Cover: Explaining Variations in Hospital Death Rates

Explaining Variations in Hospital Death Rates

Randomness, Severity of Illness, Quality of Care

Published 1991

by Rolla Edward Park, Robert H. Brook, Jacqueline Kosecoff, Joan Keesey, Lisa V. Rubenstein, Emmett B. Keeler, Katherine L. Kahn, William H. Rogers, Mark R. Chassin


Download eBook for Free

FormatFile SizeNotes
PDF file 3.8 MB

Use Adobe Acrobat Reader version 10 or higher for the best experience.


Purchase Print Copy

 Format Price
Add to Cart Paperback108 pages $30.00

Hospital death rates vary markedly, even for the same disease. The authors studied a representative sample of 1,126 congestive heart failure patients and 1,150 acute myocardial infarction patients in hospitals with unexpectedly high disease-specific death rates (targeted hospitals) vs. all other (untargeted) hospitals in California, Illinois, Minnesota, and New York, using both inpatient deaths and deaths within 30 days of admission. Death rates in targeted hospitals were 5.0 to 10.9 higher per 100 admissions than in untargeted hospitals. However, 56 to 82 percent of the excess could result from random binomial variation, even if all hospitals provided the same quality of care to the same age/sex/race mix of patients. The authors measured severity of illness and quality of care using detailed medical records abstracts; at the individual patient level, higher severity and lower quality were both associated with higher probability of death. However, they found only small and insignificant differences in quality between targeted and untargeted hospitals; even at a 95 percent confidence bound on the estimated difference in quality, quality differences could explain only 0.3 or fewer of the excess deaths per 100 admissions in targeted hospitals. Severity differences were also small for hospitals treating congestive heart failure patients. For myocardial infarction patients, however, severity differences explained up to 2.8 excess deaths per 100 admissions in targeted hospitals. There is some evidence that targeting hospitals with consistently high death rates over periods longer than one year may better identify potential quality problems.

This report is part of the RAND report series. The report was a product of RAND from 1948 to 1993 that represented the principal publication documenting and transmitting RAND's major research findings and final research.

This document and trademark(s) contained herein are protected by law. This representation of RAND intellectual property is provided for noncommercial use only. Unauthorized posting of this publication online is prohibited; linking directly to this product page is encouraged. Permission is required from RAND to reproduce, or reuse in another form, any of its research documents for commercial purposes. For information on reprint and reuse permissions, please visit

RAND is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.