Recent Trends in Sedentary Behaviors among Chinese Children According to Demographic and Social Characteristics.

Objective This study aims to explore trends in sedentary behavior among Chinese children aged 6-17 years per demographic and social characteristics. Methods A total of 4,341 children aged 6-17 years who participated in the China Health and Nutrition Survey from 2004 to 2015 were included. Repeated measures from mixed-effects models were applied to test trends in sedentary behaviors, which were further analyzed after applying stratification according to gender, age, urbanization level, residential area, and region. Random-effects ordinal regression models were used to examine the trends at sedentary levels. Results From 2004 to 2015, sedentary time among children aged 6-17 years increased from 23.9 ± 0.6 h/week to 25.7 ± 0.6 h/week ( P < 0.001). Increases of 3.1 h/week ( P < 0.001), 2.3 h/week ( P = 0.012), and 1.3 h/week ( P = 0.042) were found among the low-, medium-, and high-urbanization groups respectively and increased by 2.0 h/week ( P < 0.001) and 1.3 h/week ( P = 0.002) among rural and urban children, respectively. The proportion of Chinese children with average daily screen time below 2 hours declined by 10.2% ( OR = 0.51, 95% CI: 0.42-0.63, P < 0.001); a decreasing trend was observed in both boys and girls. Conclusions Sedentary time among Chinese children aged 6-17 years showed an upward trend from 2004 to 2015, especially among children residing in rural areas and regions with low urbanization levels.