Association of health predictors with quality of life in children and adolescents.

Objectives: To evaluate the association of health-related quality of life (HRQOL) with physical activity, food consumption, sleep duration and screen time in children and adolescents.

Methods: Cross-sectional study with 268 students aged 10-17 years from a public school in Brazil. The outcome variable was HRQOL score, evaluated by the Pediatric Quality of Life Inventory™ (PedsQL™). Exposure variables were habitual physical activity, food consumption, sleep duration, and screen time. A general linear model was used to estimate age-adjusted means and 95 % confidence interval (95 % CI) of HRQOL scores, and a multivariable analysis of variance to identify factors associated with lower/higher HRQOL scores. The study was approved by the Human Research Ethics Committee of the Pontifical Catholic University of Campinas.

Results: Overall HRQOL score was 70.3 (95 % CI: 68.0-72.6). Multivariable analyses showed lower HRQOL scores for those adolescents who: 1-were physically inactive (67.3; p=0.014); 2-sleep less than 6 h per night (66.8; p=0.003); 3-eat fruits and vegetables less than five days/week (68.9; p=0.027); and 4-eat fast food twice/week or more (68.6; p=0.036) when compared to their opposite groups. Screen time was not statistically significantly associated with total HRQOL.

Conclusions: The joint association found in our study suggests that at least three habits must change to improve the HRQOL of children and adolescents (physical activity, food consumption, and sleep duration). Therefore, interventions in schools to promote a healthy lifestyle to achieve a better HRQOL should include a multidisciplinary team to properly guide children and adolescents about these habits simultaneously.