Agreement between patients' self-report and physicians' prescriptions on nonsteroidal anti-inflammatory drugs and other drugs used in musculoskeletal disorders: the international Pharmacoepidemiologic General Research eXtension database.

PURPOSE: The use of prescription records for the assessment of exposure to nonsteroidal anti-inflammatory drugs (NSAIDs) does not capture over-the-counter drug use. This study compared patients' self-reported use to physician's prescriptions for NSAIDs and other drugs used to treat musculoskeletal disorders (MSDs). METHODS: The international Pharmacoepidemiologic General Research eXtension database includes a network of general practitioners recruiting patients without reference to diagnoses or prescriptions. Data on all drug use across France within the 2 years preceding the date of inclusion (index date) were obtained from both patients' self-reports (PSRs) and physicians' prescription reports (PPRs). Patients' reports were obtained using a structured telephone interview combined with an interview guide containing a list of drugs commonly used. Comparisons were made on exposure to four categories of MSD drugs and three time windows up to 24 months before the index date. RESULTS: Agreement between physician and patient reports was assessed on 4152 patient-physician pairs. Bias- and prevalence-adjusted kappa values showed fair agreement for nonaspirin NSAIDs, moderate to fair for nonnarcotic analgesics, high for osteoarthritis and moderate to substantial for muscle relaxants. Over-the-counter drug use was associated with greater disagreement (OR = 2.21, 95%CI = 1.05-1.38). Age was not associated with disagreement. CONCLUSION: Differences between PSR and PPR in estimating the prevalence of MSD drug use varied by the type of drug and the elapsed time from the index date. The patient-assisted interview method used in this study showed better agreement with PPR compared with standard interviews, especially for long time windows and patients older than 65 years. Copyright © 2012 John Wiley & Sons, Ltd.