The COVID-19 lockdown promotes changes in sleep habits in the Croatian general population

AIM: To investigate the effects of the coronavirus disease 2019 (COVID-19) lockdown on sleep habits in the Croatian general population. METHODS: In this cross-sectional study, 1173 respondents from the general population (809 women) completed a self-report online questionnaire that gathered demographic data and data on sleep habits and mood changes before and during the COVID-19 lockdown. RESULTS: During the lockdown, bedtime (from 23:11 ± 1:07 to 23:49 ± 1:32 h, P < 0.001) and waketime were delayed (from 6:51 ± 1:09 to 7:49 ± 1:40 h, P < 0.001). Sleep latency increased from 10 (5-20) to 15 (10-30) minutes (P < 0.001). Bedtime and waketime delays were more pronounced in women and respondents younger than 30. Compared with other age groups, respondents younger than 30 more frequently reported insomnia for the first time during the lockdown and had less frequent night-time awakenings (P < 0.001), less common problems falling asleep (P < 0.001), less frequently felt calm (P < 0.001) and rested (P < 0.001), but more frequently felt sadness (P < 0.001) and fear (P = 0.028). CONCLUSION: The effect of the lockdown on sleep needs to be better understood. Sleep hygiene education could serve a first-line lifestyle intervention for people in lockdown experiencing sleep disruption.