Determinants of health-related quality of life in healthy children and adolescents during the COVID-19 pandemic: Results from a prospective longitudinal cohort study

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 broad range of biological, psychological, and social factors in a large longitudinal population-based sample. 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, 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. 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 health 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. What is Known: • Assessing health-related quality of life (HRQOL) in children and adolescents aids in understanding how life circumstances impact their well-being. • HRQOL is a complex construct, involving biological, psychological, and social factors. Factors driving HRQOL in children and adolescents are not often studied in longitudinal population-based samples. What is New: • Mental health (stress, anxiousness, sadness) played a key role in determining HRQOL during the coronavirus pandemic, more than biological or social factors. • Public health strategies to improve mental health may be effective in improving HRQOL in children. Supplementary Information The online version contains supplementary material available at 10.1007/s00431-024-05459-w.


Study characteristics
Ciao Corona was part of the Corona Immunitas research network, a program of 40 studies in Switzerland examinings seroprevalence of SARS-CoV-2 as well as related outcomes.Many questions included in the Ciao Corona surveys were the same as or very similar to those used in the other Corona Immunitas studies.The study design has been described previously [1,2].
Upon initial enrollment for serological testing, online baseline questionnaires were distributed to parents of the participating children by email to assess demographic characteristics, children's symptoms, possible SARS-CoV-2 infections and lifestyle behaviors.Parents were asked to fill the questionnaires together with their child.
Subsequently, parents and children were invited to complete further online follow-up questionnaires at the following timepoints: For each question, it is noted whether questions were included on "baseline" or "follow-up" form.If questions were introduced in later questionnaires, the specific timepoints are noted.The questions listed here are a subset of a much longer set of questions.Questions have been translated from German.

Class year
What grade is the child in school?Age-/sex-specific body mass index was compute from subjects' age, sex, height and weight according to [3].Subjects were considered overweight if the body mass index was 1 or more standard deviations above the mean norm value.

Chronic health conditions
Has a physician or medical specialist ever diagnosed your child with any of the following?

Lifestyle
The wording of the following lifestyle questions was based on that found in previous studies of lifestyle in children and adolescents [4], and has been described previous for this study [5,6].For sleep and screen time, we calculated a weighted average as follows: [(weekday*5) + (weekend day*2)]/7.The values were when used to determine adherence to international recommendations: ≥ 1 hr/day of physical activity, ≤ 2 hr/day of screen time [7], and agespecific sleep duration (10-13 hr/night for 5 years; 9-11 hr/night for 6-13 years; 8-10 hr/night for 14-16 years) [8].

Physical activity
How

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Sex of your child [baseline]• Possible responses: female, male, other/diverse Child's height How tall is your son / daughter currently?[baseline, follow-up September 2021, December 2021, June 2022] Child's weight How much does your son / daughter weigh currently?[baseline, follow-up September 2021, December 2021, June 2022] many hours of sports or other physical activities per day (that caused sweating or increased breathing) did your child do on a typical weekday BEFORE the Corona epidemic (before March 16, 2020) (including school sports)?[baseline June/July 2020] How many hours per day did your child spend using electronic devices (e.g.cell phone, Playstation, Xbox, Nintendo, computer, TV) during the Corona epidemic (period March 16, 2020 to May 11, 2020)?School lessons and schoolwork outside of school are not included.[baseline June/July 2020] Sleep Before the Corona epidemic (before March 16, 2020), how many hours per day did your child sleep on a typical weekday?[baseline June/July 2020] How many hours per day did your child sleep on a typical weekday during the Corona epidemic (March 16, 2020 to May 11, 2020)?[baseline June/July 2020] symptoms, fatigue, stuffy/runny nose, chest tightness, chest pain, cough, muscle pain, joint pain or swelling, headache, change sense of taste, changed sense of smell, difficulty concentrating, difficulty sleeping, increased need for sleep, weight loss, diarrhea, stomach pain, constipation, skin rash, palpitations, other [with comment field] Since the last survey, has your son/daughter had any symptoms/complaints that lasted at least 4 weeks (1 month)?If NO, please select "No symptoms".If YES, select the appropriate symptom(s).[follow-up June 2022] • possible responses [multiple possible]: no symptoms, fatigue, stuffy/runny nose, chest tightness, chest pain, cough, wheezing, sore throat, muscle pain, joint pain or swelling, headache, dizziness, change sense of taste, changed sense of smell, difficulty concentrating, What is the nationality of the father (the life partner of the mother)?[baseline] • Possible responses (multiple answers possible): Switzerland, Germany, Austria, France, Italy, Spain, Portugal, Great Britain, USA, Turkey, Serbia, Montenegro, Kosovo, Croatia, other [with comment field] What is the mother's (father's partner)'s highest level of education?• Possible responses: No diploma, compulsory education, completed apprenticeship, college preparatory high school, vocational/technical university, university, don't know, other [with comment field] (Note: comments were also used to categorize all subjects who checked "other" into the above categories. many hours of sports or other physical activities per day (that caused sweating or increased breathing) did your child do on a typical weekend day BEFORE the Corona epidemic (before March 16, 2020) (including school sports)?[baselineJune/July 2020] How many hours of sports or other physical activities per day (that caused sweating or increased breathing) did your child do DURING the Corona epidemic (March 16 to May 11, 2020) (including school sports)?[baselineJune/July 2020] How many hours of sports or other physical activity per day (that caused sweating or increased breathing) does your son/daughter CURRENTLY do on a typical weekday (Monday to Friday)?Please include school sports.[baselineNovember/December 2021, June 2022, follow-up] How many hours of sports or other physical activity per day (that caused sweating or increased breathing) does your son/daughter CURRENTLY do on a typical weekend day (Saturday, Sunday)?[baseline November/December 2021, June 2022, follow-up] Screen time How many hours per day did your child spend using electronic devices (e.g.cell phone, Playstation, Xbox, Nintendo, computer, TV) before the Corona epidemic (before March 16, 2020)?School lessons and schoolwork outside of school are not included.[baselineJune/July 2020] How many hours per day does your son/daughter CURRENTLY spend using electronic devices (e.g.cell phone, computer) for school on a typical weekend day (Saturday and Sunday)?[baseline November/December 2021, June 2022, follow-up September 2021, December 2021, June 2022] • Possible responses: daily, several times a week, about once a week, about once a month, rarely or never I felt anxious, worried [baseline June/July 2020, November/December 2012, June 2022, follow-up] • Possible responses: daily, several times a week, about once a week, about once a month, rarely or never How would you rate the stress in your child's life right now? [baseline November/December 2021, June 2022, follow-up] • Possible responses: 1 (no stress), 2, 3, 4, 5, 6 (extreme stress)5 Symptoms compatible with post-Covid-19 condition Has your child had any symptoms/complaints since fall break that have lasted at least 4 weeks?If NO, please select "No symptoms".If «YES», select the corresponding symptom(s).[follow-up March 2021] • possible responses [multiple possible]: no ) What is the father's (mother's partner)'s highest level of education?• Possible responses: No diploma, compulsory education, completed apprenticeship, college preparatory high school, vocational/technical university, university, don't know, other