Factors associated with adolescents' physical inactivity in Xi'an City, China.

PURPOSE: To explore the sociodemographic and environmental factors at community, school, and household levels associated with physical inactivity.

METHODS: In a cross-sectional study in 2004, physical activity level was assessed using a validated questionnaire in 1787 students. Physical inactivity was defined as less than 150 min.wk of moderate activity (4-6 METs) or less than 60 min.wk of vigorous activity (> 6 METs). Sociodemographic and environmental information was recorded on self-administered questionnaires. Hierarchical multiple logistic models were developed based on a conceptual framework of factors related to physical activity.

RESULTS: Overall, girls were twice as likely to be inactive. Adolescents aged 14 yr were 30% less likely to be inactive compared with those younger than 13 yr (95% CI: 0.5-0.9). Paternal education was inversely associated with inactivity (OR: 0.6, 95% CI: 0.4-0.9). Adolescents living in neighborhoods without sidewalks were 1.3 times more likely to be inactive (95% CI: 1.0-1.6). At the school level, lack of extracurricular exercise (OR: 1.3, 95% CI: 1.1-1.6) and fewer sports meetings (OR: 2.0, 95% CI: 1.4-2.9) were associated with physical inactivity. Difficult access to community recreational facilities (moderate OR: 1.4, 95% CI: 1.0-1.9; difficult OR: 1.7, 95% CI: 1.2-2.4) and concerns about safety in the neighborhood (OR: 2.1, 95% CI: 1.1-4.1) were associated with inactivity. There were some differences associated with physical inactivity between boys and girls.

CONCLUSION: Strategies to promote physical activity in Chinese adolescents should integrate associated factors at household, school, and community levels and address the important gender differences in factors associated with physical inactivity in youth.