Associations between in-school-hours physical activity and child health-related quality of life: A cross-sectional study in a sample of Australian primary school children.

The aim of the current study was to examine the association between Australian primary school children's objectively measured in-school-hours weekly physical activity (PA) and their health-related quality of life (HRQoL). A cross-sectional study of 1128 Grade 2 and 3 children, aged 7-9 years, from 62 primary schools was conducted in New South Wales, Australia between October 2017 and April 2018. Children's PA was assessed via an accelerometer worn for five days during school hours. Their parents completed a telephone interview, answering demographic, child HRQoL and out-of-school-hours PA questions. Children's in-school-hours PA was classified as total PA and moderate-to-vigorous PA (MVPA). HRQoL scores were aggregated and reported at the high construct level domains (Total Quality of Life (Total HRQoL), Physical and Psychosocial Health Summary Scores). Multiple linear mixed regression analyses accounting for clustering were conducted to evaluate the association between children's in-school-hours weekly PA and their HRQoL. After adjusting for potential confounders, significant positive associations were found between children's in-school-hours weekly total PA and Total HRQoL (0.62 units, 95% CI: 0.29; 0.94, p < 0.001), Physical (0.71 units, 95% CI: 0.38; 1.04, p ≤ 0.001) and Psychosocial (0.58 units, 95% CI: 0.19; 0.97, p = 0.004) scores, with a stronger association observed between average weekly MVPA than average weekly total PA. There were also positive associations between PA and HRQoL for each sex when analysed separately. Our findings demonstrate a positive association between children's objectively-measured in-school-hours PA and parent-reported child HRQoL, strengthening evidence supporting the continued implementation of school-based PA programs for broader health outcomes.