Coronary Artery Bypass Graft Surgery Statistics

The importance of program service volumes in health service development and operations, and their connection to certificate of need (CON) regulation, has been demonstrated recently with the publication of a nationwide study of Medicare patients that documents statistically significant lower mortality rates for coronary artery bypass graft (CABG) surgery patients receiving treatment in programs in states that regulate open-heart surgery under CON.

The authors note most CON studies have focused on whether CON has affected capital investment and health care costs, and that few have examined directly the relationship between CON regulation and quality. The study was designed to “compare risk-adjusted mortality and hospital volumes for CABG surgery in states with and without certificate of need regulation.”

The study analyzed the experience of more than 900,000 Medicare patients 65 years of age or older, who underwent CABG surgery in the six-year period between 1994 and 1999. They received care in a total of more than 1,000 US hospitals. States were divided into those with continuous CON regulation (27 states), those that had no CON regulation during the study period (18 states), and those that terminated or reinstated CON during the period (6 states). The analysis found that risk-adjusted mortality rates were 22% higher in states without CON regulation than in states with regulation. A statistically significant difference was observed in each of the six years of the study period. The study also determined that:     

•States with CON regulation had average program volumes 84% higher than those without regulation,

• States that recently terminated CON regulation had large decreases in average CABG surgery volumes, and

•In states without CON regulation, the percentage of patients that had surgery in low volume programs was three times higher than in states with CON regulation.

In addition, the data showed that the repeal of CON regulation resulted in a tripling of the percentage of patients having CABG surgery in low-volume hospitals. This study documents the positive role of planning and CON regulation in assuring higher average CABG surgery program volumes and the resulting lower risk-adjusted mortality rates.

It is noteworthy that this study also found that a higher percentage of those having CABG surgery in states without CON regulation underwent diagnostic cardiac catheterization or percutaneous transluminal coronary angioplasty (PTCA) on the same day as surgery. This suggests that the treatment outcomes for these procedures may be worse, for the same reason that CABG surgery mortality rates are worse, in states without CON regulation. The researchers observe “the higher incidence of cardiac catheterization and PTCA on the same day as CABG surgery may reflect higher complication rates for those procedures, rather than greater patient pre-surgical risk.”

State specific data for the six years covered by the study can be seen by clicking on the state of interest.