Teachers' preference for later school start times.

Early morning school start times conflict with biologically determined sleep phase preference and thus contribute to common sleep deficits. This conflict is most pronounced in adolescents, and numerous studies have confirmed that later school start times are beneficial for their sleep and health. However, the conflict continues to exist beyond adolescence and, accordingly, also teachers might benefit from later school start times, but this has gained little attention so far. Importantly, teachers' resistance to delay school start time is one of the key barriers for a successful implementation and, therefore, teachers' school start time preferences and influencing factors are important to consider. To this end, we conducted an online survey. Teachers (n = 694, 56.1% female) from 17 high schools in Zurich, Switzerland, participated in the study. They indicated their school start time preference. In addition, four predictor blocks were assessed: sociodemographic, school-/work-related, and sleep characteristics, as well as teachers' perception of students in the first morning lesson. Mixed models were applied to predict the preference. The majority (51%) endorsed later school start times (median preferred delay 25.2 min). School start time, sleep characteristics and perception of students in the first morning lesson were significant predictors for the preference. Thus, teachers with more misaligned sleep and higher awareness for students' issues in the early morning were more likely to report a preference. This suggests psychoeducation about sleep biology throughout life span to be an effective measure to increase teachers' support to delay school start time, especially because also they themselves are likely to benefit from later school start times.

Adolescents' preference for later school start times.

As the chronotype delays progressively throughout puberty, early morning school start times (SSTs) contradict the sleep biology of adolescents. Various studies have demonstrated beneficial effects of later SSTs on sleep and health; however, adolescents' preferences for SSTs have to date never been investigated in detail. The present online survey study aimed to fill this gap and explored influencing factors. A total of 17 high schools in the Canton of Zurich, Switzerland, circulated the survey among their students. Participants were included if they reported their sex, age, and school (n = 5,308). Students indicated whether they preferred later SSTs. Additionally, five predictor blocks were assessed: sociodemographic, school-related, sleep, leisure-time, and health-related characteristics. We applied multivariate logistic regression models with fixed and random effects to predict the preference. The mean (SD) age of the students was 16.09 (1.76) years (65.1% female). The majority (63.2%) endorsed later SSTs with a preferred delay of 55 min (interquartile range 25-75 min). In the multilevel analysis (n = 2,627), sex, mother tongue, sleep characteristics, mobile device use at bedtime, caffeine consumption, and health-related quality of life were significant predictors for the preference. Hence, the majority of adolescents preferred later SSTs, and especially those with sleep or health-related problems. These characteristics have been consistently shown to improve after delaying SSTs. Thus, also from adolescents' view, later SSTs should be considered to improve the adolescents' health.

Zurich Appearance Score for Hands: Development and Validation of an Instrument for Assessing Hand Appearance in Congenital Upper Limb Differences.

PURPOSE: The appearance of the hand is relevant to individual activity and participation. Improving appearance is often one of the essential goals of hand surgery. The aim of this study was to describe and validate an instrument for quantitatively assessing hand appearance in congenital upper limb differences (CULD). METHODS: The Zurich Appearance Score for Hands (ZASH) was developed as a summed score of 6 items: 1 for overall appearance and 5 specific items for the skin, proportions of the hand, the number of digits, the shape of fingers and the thumb, and the position of the thumb. Each item can be rated on an 11-point Likert scale. Here, 448 participants (age, 14-83 years) were asked to rate the images of 17 hands, including standardized 3-dimensional photorealistic computer graphics and photographs of children's hands with or without CULDs, some after surgical correction. The sociodemographic characteristics of the participants were measured using a short questionnaire. RESULTS: The ZASH score for all CULDs was significantly lower than the ZASH score for normal hands. Correlations for overall appearance and the ZASH score were high (r = 0.77-0.87). The internal consistency of all ZASH scores was good to excellent (Cronbach α = 0.82-0.94). The test-retest reliability in a subgroup of 54 participants was good (r = 0.53-0.79). The interrater reliability of the ZASH score was moderate (intraclass correlation = 0.47). CONCLUSIONS: The ZASH is a valid and moderately reliable instrument for assessing hand appearance in children with CULDs. CLINICAL RELEVANCE: Achieving the best possible appearance is the one of the most relevant goals of hand surgery. Assessment with validated instruments provides evidence on how to approach this goal. Further studies may clarify whether the ZASH can be recommended for all hand conditions and to what extent observers' sociocultural and professional backgrounds affect perception.

Actigraphy in sleep research with infants and young children: Current practices and future benefits of standardized reporting.

