Negative self-rated health, physical activity and sitting time in Brazilian adolescents: moderating effects of sociodemographic and behavioural aspects

Abstract

Insufficient physical activity and sedentary behaviour can impact perceived health levels, which are important markers for the occurrence of morbidities and early mortality. The aim was to estimate the prevalence and direct associations, as well as to consider possible moderating effects of sociodemographic and behavioural characteristics, between physical activity and sitting time with negative self-assessment of health, according to gender, in Brazilian adolescents. This cross-sectional study uses data from the 2019 National School Health Survey (PeNSE). The outcome was negative self-assessment of health. The independent variables were physical activity and sitting time. The association measure employed was Prevalence Ratios (PR), supplemented by 95% confidence intervals (95%CI). The prevalences of negative self-assessment of health were 2.8 (95%CI 2.4–3.3) and 5.8% (95%CI 5.1–6.5) among boys and girls, respectively. The prevalence of negative self-assessment of health in Brazilian adolescent girls was 1.5 times higher for those with high sitting time. Younger male adolescents with sitting time ≥ 3 hours/day had 2.64 (95%CI 1.38–5.05) times higher prevalence of negative self-assessment of health. It is concluded that girls were more prone to negative self-assessment of health. Age influenced the association between sedentary behaviour and perceived health level in boys.