PCORI Methodology Standards require assessing data source adequacy (IR-2) and using patient-reported outcomes when patients or people at risk for a condition are the best source of information for outcomes of interest (PC-3). However, in most cases, we do not know which data source is the most accurate. The type and extent of errors in data sources commonly employed in patient-centered outcomes research (PCOR) have not been rigorously characterized, and methods to do so are lacking. These knowledge gaps often prevent PCOR researchers from choosing a data source based on known quality and from reporting the adequacy of 2 common PCOR data sources: patient self-reported (SR) data and data from electronic health records (EHRs). This study directly addressed these gaps with the goal of advancing methods to measure the accuracy of these data sources before, during, and after a study.
