Considerations for the analysis of longitudinal electronic health records linked to claims data to study the effectiveness and safety of drugs.

Health insurance claims and electronic health records (EHR) databases have been considered the preferred data sources with which to study drug safety and effectiveness in routine care. Linking claims data to EHR allows researchers to leverage the complementary advantages of each data source to enhance study validity. We propose a framework to evaluate the need for supplementing claims data with EHR and vice versa to optimize outcome ascertainment, exposure assessment, and confounding adjustment.