior to data analysis. The final sample size was 53 subjects. Subjects were predominantly Anglo American (100 % ), male (68 % ), married (64%), and retired (85%). All subjects were outpatients and living at home, and their CHF was regarded as compensated with a stable medication regimen. Most subjects were interviewed at their homes, and questionnaires were completed in a single meeting. Five subjects were interviewed at their physicians' offices. One subject, who was hard of hearing, chose to take the questionnaire home to complete and then mailed it back to me. Demographic Data The final sample of 53 consisted of 36 men and 17 women, with a mean age of 77 years ranging from 65 to 91. Table 1 presents the demographic characteristics of the sample. Thirty-four individuals were married, 15 were widowed, 2 were divorced, 1 was separated, and 1 was not married but living as married. Marital status was later collapsed into married and not married, with 35 married and 18 not married. Twenty-six individuals had achieved an education beyond high school, 7 had graduated from college, and 4 had completed postgraduate work. Eight individuals were employed, 3 full time and 5 part time. Most individuals (85%) were retired; however, within the retired group, 1 also reported being disabled and 2 reported being homemakers. Nine individuals lived 65 66 Table 1 Summary of Sample Characteristics Variable !! Percent Gender Male 36 68.0 Female 17 32.0 Marital status Married 34 64.0 Separated 1 2.0 Widowed 15 28.0 Divorced 2 4.0 Living as married 1 2.0 Education ~ High school 27 51.0 > High school 26 49.0 Employment Full time 3 6.0 Part time 5 9.0 Retired 42 85.0 Living alone 9 17.0 Caregiver 5 9.0 Urban residence 31 58.0 Note. N = 53. 67 alone. Five of the individuals who did not live alone were the caregivers for their spouses. Thirty-one (58 %) individuals lived within the city limits, and the remaining 22 (42 %) lived in a rural residence. Clinical Data The clinical data are summarized in Table 2. Subjects had lived with CHF for an average of 37 months, ranging from a minimum of 6 months to a maximum of 198 months. The mean L VEF was 30.5%, ranging from 13 % to 40 %. The majority of the sample (91 %) was in NYHA class II or class III; that is, they had symptoms (dyspnea) with ordinary or less-than-ordinary activities. Most (72 %) of the subjects had CHF because of ischemic heart disease; however, 8 (15%) had dilated nonischemic cardiomyopathy. Eight of the individuals with ischemic heart disease reported angina requiring nitroglycerin at least once a week. The subjects had an average of 2.2 (SD = 1.1) chronic diseases in addition to CHF. A history of hypertension was the most common comorbidity and was present in 28 (53 %) individuals. In 5 cases, hypertension was identified as the cause of CHF. Seventeen (32 %) individuals had a recorded blood pressure of more than 140 systolic at their last clinic visit. An S3 gallop, a clinical sign of CHF, was recorded in the clinic notes in 16 (30%) individuals. Atrial fibrillation, a common arrhythmia in CHF, was present in 14 (26 %) individuals. The mean hemoglobin was 13.7 (SD = 1.7), and the mean hematocrit was 40.9 (SD = 5.1) in the subgroup who had laboratory results in the medical record (IL = 40). Table 2 Sun1mary of Clinical Variables Variable n Percent M SD Duration of CHF 37.1 40.2 (months) L VEF (percent) 30.5 7.0 NYHA class I 2 3.7 NYHA class II 30 56.6 NYHA class III 18 34.0 NYHA class IV 3 5.7 Cause of CHF ischemic heart disease 38 72.0 hypertension 5 9.0 valvular disease 1 2.0 dilated cardiomyopathy 8 15.0 other 1 2.0 Angina present 8 15.0 Atrial fibrillation present 14 26.0 S3 Gallop present 16 30.0 Hemoglobin (n = 40) 13.7 1.7 Hematocrit (n = 39) 40.9 5.1 Number of comorbidities 2.2 1.1 History of hypertension 28 53.0 Note. N = 53. NYHA class = New York Heart Association classification and L VEF = left ventricular ejection fraction. 68 69 The mean number of prescribed daily medications was 7, ranging from 2 to 15. Women took significantly more prescribed medications than men, 1(52) = 2.05, R < .05. The mean number of CHF medications (maximum of four) was 2.8 (SD = 1.1). Angiotensin converting enzyme inhibitors were prescribed for 85 % of the sample, diuretics for 87%, digoxin for 70%, and beta blockers for 40%. Twenty-five percent of the sample were taking carvedilol, a nonselective beta blocker prescribed for CHF. Independent! tests showed no significant difference for fatigue in individuals for whom a class of CHF medication is prescribed compared to a class not prescribed, 1(52) = .44, R > .05. Specifically, no difference was found for fatigue in individuals prescribed beta blockers compared to those not prescribed beta blockers, 1(52) = .26, R > .05. Adherence to the prescribed treatments and medications is depicted in Table 3. Adherence to medication regimen was high, with 94 % reported taking 100% of their medications during the past week. Performing daily weights had the lowest adherence. Seventy-five percent of the sample were encouraged by their physicians or nurses to follow a regular exercise program, and 53 % performed regular exercise at least three times a week. Three of the regular exercisers were enrolled in a cardiac rehabilitation program. The most common form of exercise performed was walking. Subjects who had exerted themselves during the past week (!l = 40) rated the intensity of their exercise as a mean of 3.7 (SD = 1.4), indicating somewhat strong on the 13-point Borg scale of perceived exertion. 