Assessing the effect of adverse hospital events on the cost of hospitalization and other patient outcomes

It is estimated that in 1992 the United States spent 14% of its gross domestic product on health care. This level of health care spending is the highest in the world and almost twice as high as any other country. It is expected that 20% of the gross domestic product of the United States will be spent on health care by the year 2000. This has raised considerable interest in methods for health care cost containment. Assessing cost outcomes of medical care is one method of measuring and comparing the costs of medical care. Hospitals account for the largest share of health care spending. Unfortunately methods for linking detailed cost outcomes with hospital care are primitive at best. This study develops a methodology to link adverse effects of clinical care in the hospital with detailed cost outcomes. This study focusses on three adverse events that are common in hospital patients and are associated with large resource use. For this project a hospital information system known as HELP was used. This system is a comprehensive clinical information in operation at LDS Hospital where this study was performed. The HELP System is linked with an IBM Financial system. Patient hospitalizations are linked in both systems by a unique identifier, which allowed linking of clinical and financial information. The HELP system includes a variety of surveillance programs that detect various adverse events occurring in hospital patients including nosocomial surgical wound infections and urinary tract infections and adverse drug events. This study matched patients with each of these three adverse events to cohort patients base on sex, age, discharge diagnosis, severity of illness, and calendar year of discharge. Attributable differences in hospital length of stay and costs were compared using an attribution methodology. Over the period January 1, 1990 to August 1, 1992, a total of 1,552 case patients with these adverse events were matched to 17,747 cohort patients without these events. The mean attributable difference in length of stay between cases and matched cohorts for nosocomial surgical wound infections was 5.34 days (p < .00001). The mean attributable difference in hospital costs between the nosocomial surgical wound infection patients and the matched patients was $4,935 (p < .00001). The mean attributable difference in length of stay between the cases and matched cohorts for UTIs was 3.84 days (p< .00001). The mean attributable difference in hospital costs between the urinary tract infection patients and the matched patients was $3,803 (p<.00001). For adverse drug events the mean attributable difference in length of stay between these two groups was 1.94 days (p=.062). The mean attributable difference in hospital costs between the adverse drug event patients and the matched patients was $1,939 (p=.147). The total cost of all three adverse events at LDS Hospital in 1992 was $5,439,243, which accounted for over 3% of the hospital's annual budget.