Association of past mortality rates on future hospital mortality

The relationship between hospital volume and patient outcomes has been extensively studied, and a hospital’s past procedure volume has been shown to predict mortality. The predictive value of a hospital’s past mortality rate is less well known, however.

The aim of this study by researchers from the University of California, San Diego; University of California, Irvine; and Harvard Medical School, Boston, was to determine whether a hospital’s high historical mortality rates would be associated with high future mortality rates for the same procedures.
Procedures included were abdominal aortic aneurysm repair, aortic valve replacement, and coronary artery bypass grafting. The analysis included 455,161 patients in a California inpatient database from 1998 to 2010.

Results showed that patients presenting to a hospital with a higher procedural past mortality rate had a 30% to 60% increased risk of death than if they had presented with the same condition to a hospital with a lower past mortality rate.

The findings emphasize the critical role of nonpatient factors in determining patient outcomes and the importance of recognizing the effects of health systems on individual patient outcomes, the researchers concluded.

—Coe T M, Wilson S E, Chang D C. Do past mortality rates predict future hospital mortality? Am J Surg. 2016;211(1):159-165.

http://www.americanjournalofsurgery.com/article/S0002-9610(15)00231-7/abstract