Lee CS, et al. - Researchers compared the recall rate derived using two sources—the claims-based Hospital Compare (HC) dataset from the Centers for Medicare & Medicaid Services vs the National Mammography Database (NMD) from the American College of Radiology—to understand the implications in pay-for-performance and quality improvement activities. Ninety-two facilities were unambiguously matched using 2014–2015 records in both datasets during the period from October 1 to December 1, 2016. Findings revealed that two commonly used datasets for measuring screening mammography recall rate were NMD and HC. There are important differences that have implications for quality improvement and pay-for-performance although recall rates are correlated at the individual facility level.