Real, misreported, and backfilled adherence with paper sleep diaries

Paper-based sleep diaries play an important role in the diagnosis and treatment of insomnia disorder. Accurate self-report data help to guide therapy and track progress, both in the clinic and during research trials. Previous research with paper diaries suggests that timely adherence with self-report diaries may be an issue, which can result in biased event recall.

University students (N = 31) were asked to track their bedtime and wake time within 30 min of these events on paper-based sleep diaries. Specially designed binders covertly timestamped when participants actually wrote on their sleep diary. We assessed adherence by comparing timestamped diary usage with what participants documented in their sleep diary.

Participants self-reported they were adherent with sleep diary instructions 97.9% of the time. However, timestamped data revealed that only 37.1% of diary entries were completed within the instructed timeframe. More than half of participants backfilled diary data, and three participants (9.7%) provided data that completely did not match their actual time of completion.

When naïve to the objective tracking of their sleep diary usage, participants greatly over-reported the extent of their adherence. Non-adherence with sleep diary protocols poses a challenge for researchers utilizing this tool as a study outcome in clinical trials and for clinicians attempting to implement behavioral therapies for insomnia.