Reason for discontinuation of newly prescribed antihypertensive medications: methods of a pilot study using computerized patient records.

Objective-The purpose of this pilot study was to examine the feasibility of using computerized medical records retrospectively to identify patients and their physicians for subsequent survey to examine discontinuation of a newly prescribed antihypertensive medication in primary care, while maintaining patient confidentiality.Design-A case - control study utilizing UKPCD (formerly MediPlus(R)), a large automated database of computerized medical records, and direct collection of information from patients and their physicians.Setting-Eight selected general practices in the United Kingdom.Participants-Thirty-two patients, identified with a newly prescribed antihypertensive (index) medication and classified by their treatment status (discontinuer vs continuer) and five physicians were surveyed.Results-The participation rate was low among physicians (19%), likely to be due to recruitment during the holiday season, but higher among eligible patients (70%). A higher proportion of discontinuers (37%) refused or failed to respond to the invitation to participate compared with continuers (27%). For most patients, self-reported treatment status matched the UKPCD-based classification of discontinuer or continuer (kappa = 0.67); agreement of UKPCD data with physicians was moderate (kappa = 0.53). The extent and accuracy of the information collected from patients demonstrated that they were able and willing to report detailed knowledge of their medications and recent symptoms. Discontinuers, however, had difficulty recalling the discontinued medication on their own, possibly due to the amount of time elapsed between the event and the questionnaire administration.Conclusion-This pilot study demonstrates the feasibility of examining medication discontinuation in an ambulatory setting by utilizing a large automated database of computerized records to identify and recruit eligible physicians and their hypertensive patients for study, while maintaining patient and physician privacy. Modifications to the methodology to increase physician and patient participation and recall, and to decrease the time between the index event and patient query would increase its utility in larger studies. Copyright (c) 2000 John Wiley & Sons, Ltd.