CONCLUSIONS AND RELEVANCE: Comprehensive medication monitoring offers promise to improve adherence, the accuracy of medical records, and the safety for patients with polypharmacy.
Question What is the agreement between prescribed medications in the electronic health record and empirically measured drug concentrations for 263 frequently prescribed and coprescribed medications?
Findings In this cross-sectional study of 1346 patients in 3 different health care settings, 78% to 100% of medications were detected as prescribed in the electronic health record medication list. In addition, medications not included in electronic health record medication lists were detected and were more frequently associated with alerts for potential adverse drug reactions.
Meaning Medication lists in the electronic health record are often inaccurate; a method for comprehensive medication monitoring offers promise to improve adherence, reconcile medical records, and address safety and effectiveness concerns associated with the choice of medication for patients who are prescribed multiple medications.