Hospitals that perform fewer cardiac bypass operations don't have more deaths following the procedure than hospitals that handle more of the procedures, according to a study. Conventional wisdom has assumed that hospitals that do more cardiac bypass operations have better results, with fewer patient deaths. For the study, researchers collected data on 108,087,386 people admitted to U.S. hospitals from 1988 to 2003. The authors say the findings show that using death rates after cardiac bypass surgery may no longer be an accurate gauge of the quality of care.