Background: Previous studies suggest that nonelective coronary artery bypass graft surgery (CABG) is more costly than elective CABG. The goal of this study was to examine why cost differences exist between patients undergoing nonelective and elective CABG.
Methods: We compared the outcomes and costs of treating 1613 consecutive patients undergoing nonelective (N = 1071) and elective (N = 542) CABG at three U.S. hospitals. Participating centers each used the same cost accounting system to provide patient-level clinical and cost data. Total, direct, and overhead costs were examined as were department-level costs.
Results: Compared to elective patients, nonelective patients were of similar age (66.4 years vs 67.0 years, respectively, p = NS), but were more likely to be female (32.7% vs 24.0%, p = 0.0003). Nonelective patients had longer lengths of stay (LOS) than elective patients (9.7 +/- 0.2 days vs 6.6 +/- 0.3 days, p < 0.0001). The longer LOS among nonelective patients was primarily due to a longer preoperative LOS (2.6 +/- 0.08 days vs 0.4 +/- 0.05 days). Unadjusted in-hospital costs of treatment were 38% higher among nonelective patients ($25,111 +/-$550 vs $18,445 +/-$752, p < 0.0001). After controlling for baseline demographic and clinical differences, the increase in cost among nonelective patients was reduced to 33% (cost ratio = 1.33, 95% confidence interval = 1.27 to 1.39, p < 0.0001). The difference in cost among nonelective patients was further reduced to 16% after controlling for rates of preoperative angiography and percutaneous coronary intervention (PCI), 14% after adjusting for the use of a pacemaker or a balloon pump, and 7% after adjusting for preoperative LOS.
Conclusions: Patients undergoing nonelective CABG have longer LOS and higher costs than patients undergoing elective CABG. The increased cost among nonelective patients is largely due to differences in rates of preoperative LOS, angiography, and PCI. This differential reflects increased nonsurgical costs among patients undergoing nonelective CABG rather than surgical costs.