Prescription data improve the medication history in primary care

Background Incomplete medication lists increase the risk of medication errors and adverse drug effects. In Denmark, dispensing data and pharmacy records are available directly online to treating physicians. We aimed (1) to describe if use of pharmacy records improved the medication history among patients consulting their general practitioner and (2) to characterise inconsistencies between the medication history reported by the patient and the general practitioner's recordings. Methods Patients attending a general practitioner clinic were interviewed about their current medication use. Subsequently, the patients were contacted by phone and asked to verify the medication list previously obtained. Half of the patients were randomly selected for further questioning guided by their dispensing data: during the telephone interview, these patients were asked to clarify whether drugs registered in their pharmacy records were still in use. Pharmacy records show all drugs acquired on prescription from any national pharmacy in the preceding 2 years. The medication list was corrected accordingly. In all patients, the medication lists obtained on the in-clinic and telephone interviews were compared to the general practitioner's registrations. Results The 150 patients included in the study had a median age of 56 years (range 18-93 years), and 90 (60%) were women. Patients reported use of 849 drugs (median 5, range 0-16) at the in-clinic interview. Another 41 drugs (median 0, range 0-4) were added during the telephone interview. In the subgroup of 75 patients interviewed guided by pharmacy records, additionally 53 drugs (10%) were added to the 474 drugs already mentioned. The 27 patients adding more drugs guided by pharmacy records were significantly older and used more drugs (both p<0.05) than the 48 patients not adding drugs. When the medication lists were compared with the general practitioner's lists, specifically use of over-the-counter products and prescription-only medications from Anatomical Therapeutic Chemical Classification System group J, A, D, N and R were not registered by the general practitioner. Discussion Dispensing data provide further improvement to a medication history based on thorough in-clinic and telephone interviews. Use of pharmacy records as a supplement when recording a medication history seems beneficial, especially among older patients treated with polypharmacy.