Received 7 August 2006; received in revised form 19 July 2007; accepted 19 July 2007. published online 18 October 2007.
Background
Patients considering where to have surgery may reasonably believe that their chances of survival are highest at hospitals whose reported operative mortality is zero. We sought to determine if hospitals with zero mortality over 3 years also have lower than average mortality in the subsequent year.
Study Design
We obtained national Medicare data on five operations with high operative mortality (> 4.0%): coronary artery bypass grafting, abdominal aortic aneurysm repair, and resections for colon, lung, and pancreatic cancer. For each procedure, we defined zero mortality hospitals as those with no inpatient or 30-day deaths during the 3-year period 1997 to 1999. To determine whether these hospitals actually have lower mortality than other hospitals, we compared their mortality during the next year (2000) with the mortality at all other hospitals.
Results
For four procedures, operative mortality in zero mortality hospitals in the subsequent year was no different than that in other hospitals: abdominal aortic aneurysm repair (6.3% zero mortality hospitals versus 5.8% other hospitals; (adjusted relative risk [RR]=1.09; 95% CI 0.92 to 1.29); lobectomy for lung cancer (5.1% versus 5.3%; RR=0.96; 95% CI 0.80 to 1.15); colon cancer resection (6.0% versus 6.6%; RR=0.91; 95% CI 0.80 to 1.03); and coronary artery bypass surgery (4.0% versus 5.0%; RR=0.81; 95% CI 0.61 to 1.04). In the case of pancreatic cancer resection, zero mortality hospitals had substantially higher mortality than other hospitals (11.2% versus 8.7%; RR=1.29; 95% CI 1.04 to 1.59).
Conclusions
Paradoxically, hospitals with a history of zero mortality subsequently experience mortality rates that are the same or higher than those of other hospitals. Patients considering surgery should not consider a reported mortality of zero as being a reliable indicator of future performance.
aVA Outcomes Group, Department of Veterans Affairs Medical Center, White River Junction, VT
bCenter for the Evaluative Clinical Sciences, Dartmouth Medical School, Hanover, NH
cMichigan Surgical Collaborative for Outcomes Research and Evaluation (M-SCORE), Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI.
Correspondence address: Dr Justin Dimick, VA Outcomes Group 111B, VA Medical Center, 215 N Main St, White River Junction, VT 05009.
Competing Interests Declared: None.
Dr Dimick was supported by a Veterans Affairs Special Fellowship Program in Outcomes Research. This study was also supported by a Research Enhancement Award from the Department of Veterans Affairs (REA 03–098).
The views expressed herein do not necessarily represent the views of the Department of Veterans Affairs or the federal government.
ABSTRACT