A low-cost approach to prospective identification of impending high cost outcomes.

OBJECTIVES: The overall objective of this study was to define and evaluate patterns of use of medical services in the care of patients with chronic illness that represent circumstances which, if modified, might lead to reduction in risk of acute-level care. METHODS: This was a retrospective observational study. The study population consisted of Kaiser Permanente enrollees at four sites during January 1993 through June 1995, who were 20 to 64 years of age and had two of three chronic diseases (diabetes, circulatory disorders, obstructive pulmonary disorders). Using logistic regression, the effect of primary care visit patterns and therapeutically risky drug combinations on likelihood of hospital admission in a subsequent 3-month period is adjusted for age, gender, and disease state in the prior 12-month period. RESULTS: Enrollees with visits to three or more different primary care physicians were 46% more likely to be admitted than expected (P < 0.01) according to their age, gender, and disease state, and those with therapeutically risky drug combinations were 34% more likely to be admitted (P < 0.01). CONCLUSIONS: The risk adjustment models evaluated in this study defined care processes associated with increased risk of subsequent acute-level services. Those processes may represent nascent acute disease states or suboptimal organization of care delivery. The results of these models can be used to inform changes in organization and delivery of outpatient care that might improve patient outcomes.

A comparison of length of stay and costs for health maintenance organization and fee-for-service patients.

Enrollees of health maintenance organizations (HMOs) are less frequently hospitalized than are patients cared for by fee-for-service physicians. To determine if care provided to HMO and fee-for-service patient is different once they are hospitalized, we compared length of stay, total costs, and severity of illness for 617 HMO and fee-for-service patients hospitalized during the period 1983 through 1985 at a major teaching hospital. Severity was gauged in the following two ways: the Severity of Illness Index developed by Horn, and ratings by two physicians who were given all records from the first day of each patient's hospitalization. Length of stay was shorter and total costs were less for HMO patients in 7 of 11 diagnosis related groups. Using regression analysis to adjust for age, sex, emergency ward admission, diagnosis related group, and severity, we found that overall length of stay was 14% shorter for HMO patients than for fee-for-service patients (6.2 vs 5.3 days, P less than .01), whereas total costs were only 4% less ($4251 vs $4090, P greater than .2). These findings indicate that while patterns of utilization may vary by diagnosis related groups, HMO patients had shorter lengths of stay but comparable overall costs. Whether shorter lengths of stay represent greater efficiency, substitution of outpatient for inpatient care, or diminution in the quality of care is not clear.