The construction of the Split Sleep Questionnaire on sleep habits during the COVID-19 pandemic in the general population

Aim To construct a single-format questionnaire on sleep habits and mood before and during the COVID-19 pan-demic in the general population. Methods We constructed the Split Sleep Questionnaire (SSQ) after a literature search of sleep, mood, and lifestyle questionnaires, and after a group of sleep medicine experts proposed and assessed questionnaire items as relevant/irrelevant. The study was performed during 2021 in 326 respondents distributed equally in all age categories. Respondents filled out the SSQ, the Pittsburgh Sleep Quality Index (PSQI), and State Trait Anxiety Inventory (STAI), and kept a seven-day sleep diary. Results Cronbach alpha for Sleep Habits section was 0.819, and 0.89 for Mood section. Test-retest reliability ranged from 0.45 (P = 0.036) for work-free day bedtime during the pandemic to 0.779 (P < 0.001) for sleep latency before the pandemic. Workday and work-free day bedtime during the COVID-19 pandemic assessed with SSQ were comparable to the sleep diary assessment (P = 0.632 and P = 0.203, respectively), as was the workday waketime (P = 0.139). Work-free day waketime was significantly later than assessed in sleep diary (8:19 +/- 1:52 vs 7:45 +/- 1:20; P < 0.001). No difference in sleep latency was found between the SSQ and PSQI (P = 0.066). ConclusionThe SSQ provides a valid, reliable, and efficient screening tool for the assessment of sleep habits and associated factors in the general population during the COVID-19 pandemic.