Both sleep diaries and actigraphy have been recommended to assess sleep in research and clinical settings. Investigators have traditionally used sleep diaries that were completed daily by participants and collected weekly but have recently begun using sleep diaries that are both completed and collected daily. No research had previously assessed the agreement between daily-collected sleep diaries and actigraph data over one week. Undergraduate students were randomly assigned to use daily- or weekly-collected sleep diaries. Sleep parameters obtained from these measures were compared to each other via concordance with concurrent actigraph data. It was hypothesized that daily-collected sleep diaries would have greater concordance with actigraphy than weekly-collected sleep diaries. Results indicated that daily-collected sleep diaries provided more reliable data than weekly-collected sleep diaries, but the differences were not statistically significant. Additional aims examined self-reported sleep diary adherence, the participation day number, and day of the week. There were trends for the Daily group to have better adherence. Overall concordance did not change based on the day number or day of the week. Both sleep diaries yield comparable sleep parameter data, suggesting that clinicians and researchers can use either method to estimate sleep parameters.

Self-report retrospective estimates of sleep behaviors are not as accurate as prospective estimates from sleep diaries, but are more practical for epidemiological studies. Therefore, it is important to evaluate the validity of retrospective measures and improve upon them. The current study compared sleep diaries to two self-report retrospective measures of sleep, the commonly used Pittsburgh Sleep Quality Index (PSQI) and a newly developed sleep questionnaire (SQ), which assessed weekday and weekend sleep separately. It was hypothesized that the new measure would be more accurate than the PSQI because it accounts for variability in sleep throughout the week. The relative accuracy of the PSQI and SQ in obtaining estimates of total sleep time (TST), sleep efficiency (SE), and sleep onset latency (SOL) was examined by comparing their mean differences from, and correlations with, estimates obtained by the sleep diaries. Correlations of the PSQI and SQ with the sleep diaries were moderate, with the SQ having significantly stronger correlations on the parameters of TST, SE, and sleep quality ratings. The SQ also had significantly smaller mean differences from sleep diaries on SOL and SE. The overall pattern of results indicated that the SQ performs better than the PSQI when compared to sleep diaries.