Assessing the accuracy of computerized medication histories.

OBJECTIVE: To determine the accuracy of computerized medication histories. STUDY DESIGN: Cross-sectional observational study. PATIENTS AND METHODS: The study sample included 493 Department of Veterans Affairs primary care patients aged 65 years or older who were receiving at least 5 prescriptions. A semistructured interview confirmed medication, allergy, and adverse drug reaction (ADR) histories. Accuracy of the computerized medication lists was assessed, including omissions (medications not on the computer record) and commissions (medications on the computer record that were no longer being taken). Allergy and ADR records also were assessed. RESULTS: Patients were taking a mean of 12.4 medications: 65% prescription, 23% over-the-counter products, and 12% vitamins/herbals. There was complete agreement between the computer medication list and what the patient was taking for only 5.3% of patients. There were 3.1 drug omissions per patient, and 25% of the total number of medications taken by patients were omitted from the electronic medical record. There were 1.3 commissions per patient, and the patients were not taking 12.6% of all active medications on the computer profile. In addition, 23.2% of allergies and 63.9% of ADRs were not in the computerized record. CONCLUSIONS: Very few computerized medication histories were accurate. Inaccurate medication information may compromise patient care and limit the utility of medication databases for research and for assessment of the quality of prescribing and disease management.