Agreement and validity of electronic health record prescribing data relative to pharmacy claims data: A validation study from a US electronic health record database

Background Granular clinical and laboratory data available in electronic health record (EHR) databases provide researchers the opportunity to conduct investigations that would not be possible in insurance claims databases; however, for pharmacoepidemiology studies, accurate classification of medication exposure is critical. Objective The aim of this study was to evaluate the validity of classifying medication exposure using EHR prescribing (EHR‐Rx) data. Methods We conducted a retrospective cohort study among patients with linked claims and EHR data in OptumLabs™ Data Warehouse. The agreement between EHR‐Rx data and pharmacy claims (PC‐Rx) data (for 40 medications) was determined using the positive predictive value (PPV) and medication possession ratio (MPR)—calculated in 1‐ and 12‐month medication exposure periods (MEPs). Secondary analyses were restricted to incident vs prevalent EHR‐Rxs, age ≥65 vs