Determinants of health-related quality of life in healthy children and adolescents during the COVID-19 pandemic: results from the longitudinal cohort study Ciao Corona (preprint)

Purpose: Understanding health-related quality of life (HRQOL) in children and adolescents, during a pandemic and afterwards, aids in understanding how circumstances in their lives impact their well-being. We aimed to identify determinants of HRQOL from a set of biological, psychological and social factors. Methods: Data was taken from a longitudinal sample (n = 1843) of children and adolescents enrolled in the prospective school-based cohort study Ciao Corona in Switzerland. The primary outcome was HRQOL, assessed using the KINDL total score and its subscales (each from 0, worst, to 100, best). Potential determinants, including biological (physical activity, screen time, sleep, chronic conditions, etc), psychological (sadness, anxiousness, stress) and social (nationality, parents education, etc) factors, were assessed in 2020 and 2021, and HRQOL in 2022. Determinants were identified in a data-driven manner using recursive partitioning to define homogeneous subgroups, stratified by school level. Results: Median KINDL total score in the empirically identified subgroups ranged from 68 to 83 in primary school children and from 69 to 82 in adolescents in secondary school. The psychological factors sadness, anxiousness and stress in 2021 were identified as the most important determinants of HRQOL in both primary and secondary school children. Other factors, such as physical activity, screen time, chronic conditions or nationality, were determinants only in individual subscales. Conclusion: Recent mental health, more than biological, physical or social factors, played a key role in determining HRQOL in children and adolescents during pandemic times. Public health strategies to improve mental health may therefore be effective in improving HRQOL in this age group.

Health-related quality of life and adherence to lifestyle recommendations in schoolchildren during the COVID-19 pandemic: results from the longitudinal cohort study Ciao Corona (preprint)

Objectives: Both lifestyle and health-related quality of life (HRQOL) were compromised during the COVID-19 pandemic. Our aim was to investigate changes in adherence to physical activity and screen time recommendations of children and adolescents throughout the pandemic, and their association with HRQOL over time. Methods: Longitudinal data in 1769 primary (grades 1-6) and secondary (7-9) school children ages 6-17 years was taken from the Ciao Corona study, a school-based prospective cohort study in Zurich, Switzerland, with 5 online questionnaires between June 2020 and July 2022. HRQOL was assessed using the KINDL questionnaire. Meeting physical activity and screen time recommendations was defined according to criteria of the world health organization. Results: Adherence to physical activity recommendations dropped in 2020, but had returned to approximately pre-pandemic levels by 2022. Fewer children met screen time recommendations in 2020 and 2021 than pre-pandemic. HRQOL reduced approximately 3 points between 2020 and 2022, and was on average 9.7 points higher (95% CI 3.0 - 16.3) in March 2021 in children who met both recommendations. Conclusions: Adherence to WHO guidelines on physical activity and screen time during the pandemic had a consistent association with HRQOL despite longitudinal changes in behavior.

Lifestyle behaviours of children and adolescents during the first two waves of the COVID-19 pandemic in Switzerland and their relation to well-being: a population-based study (preprint)

Background: Previous studies assessing the impact of the COVID-19 pandemic on children's and adolescent's lifestyle focused mainly on the first wave in early 2020. We aimed to describe changes in adherence to recommendations for physical activity (PA), screen time (ST), and sleep duration over the first two waves of the pandemic (March-May 2020 and October 2020-January 2021) in Switzerland, and to assess the associations of these lifestyle behaviours with life satisfaction and overall health, as indicators of well-being. Methods: We included 3168 participants aged 5 to 18 years from four Swiss cantons. Participants or their parents completed repeated questionnaires and reported on their (child's) PA, ST, sleep, life satisfaction, and overall health. We analysed lifestyle behaviours in terms of adherence to international recommendations. We used linear and logistic regression models to assess the associations of number of recommendations met and adherence patterns with well-being indicators. Findings: Compared to the pre-pandemic period, the percentage of participants meeting the recommendations for PA and ST decreased strikingly during March-May 2020, while there was a slight increase in those meeting recommendations for sleep. During October 2020-January 2021, the percentage of compliant children for PA and ST increased but remained lower than before the pandemic. Participants meeting all three recommendations were more likely to report excellent health (OR: 1.87 [1.15-3.08]) and a higher life satisfaction score ({beta}: 0.59 [0.30-0.88]) than participants not meeting any recommendation. Adherence to recommendations for PA and sleep, PA and ST, and sleep and ST was similarly associated with both well-being indicators. Interpretation: We show a substantial impact of the COVID-19 pandemic on children's and adolescents' lifestyle behaviours with a partial recovery over time, and an association between lifestyle and well-being. Public health policies to promote children's and adolescents' well-being should target PA, ST, and sleep simultaneously. Funding: Corona Immunitas.