Comparison of Linked <scp>EHR</scp> ‐Pharmacy Data and Administrative Claims Data: Medication Fills During Pregnancy

Many studies of medication safety during pregnancy rely on health insurance claims data. These data may not have important details about patient health. EHRs provide more complete clinical information, and they have been linked with pharmacy data to add prescription fill records. We assessed how well medication fill records agreed between linked EHR-pharmacy data and claims data for 27 commonly used medications in pregnancy. Using data from a Minnesota healthcare system, we analyzed records from 12 440 pregnancies occurring from 2017 to 2021 with health insurance benefits, prenatal care, and postnatal care. We compared the frequency of medication fills in each data source and assessed agreement using statistical methods. The datasets usually agreed on whether a patient filled a particular medication during pregnancy. However, linked EHR-pharmacy data identified slightly more individuals with medication fills during pregnancy than claims data. This suggests that linked EHR-pharmacy data may be useful for perinatal medication safety research.