AIM: To assess the utility of using external databases for quality improvement (QI) evaluations in the context of an innovative QI collaborative aimed to reduce three infections and improve patient safety across the cardiac surgery service line. METHODS: We compared changes in each outcome between 15 intervention hospitals (infection reduction protocols plus safety culture intervention) and 52 propensity score-matched hospitals (feedback only). RESULTS: Improvement trends in several outcomes among the intervention hospitals were not statistically different from those in comparison hospitals. CONCLUSION: Using external databases such as those of professional societies may permit comparative effectiveness assessment by providing concurrent comparison groups, additional outcome measures and longer follow-up. This can better inform evaluation of continuous QI in healthcare organizations.