RESOURCE UTILIZATION IN TREATMENT OF ACUTE MYOCARDIAL-INFARCTION - STAFF-MODEL HEALTH MAINTENANCE ORGANIZATION VERSUS FEE-FOR-SERVICE HOSPITALS

Objectives. This study sought to compare the use of invasive procedure s and length of stay for patients admitted with acute myocardial infar ction to health maintenance organization (HMO) and fee-for-service hos pitals. Background. The HMOs have reduced costs compared with fee-for service systems by reducing discretionary admissions and decreasing ho spital length of stay. It has not been established whether staff model HMO hospitals also reduce the rate of procedure utilization. Methods. Using data from a retrospective cohort, we performed univariate and m ultivariate comparisons of the use of cardiac procedures, length of st ay and hospital mortality in 998 patients admitted to two staff-model HMO hospitals and 7,036 patients admitted to 13 fee-for service hospit als between January 1988 and December 1992. Results. The odds of under going coronary angiography were 1.5 times as great for patients admitt ed to fee-for-service hospitals than for those admitted to HMO hospita ls (odds ratio 1.5, 95% confidence interval [CI] 1.3 to 1.9). Similarl y, the odds of undergoing coronary revascularization were two times gr eater in fee-for service hospitals (odds ratio 2.0, 95% CI 1.6 to 2.5) . However, higher utilization was strongly associated with the greater avail ability of on-site cardiac catheterization facilities in fee-fo r-service hospitals. The length of hospital stay, by contrast, was sim ilar to 1 day shorter in the fee-for service cohort (7.3 vs. 8.0 days, p < 0.05). Conclusions. Physicians in staff model HMO hospitals use f ewer invasive procedures and longer lengths of stay to treat patients with acute myocardial infarction than physicians in fee-for service ho spitals. This finding, however, appears to be associated with the lack of on site catheterization facilities at HMO hospitals.