title: Resource utilization in treatment of acute myocardial infarction: staff-model health maintenance organization versus fee-for-service hospitals. The MITI Investigators. Myocardial Infarction Triage and Intervention.
abstract: OBJECTIVE
  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% CI 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 approximately 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.
authors.affiliation: Northwest Health Services Research and Development Field Program, Seattle Veterans Affairs Medical Center, WA, USA.
authors.forename: N R
authors.initials: NR
authors.lastname: Every
authors.forename: S D
authors.initials: SD
authors.lastname: Fihn
authors.forename: C
authors.initials: C
authors.lastname: Maynard
authors.forename: J S
authors.initials: JS
authors.lastname: Martin
authors.forename: W D
authors.initials: WD
authors.lastname: Weaver
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D015986:Confounding Factors, Epidemiologic; D017023:Coronary Angiography / Q000191:economics / Q000706:statistics & numerical data*; D018588:Fee-for-Service Plans / Q000191:economics* / Q000706:statistics & numerical data; D005260:Female; D006279:Health Maintenance Organizations / Q000191:economics* / Q000706:statistics & numerical data; D006739:Hospital Administration / Q000191:economics*; D017052:Hospital Mortality; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D009204:Myocardial Revascularization / Q000191:economics / Q000706:statistics & numerical data*; D016017:Odds Ratio; D012189:Retrospective Studies; D014218:Triage; D014481:United States; D014861:Washington