Recall of medication use, self-care activities and pain intensity: a comparison of daily diaries and self-report questionnaires among low back pain patients

Aim: We aimed to compare recalled information on medication use, self-care activities and pain intensity among primary care low back pain consulters with diary records of the same events. Background: Concerns are often expressed regarding the validity of recalled information about past experience of health events such as pain or its treatment. Comparing with information collected using daily diaries is one method of validating recalled findings. Methods: Patients completed diaries recording their medication use, self-care activities and pain intensity each day for two weeks. Immediately following this period, patients completed questionnaires asking for recall of their medication use, self-care activities and least, worst, usual and current pain for the previous two weeks. The recalled information obtained from the questionnaires was compared with data from the daily diaries using intraclass correlation coefficients (ICC) and k, with one-sided 95% confidence intervals. Findings: All 29 participants returned 11 or more diaries. Validity of questionnaire-based recall for medication use and self-care activities was good, with everyone who reported use in the diaries also reporting this on the questionnaires (both k51.0). However, some specific medications (eg, diclofenac) were over-reported in the questionnaires, and some self-care activities (eg, exercises) were under-reported. Combinations of pain intensity ratings were more accurate than single ratings; the mean of the recalled least, usual and current pain intensities was closest to the diary ratings (ICC 0.94, mean difference 0.13). The generalisability of these findings to other settings, recall periods and patient groups remains to be established.