Hospital report cards on coronary bypass surgery are more accurate when based on 2-year data
Research Activities, November 2010, No. 363
The public reporting of hospital outcomes data is becoming increasing popular, particularly with the availability of the Internet. Patients and their doctors can now find information on how hospitals do when it comes to various conditions and treatments. One area where these "mortality report cards" have become popular is for coronary artery bypass graft (CABG) surgery. However, these data may not be accurate for predicting subsequent hospital performance depending on how old the data are. A new study finds that patients and doctors can rely on risk-adjusted outcomes reports based on 2-year-old data for CABG surgery as a strong predictor of future hospital performance. However, mortality report cards based on 3-year-old data are not that useful when it comes to identifying low-performance hospitals.
Researchers looked at hospital mortality measures at 37 hospitals in New York State that perform CABG surgery. Patients and doctors can access such data from the State's health department Web site. At the moment, CABG mortality report cards are based either on 2- or 3-year old data. An observed-to-expected mortality rate (O-to-E ratio) was used to determine the association between a hospital's past quality ranking and its future performance. The subsequent performance of hospitals classified as low-performance in their 3-year-old report cards was no different than that of hospitals classified as average hospitals. Hospitals identified as high-quality using 3-year-old data had a subsequent O-to-E ratio that was 19.4 percent lower than intermediate-quality hospitals. At the same time, hospitals identified as low-quality hospitals based on 3-year-old data had subsequent O-to-E ratios nearly identical to intermediate-quality hospitals. On the other hand, high-quality hospitals identified by using 2-year-old data had O-to-E ratios that were 16.8 percent lower than intermediate-quality hospitals. Also, there was a 31.8 percent higher O-to-E ratio for low-quality hospitals compared with intermediate-quality hospitals.
Based on these findings, the researchers recommend that New York State base its CABG surgery mortality rates on 2-year-old data. The study was supported in part by the Agency for Healthcare Research and Quality (HS16737).
See "How well do hospital mortality rates reported in the New York State CABG report card predict subsequent hospital performance?" by Laurent G. Glance, M.D., Andrew W. Dick, Ph.D., Dana B. Mukamel, Ph.D., and others in the May 2010 Medical Care 48(5), pp. 466-471.