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Comparison of sleep characteristics during the first and second period of restrictive measures due to COVID-19 pandemic in Greece.

OBJECTIVE
The first wave of coronavirus pandemic and concomitant restrictive measures affected sleep. We slept more than usual, but the quality was worse. As the pandemic continues, a second period of restrictive measures was initiated, and no data exist about their impact on sleep. The aim of this study was to compare quantity and quality of sleep between the two periods of restrictive measures, due to the Coronavirus Disease-19 (COVID-19) pandemic in Greece.


MATERIALS AND METHODS
A web-based survey using a short 13-item questionnaire was created and was distributed online. This included information about demographic and professional data, quantitative and qualitative characteristics of sleep, degree of abidance in lockdown measures, and data about COVID-19 infection or close contact with active confirmed cases.


RESULTS
A total of 1,078 questionnaires were evaluated (first period, n=963; second period, n=115). Sleep duration was shorter during the second lockdown (mean difference -0.51h; 95% confidence interval, (CI), -0.82, -0.19, p=0.002). Compared to usual habits, sleep increased in first wave (mean difference +0.37h; 95% CI, 0.26, 0.47; p<0.001) and decreased in second wave (mean difference -0.35h; 95% CI, -0.60, -0.09; p=0.009). Regarding quality of sleep, less participants reported good quality of sleep during the second wave compared to the first (p=0.006). Finally, compliance to restriction measures was lower and the prevalence of confirmed illness or close contact with COVID-19 cases among participants was higher during the second period than during the first one (p<0.001 and p=0.028, respectively).


CONCLUSIONS
Our data showed that sleep duration increased during the first lockdown and decreased in the second one, when compared to usual habits. Moreover, sleep quality progressively deteriorated, as the restrictive measures due to coronavirus pandemic continued.