How anxiety and depression mediate the link between sleep quality and health perception during crisis periods

Background and objectives: During crisis periods, understanding the impact of sleep quality on self-rated health becomes crucial. However, the role of anxiety and depression as potential mediators in this relationship remains insufficiently explored. Therefore, this study aimed to assess the association of sleep quality with self-rated health, and mediation by anxiety and depression. Methods: This cross-sectional, population-based study was conducted with 1,762 adults from October to December 2020 in the Iron Quadrilateral region of Brazil. The exposure variable was poor sleep quality, as measured by the PSQI. The outcome was self-rated health. The mediators tested were anxiety and depression, which were evaluated using symptoms, medical diagnoses, and the use of drugs. To test the mediators' factors, the Karlson-Holm-Breen method was used. The direct acyclic graph was used to select a minimal set of adjustments in multivariate analysis. Results: There were 22.6% of people with poor health ratings, 52.5% with bad sleep, 35.1% with worry, and 24.7% with depression. According to the multivariate analysis, individuals with poor sleep quality were 2.82 times more likely to self-assess their health as poor. The presence of anxiety and depression explained 16.57% and 5.99% of the association between poor sleep quality and poor self-rated health, respectively, in the mediation analysis. Conclusion: During the COVID-19 pandemic, individuals who had poor sleep quality had lower self-rated health. Furthermore, symptoms of anxiety and depression explained a portion of the association. Our study emphasizes the importance of evaluating individuals' sleep quality and mental health during a crisis.