“…12 Studies in various countries have explored potential correlates of sleep duration among children, [13][14][15][16][17][18] adolescents [18][19][20][21] and adults. [22][23][24][25][26] For example, sociodemographic factors, such as ethnicity, parental education and household income, [17][18][19] as well as lifestyle factors, especially screen time (e.g., television, computer), [15][16][17]20,21 have been identified as important correlates of sleep duration among children and adolescents. In adults, additional sociodemographic correlates, including employment and marital status, as well as various factors related to lifestyle (e.g., physical activity, smoking) and physical and mental health (e.g., self-rated general health, depression, chronic conditions) were found to affect sleep duration.…”