Biobehavioral and Environmental Influences on Sleep in Children with Cancer

Disturbed sleep-wake patterns are prevalent in up to 40% of children with cancer; however, sources of sleep-wake pattern disturbances are not well understood. Light and noise disrupt sleep-wake patterns in intensive care settings. Cancer-related symptoms, including fatigue, may impair sleep. Individual temperament characteristics influence symptoms in acutely and chronically ill children. Polymorphisms in the dopamine D4 receptor gene and regulatory region of the serotonin transporter promoter gene are associated with behavioral variation and may influence the child's response to physiologic and environmental stimuli. The purpose of this multiple-case study was to examine sleep-wake patterns and the influences of environmental and biobehavioral factors on sleep-wake patterns among children with cancer. The UCSF Symptom Management Model was the conceptual framework. Participants were 15 school-age children with cancer receiving inpatient chemotherapy. Data were collected during an admission lasting 3 days or longer. Wrist actigraphs and sleep diaries measured sleep. A data logger and sound pressure level meter measured environmental variables. Fatigue was measured using Fatigue Scale: Child and Parent Versions. Temperament was measured using Carey Temperament Scales. Polymerase chain reaction was used to genotype polymorphisms. Data analysis included statistical and visual graphical analyses. Children with cancer slept less and had more fragmented sleep compared with age-related norms. A basic mixed linear model identified a significant main effect for epoch (F = 56.27, g < .01) on sleep minutes within a night shift. Main effects for sound (F = 50.87, p < .01) and light (F = 7.04, p < .01) on sleep minutes were present. A backwards multiple regression model contained five variables (sound, light, number of medications, pain, and nausea) Accounting;; for 57.4% of the variance in sleep minutes within each 2-hour epoch of a 12-hour night shift (F = 62.85, p < .01). Children with less predictable biologic cycles slept longer and had fewer awakenings. Children homozygous for short serotonin polymorphisms, associated with increased anxiety, had poorer sleep efficiency. Clinicians should seek opportunities to minimize nighttime disruptions. Research is warranted to develop and test interventions to promote sleep in the hospital and investigate the role of intraindividual factors on children's cancer-related symptoms.