Online Coverage from the
70th Annual Scientific Sessions
of the American Heart Association
November 9 - November 12, 1997
© 1997 Medscape, Inc.

In-Hospital Mortality is Higher in AMI Patients Enrolled in an HMO

Speaker: Paul N. Casale, MD
Reporter: Carlos S. Ince, MD


The healthcare system in the US has undergone dramatic changes in the last decade. There has been a concerted effort to control the cost of healthcare, and a number of techniques have been initiated to attain this goal. In this effort, critical pathways have been established to cost-effectively manage a variety of patient care issues by standardizing service. Health maintenance organizations (HMOs) control their costs by using a number of strategies, including limiting admissions and referrals, and reducing utilization rates of procedures. There is concern that these restrictive guidelines may adversely effect clinical outcomes.

Study Goal

The intent of this analysis was to compare the clinical outcomes base d on insurance type (HMO versus fee-for-service) after controlling for 12 patient characteristics predictive of in-hospital mortality, as well as for physician specialty (cardiology versus primary care providers), hospital type (those with and without the ability to perform bypass surgery), and individual hospital variability.

Dr. Paul Casale and colleagues of Lancaster Heart Foundation in Lancaster, Pennsylvania, analyzed 3999 acute myocardial infarction (AMI) patients under the age of 65 who were admitted to hospitals in southeastern Pennsylvania in 1993. These patients were a subset of those taking part in The Pennsylvania Health Care Cost Containment Council (PHCCCC) analysis of 20 clinical variables in patients with AMI. That study aimed to identify independent predictors of mortality. Of the 20 patient characteristics examined, 12 variables were found to be significant predictors -- the same 12 that were controlled for in this trial.

Study Population

The analysis was conducted on 1034 HMO patients and 2965 fee-for-service patients. Most data were collected from the clinical database, and additional data were extracted from patient records, when appropriate. Fee-for-service patients were slightly older (54 versus 53 years of age), were more likely to be male (78% versus 75%), and were more likely to have cardiac dysrhythmias or conduction abnormalities. The groups were similar with respect to the percentage of comorbidities and prognostic factors, including cardiogenic shock, cardiomyopathy, diabetes mellitus, hemodialysis, renal failure, infarct location, and prior history of coronary artery bypass surgery.

HMO Patients Fared Worse

Multivariate analysis revealed that in-hospital mortality was significantly higher for HMO patients than in fee-for-service patients (odds ratio 2.16, 95% CI; 1.24 to 3.76) after adjusting for physician specialty, hospital type, and individual hospital. Univariate analysis on procedure utilization demonstrated that fee-for-service patients were more likely to undergo cardiac catheterization (79% versus 70%, P<0.001) and percutaneous transluminal coronary angioplasty (33% versus 27%, P=0.007). There was no difference in the rates of bypass surgery in the groups (15.7% versus 15.6%). When adjusted for patient risk, physician specialty, and hospital type, HMO patients were less likely to have a cardiac catheterization (odds ratio 0.65, 95% CI; 0.52 to 0.82).


Based on these data, enrollment in an HMO is an independent predictor of in-hospital mortality in those patients presenting with an AMI. HMO patients are less likely than fee-for-service patients to undergo cardiac catheterization and angioplasty after acute infarct. Further studies are needed to determine the specific policies of managed care organizations which may be contributing to adverse clinical outcomes.

AHA Scientific Sessions

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  1. Kreindel S, Rosetti R, Goldberg R, et al:
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    Arch Intern Med 157(7):758-62, 1997 Apr 14.
  2. Every NR, Fihn SD, Maynard C, et al:
    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.
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  3. Pearson SD, Lee TH, Lindsey E, et al:
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