Association Between Outdoor Activity and Insufficient Sleep in Chinese School-Aged Children.

BACKGROUND The aim of this study was to explore the relationship between outdoor activity (OA) and insufficient sleep duration (ISD) among Chinese children and to assess the potential age- and gender-specific effects. MATERIAL AND METHODS A national sample of 62 517 children aged 6-17 years were recruited from 7 provinces of China in the autumn of 2013. Children and their caregivers reported daily sleep duration (<7 h, 7-9 h and ≥9 h), daily OA time (<1 h, 1-2 h, and ≥2 h), and other behavior and demographic information by standardized questionnaire. ISD was defined as <9 h/day. Logistic regression analysis was used to evaluate the relationship between ISD and OA. RESULTS In total, 46 639 children (50.9% boys) completed this survey. The prevalence of ISD was 74.9% (73.7% in boys and 76.1% in girls). Stratified by age, compared with <1 h OA, the odds ratios for ISD were 0.67 (95% confidence interval: 0.62-0.72, aged 6-13 years) and 0.69 (0.49-0.98, 14-17 years) in the ≥2 h OA group; 0.91 (0.85-0.97, 6-13 years) and 0.73 (0.54-0.97, 14-17 years) in the 1-2 h OA group. Further stratified by gender, we found similar trends for both boys and girls in each age group, although some results became non-significant. CONCLUSIONS Adequate OA time per day is associated with decreased risks for ISD among children aged 6-17 years, but age and gender can modify the association.