This study relies on the fact that mortality rates for CABG surgery have been calculated in a standard way in a 2008 report by the US Agency for Healthcare Research and Quality (AHRQ) for a number of jurisdictions in the United States and most recently in Canada by the Fraser Institute. [...] The technical features of the calculations, along with the limitations and accuracy of the data acquired from CIHI, are presented in the Fraser Institute publication noted above. [...] Validation of the Fraser Institute’s findings for Ontario A key difference between the Fraser Institute study and the other studies surveyed above is the fact that the Fraser Institute study uses the standard AHRQ definition of CABG. [...] The reasons for the differences in the ordering of the London Health Sciences Centre and the University of Ottawa Heart Institute are unclear, but they may be caused by differences in risk adjustment models or differences in CABG performance in general when compared to ICABG, as noted above. [...] The broad concurrence of the extant literature and the Fraser Institute’s Hospital Report Card using the AHRQ standard CABG classification gives evidence that the various comparisons of hospital performance are an accu- rate representation of hospital performance with respect to CABG in Ontario, and a reasonable guide to differences in salient performance characteristics in the jurisdictions exami