Statewide quality improvement initiatives and mortality after cardiac surgery

Background.-Recent reports from New York and northern New England claim that statewide quality improvement initiatives and outcome reporting are leading to decreased mortality following coronary artery bypass graft (CABG) surgery. Objective.-To compare trends in mortality after CABG surgery in Massachusetts (a state that has not instituted statewide outcome reporting) with the decreases reported from New York and northern New England. Design.-Surgical cohorts from 1990, 1992, and 1994 were used to evaluate the risk-adjusted mortality trend for Massachusetts. We present this trend along with the published trends from New York and northern New England. For comparison, we also present unadjusted Medicare mortality trends from Massachusetts, New York, northern New England, and the entire United States. Setting.-All 12 Massachusetts hospitals performing cardiac surgery (excluding a Veterans Affairs hospital). Patients and Data Sets.-Massachusetts administrative data were used to identify all patients undergoing isolated CABG surgery in 1990, 1992, and 1994. Main Outcome Measures.-Observed and risk-adjusted in-hospital mortality. Results.-Observed mortality rates in Massachusetts decreased from 4.7% in 1990 to 3.5% in 1992 and to 3.3% in 1994. The corresponding risk-adjusted mortality reductions for 1992 and 1994 (relative to 1990) were 35% and 42%, respectively. The mortality reduction seen in Massachusetts is comparable to the reductions seen in New York and northern New England over similar periods. Unadjusted Medicare mortality trends were generally similar in the states under study, and in the United States as a whole. Conclusions.-In-hospital mortality after CABG surgery has decreased in Massachusetts despite the absence of statewide outcome reporting. Direct program evaluations are needed to better characterize the efficacy of the ongoing statewide outcome studies in New York and northern New England.