Impact of interview mode on accuracy of child and parent report of adherence with asthma-controller medication

OBJECTIVES. Parents and children often overreport adherence to treatment regimens, which in turn complicates interpretation and application of clinical trial findings. The objective of this investigation was to test the effect of reporting mode on accuracy of inhaled corticosteroid-adherence reporting in children with asthma and their parents under conditions similar to those of an asthma clinical trial. PATIENTS AND METHODS. Participants included 104 children who were being treated with an inhaled corticosteroid delivered by a metered-dose inhaler for asthma diagnosed by their health care provider. Each parent and child dyad was randomly assigned to 1 of 3 self-report adherence-assessment modes: (1) audio computer-assisted self-interviewing; (2) face-to-face interview with study staff; or (3) self-administered paper-and-pencil questionnaire. At the 4 monthly visits, the parent and child were interviewed separately and asked questions about adherence on the previous day and in the past week. Electronic devices were attached to the each participant's metered-dose inhaler to provide an objective record of actual daily medication activations. RESULTS. Both children and parents greatly overreported their inhaled corticosteroid adherence when queried about either time frame (1 day or 1 week) in any of the 3 interview modes. One of 3 responses reported full adherence when no medication had been taken. Inconsistent with the study hypothesis, discrepancy between self-report and objectively measured adherence was greatest in the computer-interview condition. In the optimal circumstance where children were interviewed by study staff about their adherence within the previous 24 hours, reported adherence was within the ±25% accuracy range for only half of the participants. Larger discrepancy scores were observed for both parents and children when reporting by computer or questionnaire. CONCLUSIONS. Under the best of conditions in this study, accuracy of self-report was insufficient to provide a stand-alone measure of adherence. Verification of treatment adherence by objective measures remains necessary.