Comparison of 7-day and repeated 24-h recall of type 2 diabetes

Patient reporting of type 2 diabetes symptoms in a questionnaire with a 7-day recall period was expected to be different from symptom reports using a 7-day diary with repeated 24-h recall based on cognitive theory of memory processes and prior literature. This study compared these two types of recall in patients diagnosed with type 2 diabetes (T2D). One hundred and forty adults with T2D completed a daily diary for 7 days containing 9 T2D-related symptom and impact items. On day 7, patients completed the same items with a 7-day recall period. We examined the concordance of 7-day recall with summary descriptors of the daily reports and compared the scores and the discriminant ability of 7-day recall and mean of daily reports. Seven-day recall was most concordant with the mean of daily reports. The average difference in scores was small (range 0.22-0.77 on 11-point scale) and less than 0.5 standard deviations. For some items, the difference was positively associated with the variation in daily reports. The discriminant ability was comparable. In this study population, a questionnaire with 7-day recall provided information consistent with a daily diary measure of the average week-long experience of T2D symptoms and impacts.