70 Table 3 Adherence to Prescribed Treatments and Medications for Chronic Heart Failure Variable !! Percent Take 100 % of prescribed medications 50 94.0 Follow sodium-restricted diet 40 75.0 Perform daily weights 18 34.0 Told "should» exercise regularly 40 75.0 Exercise at least three times a week 28 53.0 Enrolled in cardiac rehabilitation program 3 6.0 Note. N = 53. The exercise group (n = 28) had a mean fatigue score on the PO MS-F of 10.8 (SD = 3.3), and the nonexercise group (n = 25) had a mean fatigue score of 12.4 (SD = 4.1). No significant difference was found in fatigue by exercise, 1(51) = 1.7, I! > .05. Analysis of covariance (ANCOVA) was used to control for trait-negative affectivity, and no difference in fatigue was found between the exercise group and the nonexercise group, 1:(2,50) = .419, I! > .05. Environmental Variables Data were collected through four seasons, with the majority (77 %) of interviews completed during winter and spring. Most (79%) of the interviews took place on Tuesday or Friday throughout the day; only 3 interviews were completed in the evening. Fifty-one percent of the interviews were scheduled between 1 :00 71 p.m. and 3:00 p.m. The weather was generally sunny; however, for 11 interviews, it was cloudy, 4 rainy and 3 snowy. High and low temperatures for the interview day were recorded from the National Weather Service. Temperatures varied depending on the season, with mean high and low temperatures of 60 degrees and 38 degrees Fahrenheit, respectively. Vigor, as measured with the POMS-V, was highest on rainy and snowy days and lowest on cloudy days. However, this difference was not statistically significant. Kruskal-Wallis one-way ANOVA was employed because of uneven and small group sizes. No significant differences were found in fatigue by weather pattern, X2 = 3.35, df = 3, :Q > .05. Research Questions The research questions guided the organization and presentation of the results. 1. What are the prevalence and intensity of fatigue in older men and women with CHF secondary to left ventricular systolic dysfunction? The prevalence and intensity of fatigue were determined for the sample utilizing two measures of fatigue: (a) POMS-F and (b) VAS-F. In addition, measuring vigor may contribute to the understanding of fatigue. The mean fatigue measured on the POMS-F was 11.5 (SD = 3.8), with the minimum fatigue of 5 and the maximum fatigue of 20. The average score endorsed on the five fatigue items was 2.3, indicating a value above a little on the scale. The prevalence of fatigue in the sample was 96 %, with 51 subjects reporting scores greater than 5. Two subjects, both men, had no fatigue as measured by the POMS-F, marking not 72 at all on all five fatigue items. The distribution of fatigue scores on the POMS-F was fairly uniform, with a bimodal pattern at 9 and 13. The shape of the distribution was similar between men and women, except for a larger variation of scores in men. The POMS-F was positively correlated with both VAS-F and VAS-W ([ = .52, 12 < .001; r = .32, 12 < .05, respectively), and was inversely correlated with the POMS-V ([ = -.43, 12 = .001). The expected direction and magnitude of associations supported the validity of the POMS-F in this sample. Tables 4 and 5 present the correlation coefficients between fatigue measures and selected study variables. The V AS-F is a global single-item measure of fatigue and was administered concurrently within the same time frame of the past week. The mean score on the VAS-F was 51.8 (SO = 19.3), with a minimum score of 7 and a maximum score of 87. According to the V AS-F, the prevalence of fatigue was 100% in this sample. The lowest score was 7, with 0 indicating no fatigue. Thirty-four (64%) subjects scored at 50 millimeters or higher, suggesting clinically significant levels of fatigue during the past week. The distribution of scores on the V AS-F was near normal but was positively skewed. Again, a larger spread of values was observed on the box plots for men compared to women. Vigor scores were assessed with 'the POMS-V and mean vigor was 12.9 (SO = 3.4), with a minimum score of 5 and a maximum score of 21. The average response on the five vigor items was 2.6, falling between a little and moderately. One subject endorsed not at all for all five vigor items. The distribution of vigor Table 4 Pearson Product-Moment Correlation Coefficients Between Fatigue Measures and Selected Variables variable 1 2 3 4 5 6 7 8 9 10 1 