Seasonal variations in sleep duration and sleep complaints : A Swedish cohort study in middle-aged and older individuals
Subjective sleep reports are widely used research tools in epidemiology. Whether sleep reports can differ between seasons is less clear. Using multivariable binary or multinomial logistic regression analyses, in the present Swedish cross-sectional two-centre cohort study (N = 19,254; mean age 61 years), we found that participants surveyed during the summer (June–August) were more likely to report