The aim of this study was to determine if the lockdown measures applied due to the pandemic of Coronavirus Disease 2019 (COVID-19) affected the sleep of the general population and health professionals in six different countries (Greece, Switzerland, Austria, Germany, France, and Brazil). We used a web-based survey with a short questionnaire of 13 questions, translated into four languages (Greek, German, French, and Portuguese). The questionnaire included information about demographic and professional data, quantitative and qualitative characteristics of sleep, degree of abidance in lockdown measures, and data about illness or close contact with active confirmed cases of COVID-19. Initially, 2093 individuals participated. After exclusion of those who did not report their duration of sleep, the final sample comprised 1908 participants (Greek, n = 1271; German, n = 257, French, n = 48; Portuguese, n = 332), aged 42.6 ± 12.7 years, who were considered for further analysis. A main effect of the lockdown week on sleep duration was observed (+0.25 h; 95% confidence intervals, CI, 0.17, 0.32; p < 0.001), with the total sleep time of the lockdown week being longer than that under normal conditions. A week*occupation interaction on sleep duration was demonstrated (p < 0.001, η2 = 0.012). Sleep duration remained stable in health professionals (-0.18 h; 95% CI -0.36, 0.01; p = 0.063), whereas it increased in other occupations by 0.31 h (95% CI, 0.24, 0.39; p < 0.001). In terms of sleep quality, 15% of participants characterized their sleep as bad and 37.9% as average during the lockdown week. Almost 1 in 3 individuals (31.3%) reported worse quality of sleep during the lockdown week than under normal conditions. Sleep during the lockdown week was characterized as good by 47.1%, but only 38% of the health professionals group. In conclusion, the COVID-19 pandemic and lockdown affected sleep in different ways, depending on age, level of education, occupation, and country of residence.
Keywords: Coronavirus Disease 2019 (COVID-19); health professionals; lockdown; sleep.