BACKGROUND: Accurate and efficient outcome reporting is of growing importance as governments seek to ensure they are achieving appropriate value for money. Outcome reporting is also of great value to support quality improvement and monitoring. The Cardiac Care Network of Ontario (CCN) and the Canadian Institute for Health Information (CIHI) report on outcomes of patients receiving isolated Coronary Artery Bypass Graft (CABG) surgery and Percutaneous Coronary Interventions (PCI). Different data sources and methodologies are leveraged by both organizations to calculate these outcomes. The objective of this study is to compare the methodology used and the outcomes reported from these initiatives and to identify potential reasons for any observed differences.
METHODS AND RESULTS: For this study, CCN analyzed data from October 1, 2011 to March 31, 2016 while CIHI analyzed data from April 1, 2013 to March 31, 2016. CCN’s 30-day mortality rate was calculated by linking CCN Cardiac Registry data to the CIHI Discharge Abstract Database (DAD) and the Ontario Registered Persons Database. CIHI’s 30-day in-hospital mortality rate was calculated using CIHI clinical administrative data sources including DAD and the National Ambulatory Care Reporting System (NACRS) to identify procedures and in-hospital deaths. For both reports, risk-adjustment models were created to permit statistical adjustment for patient case mix and allow comparison of outcomes between cardiac centres. Figure 1 compares the risk-adjusted 30-day mortality rates as reported by both organizations. Provincial 30-day mortality rates were relatively similar between the reports. Generally, similar trends were observed in both reports. There were however, differences observed in the rates at some hospitals between the two methodologies. These discrepancies may be explained by differences inherent in the two methodologies used: • CIHI’s methodology captured in-hospital deaths only, whereas CCN’s methodology was able to identify deaths which occur out-of-hospital; • CIHI’s risk adjustment methodology was based on a national comparison, whereas CCN’s was limited to an Ontario comparison; • CIHI used CIHI-DAD/NACRS data, whereas CCN used CCN Cardiac Registry data to identify its cohort. Validation is required to ensure that the same patients are identified across both data sources.
CONCLUSION: Overall, risk-adjusted mortality rates for PCI and CABG in Ontario are low as measured using both the CCN and CIHI methodology. While absolute results between CCN and CIHI display some differences, the trends and relative results among hospitals remain consistent. Standardized and comparable reports on procedural outcomes are an important resource to support continuous quality improvement efforts in cardiac care.
