Health-related quality of life and adherence to physical activity and screen time recommendations in schoolchildren: longitudinal cohort Ciao Corona

Objectives We investigated changes in adherence to physical activity (PA) and screen time (ST) recommendations of children and adolescents throughout the pandemic, and their association with health-related quality of life (HRQOL). Methods 1769 primary (PS, grades 1-6) and secondary (SS, 7-9) school children from Ciao Corona, a school-based cohort study in Zurich, Switzerland, with 5 questionnaires 2020-2022. HRQOL was assessed using the KINDL questionnaire. PA (≥ 60 min/day moderate-to-vigorous PA) and ST (≤ 2 hours/day ST) recommendations followed WHO guidelines. Results Adherence to PA recommendations dropped in 2020 (83% to 59% PS, 77% to 52% SS), but returned to pre-pandemic levels by 2022 (79%, 66%). Fewer children met ST recommendations in 2020 (74% PS, 29% SS) and 2021 (82%, 37%) than pre-pandemic (95%, 68%). HRQOL decreased 3 points between 2020 and 2022, and was 9.7 points higher (95% CI 3.0-16.3) in March 2021 in children who met both versus no recommendations. Conclusions Adherence to WHO guidelines on PA and ST during the pandemic had a consistent association with HRQOL despite longitudinal changes in behavior.