Influence of question structure on the recall of self-reported drug use

Epidemiological studies often rely on self-reported information as a source of drug exposure. Several studies have evaluated the accuracy of self-repo rted information on drug use. The influence of question structure on the ac curacy of recall, however, has not been studied extensively in these studie s. In this study we examined the recall accuracy of questionnaire informati on on drug use in a ongoing public health survey with special attention to the influence of question structure on sensitivity of recall. A sample of 3 72 hypertensive subjects for whom questionnaire information and pharmacy re cords were available was examined. Self-reported information on drug use wa s obtained through questions about medications used for a specific conditio n and one final open-ended question. This information was compared with the pharmacy medication history. About 71% of all drugs that were currently in use according to the pharmacy records were recalled through the self-admin istered questionnaire, and 94% of all drugs mentioned in the questionnaire could be traced in the pharmacy records. Recall sensitivity was higher for questions about medications used for a specific indication (88%) than for t he open-ended question (41%). The type of drug that was used might have cau sed part of this difference in recall. We conclude that questionnaire struc ture might be of influence on the accuracy of recall of self-reported drug use, and more attention should be paid to the structure of questions on dru g use. (C) 2000 Elsevier Science Inc. All rights reserved.