Assessment of Mental Health of High School Students 1 Semester After COVID-19–Associated Remote Schooling Measures Were Lifted in Austria in 2021

This survey study assesses whether the mental health of high school students improved 1 semester after COVID-19–associated remote schooling measures were lifted in Austria in 2021.


COVID-19 restrictions in Austria
From October 2020 to February 2021 high school took mainly place in remote schooling. During this time, no team or indoor sport was allowed. In November 2020 and from December 2020 until January 2021 one was allowed to leave the house only in a few exceptions, such as necessary purchases, assisting other people or activities outside, alone or with people living in the same household. Starting on February 8, 2021 the strict lockdown was lifted and high schools, retail shops, service providers, museums, parks, zoos etc.
were allowed to reopen with protective measures such as wearing FFP2 face masks. Classes were reopened in a shift system and extended protective measures such as weekly COVID-19 tests and mandatory FFP2-mask wearing. After six months of complete shutdown of gastronomy, hotels, events, etc., they reopened from May 19, 2021. The reopening was integrated with the "3G rule", referring to the need to prove that one has been vaccinated, tested or recovered from COVID-19, to visit restaurants, hotels, take part in events, etc.

Measures
To assess the impact of the COVID-19 pandemic and associated restrictions on mental health, internationally established, comparable, and validated instruments previously used in adolescents were used:

Well-being (WHO-5)
The WHO-5 1 comprises five self-rating items rating well-being on a six-point Likert scale. The total score was multiplied by four, resulting in a range from 0 (absence of well-being) to 100 (maximal well-being). The German version of the WHO-5 has been validated in adolescents, showing good psychometric properties. 2

Depressive symptoms (PHQ-9)
Depressive symptoms were assessed with the depression module of the Patient Health Questionnaire-9 (PHQ-9). 3 This questionnaire comprises nine self-rating items on a four-point scale ranging from 0 ("not at all") to 3 ("nearly every day") with a sum score from 0 to 27, with higher scores indicating more severe depressive symptoms. The German version of the PHQ-9 is validated for adolescents. 4 Clinically relevant depression was defined as cut-off score of ≥11 points, as this cut-off has been recommended for detecting major depression in adolescents. 5

Anxiety symptoms (GAD-7)
Anxiety symptoms were measured with the German version of the Generalized Anxiety Disorder-7 Screener (GAD-7). 6 The GAD-7 assesses anxiety with 7 self-rating items on a four-point scale, from 0 to 3 with a sum score from 0 to 21, with higher scores indicating higher anxiety levels. As suggested adolescents, 7 a cut-off score of ≥11 was used to define clinically relevant (moderate) anxiety.

Sleep quality (ISI)
The German version of the Insomnia Severity Index (ISI) is a validated screening instrument for measuring sleep quality and insomnia in adolescents. 8 The ISI comprises 7 self-reported items on a four-point scale ranging from 0 to 4, resulting in a sum score from 0 to 28, with higher scores indicating worse sleep quality.
The recommended cut-off score for clinically relevant insomnia (moderate severity) is ≥ 15 points. 9

Stress level (PSS-10)
Perceived stress level was measured with the Perceived Stress Scale-10 (PSS-10), a validated questionnaire comprising 10 self-rated items ranging from 0 to 4 (maximum score 40), with higher scores indicating higher stress levels. 10 The German version is validated for adolescents. A cut-off ≥ 27 points indicates high stress. 11

Migration status
Students were asked whether they or both parents were born abroad, to assess their migration status.

Statistical analyses
A matched pairs analysis according to age, sex, region, school type and migration status was computed using the MatchIt package 12 of R version 4.1.0. We assigned a propensity score to each participant representing the probability of belonging to one of the two groups, given a vector of observed covariates. 13 © 2021 Humer E et al. JAMA Network Open.
After systematic examination of multiple matching techniques, the 'optimal' method was chosen because it produced the best matching, as assessed by the percent balance improvement, jitter plots and histograms.
The matching process creates a new 'propensity score' variable which must be included as a covariate in all future analyses. 14 Therefore, after matching, the two time points were compared in the mental health outcome measures using linear models with time point and propensity score as fixed factors. For assessing the likelihood of being over the scale specific cut-offs for clinically relevant symptoms, general linear models were used with the binomial family. Data were analyzed from July 3 to July 28, 2021.

Completion rate
Following the American Association for Public Opinion Research (AAPOR) reporting guidelines for nonprobability online samples, 15 we report that 79.5% of those who clicked on the survey link completed the entire survey, resulting in a 79.5% participation rate (i.e., completion rate). 16