Fatigue (POMS-F) .52** -.43** - .12 .30* .12 .54** .07 -.04 .32* 2 Fatigue (VAS-F) -.22 -.05 .12 -.00 .50** -.27 .30 .48** 3 Vigor (POMS-V) .24 -.37** -.10 -.35* -.08 .03 -.27 4 Functional status -.32* -.31 - .14 -.37** .16 -.14 (METs) 5 NYHA class -.05 .54** -.05 -.02 .20 6 LVEF .11 .24 -.14 .06 7 Disruption (LlhFE) .01 -.07 .66** 8 Age -.46** -.00 9 Duration of CHF .05 10 Weakness (VAS-W) Note. N = 53. METs = Score on Heart Failure Functional Status Inventory (HFFSI) indicating maximal metabolic equivalent, NYHA class = New York Heart Association classification, L VEF = left ventricular ejection fraction, and LIhFE = Minnesota Living with Heart Failure questionnaire. *12 < .05. **12 < .001. .....:J VJ Table 5 Point Biserial Correlation Coefficients Between Fatigue Measures and Selected Categorical Variables variable 1 Fatigue (POMS-F) 2 Fatigue (VAS-F) 3 Vigor (POMS-V) 4 Gender (1 = female) 5 Marital status (1 = married) 6 Education (1 = beyond high school) 7 Employment (1 = employed) 8 Atrial fibrillation (1 = present) 9 Angina (1 = present) 10 Age attribution (1 = yes) Note. N = 53. *l! < .05. **l! < .001. 1 2 3 4 -.04 .17 -.24 5 .32* .09 .09 6 -.09 .03 .17 7 8 -.16 -.08 -.07 -.09 .46** -.05 9 .09 -.09 -.16 10 .29* .40** .09 .....:t ~ 75 scores was more normal than of fatigue scores, with a bimodal pattern again noted. Men's vigor scores had greater variation than women's scores, and women's scores were restricted with fewer scores at the higher values compared to men's scores. Table 6 compares the mean values of fatigue and vigor between men and women. Independent 1 tests were conducted, and no statistically significant differences were found in fatigue and vigor scores between men and women, 1(51) = .26, R > .05. The lack of significant differences was confmned when ANCOVA was employed to control for trait-negative affectivity and NYHA classification. Because of unequal group size and violations of normal distribution, a nonparametric test (Mann-Whitney) was performed, with results supporting the parametric tests. Two outliers were identified in this sample for fatigue by gender. One of the outliers was a multivariate outlier determined by a Mahalanobis distance exceeding the critical value of 22.46 (df = 6, R < .001) and univariate extreme scores greater than 2.5 standard deviations on the POMS-F, VAS-F, symptom severity, and trait-negative affectivity (Hair et al., 1995). A decision was made to delete this subject from the analysis because of the influence that extreme outliers have on multiple regression solutions (Tabachnick & Fidell, 1989). The second outlier was retained in the analysis because this subject was not a multivariate outlier, with the extreme score on the POMS-F being consistent with the situation. In addition to the outlier analysis, it may be useful to know more about the 2 individuals who reported no fatigue on the POMS-F. Both subjects were male, Table 6 Measures of Central Tendency for Fatigue and Vigor by Gender Men (n = 36) Women (n = 17) Total (N = 53) Variable M SD Range M SD Range M SD Range POMS-F 11.6 3.8 5-20 11.4 3.9 7-20 11.5 3.8 5-20 VAS-F 49.6 20.1 7-87 56.4 17.1 29-81 51.8 19.3 7-87 POMS-V 13.5 3.6 5-21 11.8 2.7 7-15 12.9 3.4 5-21 Note. N = 53. POMS-F = fatigue subscale with possible range of 5 to 25, higher scores = high fatigue; VAS-F = visual analogue scale for fatigue ranging from 0 to 100 millimeters; POMS-V = vigor subscale with possible range of 5 to 25, higher scores = high vigor. No significant difference in fatigue measures or vigor by gender, I! > .05. "-l 0\ 77 75- and 79-years-old. The 79-year-old was employed full time and had a POMS-V score of 21. The 75-year-old was enrolled in cardiac rehabilitation, had recently undergone cardiac bypass and valve surgery, and had a POMS-V score of 15. Both subjects had high MET levels of 7.83 and low trait-negative affectivity. In addition, one subject scored a 5 on the POMS-V, which is the lowest score possible, indicating not at all to all five vigor adjectives. This subject was a 74- year-old male who had undergone two cardiac bypass surgeries several years ago. He rated his health as good, exercised regularly, and had a MET level of 5. In conclusion, the prevalence of fatigue was 96 % in this sample, and the intensity of fatigue was reflected by a mean POMS-F of 11.5 (SD = 3.8). Global fatigue was assessed using the V AS-F. The results supported the validity of the POMS-F as a fatigue measure in this sample. No statistically significant differences were found in fatigue or vigor between men and women. 2. What is the relationship of fatigue to self-perceived functional status in older men and women with CHF secondary to left ventricular systolic dysfunction? Subjects reported a mean MET level of 5.88 (SD = 1.5) on the HFFSI. See Table 7 for MET levels for men and women. A significant difference was found for MET levels between men and women, 1(52) = 2.43, J2 < .05. Women reported having more limitations in performing high-exertional activi