Adjusted mortality of patients undergoing coronary bypass surgery by quartile of hospital volume and count of missed quality measures. A strong association between the number of quality measures missed and mortality across all quartiles of volume is observed, with mortality similar across quartiles of hospital case volume if no quality measures are missed. Models adjusted for age, gender, DRG predicted mortality, congestive heart failure, hypertension, neurological disorders, diabetes with complications, renal failure, coagulopathy, deficiency anemia, and whether or not an internal mammary graft was used during the procedure, the volume and number of missed quality measures as well as for the interaction between volume and number of missed quality measures.