Author + information
- Received July 29, 1994
- Revision received March 22, 1995
- Accepted March 31, 1995
- Published online August 1, 1995.
- Nathan R. Every, MD, MPH1,
- Stephan D. Fihn, MD, MPH,
- Charles Maynard, PhD,
- Jenny S. Martin, RN and
- W.Douglas Weaver, MD, FACC
- ↵1Address for correspondence: Dr. Nathan R. Every, MITI Coordinating Center, 1910 Fairview Avenue East, Suite 205, Seattle, Washington 98102.
Objectives. This study sought to compare the use of invasive procedures and length of stay for patients admitted with acute myocardial infarction to health maintenance organization (HMO) and fee-for-service hospitals.
Background. The HMOs have reduced costs compared with fee-for-service systems by reducing discretionary admissions and decreasing hospital 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 multivariate comparisons of the use of cardiac procedures, length of stay and hospital mortality in 998 patients admitted to two staff-model HMO hospitals and 7,036 patients admitted to 13 fee-for-service hospitals between January 1988 and December 1992.
Results. The odds of undergoing coronary angiography were 1.5 times as great for patients admitted to fee-for-service hospitals than for those admitted to HMO hospitals (odds ratio 1.5, 95% confidence interval [CI] 1.3 to 1.9). Similarly, the odds of undergoing coronary revascularization were two times greater in fee-for-service hospitals (odds ratio 2.0, 95% Cl 1.6 to 2.5). However, higher utilization was strongly associated with the greater availability of on-site cardiac catheterization facilities in fee-for-service hospitals. The length of hospital stay, by contrast, was ∼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 fewer invasive procedures and longer lengths of stay to treat patients with acute myocardial infarction than physicians in fee-for-service hospitals. This finding, however, appears to be associated with the lack of on-site catheterization facilities at HMO hospitals.
☆ This study was supported by Grant R01 HL38454 from the National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, and by an unrestricted grant from Genentech, Inc., South San Francisco, California.
- Received July 29, 1994.
- Revision received March 22, 1995.
- Accepted March 31, 1995.