Actigraphy is a cost-efficient method to estimate sleep-wake patterns over long periods in natural settings. However, the lack of methodological standards in actigraphy research complicates the generalization of outcomes. A rapidly growing methodological diversity is visible in the field, which increasingly necessitates the detailed reporting of methodology. We address this problem and evaluate the current state of the art and recent methodological developments in actigraphy reporting with a special focus on infants and young children. Through a systematic literature search on PubMed (keywords: sleep, actigraphy, child *, preschool, children, infant), we identified 126 recent articles (published since 2012), which were classified and evaluated for reporting of actigraphy. Results show that all studies report on the number of days/nights the actigraph was worn. Reporting was good with respect to device model, placement and sleep diary, whereas reporting was worse for epoch length, algorithm, artefact identification, data loss and definition of variables. In the studies with infants only (n = 58), the majority of articles (62.1%) reported a recording of actigraphy that was continuous across 24 hr. Of these, 23 articles (63.9%) analysed the continuous 24-hr data and merely a fifth used actigraphy to quantify daytime sleep. In comparison with an evaluation in 2012, we observed small improvements in reporting of actigraphy methodology. We propose stricter adherence to standards in reporting methodology in order to streamline actigraphy research with infants and young children, to improve comparability and to facilitate big data ventures in the sleep community.

A behavioural intervention for young adults with dental caries, using acceptance and commitment therapy (ACT): treatment manual and case illustration.

BACKGROUND: There is a need for effective behavioural interventions in dentistry. This paper presents an innovative behavioural intervention for young adults with dental caries, in an interdisciplinary collaboration between dental personnel and licensed psychologist in general dental care. The intervention has been evaluated in an RCT, with positive effects on oral health behaviour. METHOD: The intervention, Acceptance and Commitment Therapy (ACT), a recent form of cognitive behaviour therapy (CBT), was adapted to young adult patients (18-25 years of age) with high dental caries activity. RESULTS: The intervention included two individual sessions, provided by a clinical psychologist at general dental clinics. The rationale for selecting ACT as the theory base is presented, together with the treatment manual and a case illustration. CONCLUSIONS: ACT may be a promising alternative for behavioural interventions in dentistry for patients with oral diseases, specifically dental caries. Interprofessional collaboration between psychologists and dental personnel opens up for new possibilities to help and treat patients with various health issues in public dental care. TRIAL REGISTRATION: TRN ISRCTN15009620 www.isrctn.com , retrospectively registered 14/03/2018.

Health-related quality of life outcomes in pediatric patients with cardiac rhythm devices: a cross-sectional study with case-control comparison.

BACKGROUND: Little is known about health-related quality of life (HRQoL) in pediatric patients with cardiac rhythm devices. This study aims to compare self- and proxy-reported HRQoL in patients with pacemaker (PM) and implantable cardioverter-defibrillator (ICD) to that in sex- and age-matched healthy controls and to examine predictors for generic and disease-specific HRQoL. METHODS: The study included 72 PM and ICD patients (39% females) and 72 sex- and age-matched healthy controls from 3 to 18 years of age. HRQoL data was obtained by the PedsQL 4.0 Generic Core Scales and Pediatric Cardiac Quality of Life Inventory. Medical data was collected retrospectively from medical records. RESULTS: Patients had significantly lower self- and proxy-reported generic overall HRQoL and lower physical health than healthy controls, and ICD patients also had lower psychosocial health. On multivariate analyses, generic overall HRQoL and physical health was significantly predicted by current cardiac medication (ß = -.39, p = .02 for overall HRQoL, respectively ß = -.44, p = .006 for physical health). Disease-specific overall HRQoL was only marginally predicted by child age, device type, and the presence of a structural congenital heart disease (p < .10). CONCLUSIONS: This study shows that PM and ICD patients have lower HRQoL than healthy controls and that patients who need cardiac medication are seen by their parents at great risk for lower generic overall HRQoL. Our study also indicates a trend towards higher risk for low disease-specific HRQoL in younger patients, ICD patients, and patients with a structural congenital heart disease. Special attention should be given to these patients as they may benefit from a timely clinical evaluation in order to provide supportive interventions.

Posttraumatic stress and health-related quality of life in parents of children with cardiac rhythm devices.

PURPOSE: Studies have shown a high prevalence of post-traumatic stress disorders (PTSD) among parents of children with life-threatening diseases. However, it is yet unknown whether parents of children with cardiac rhythm device develop posttraumatic stress symptoms or even PTSD. METHODS: This cross-sectional investigation is part of a comprehensive single-center study of long-term medical and psychosocial outcomes in pediatric patients with pacemaker (PM) and implantable cardioverter defibrillator (ICD). 69 patients (78%) were included in the study, with the participation of 69 mothers and 57 fathers. Parents completed the Posttraumatic Diagnostic Scale and Medical Outcomes Study Short Form-36 item questionnaire. Child's medical data was collected retrospectively from patients' hospital records. RESULTS: At assessment, the patients (39% females) were on average 11.2 years old. The predominant device type was PM in 56 cases (81%). The mean time since device implantation was 6.3 years (SD = 4.3). Full heart-disease related PTSD was diagnosed in one mother and no father, while partial heart-disease-related PTSD was diagnosed in 3 mothers (4%) and 2 fathers (4%). Parental HRQoL-especially regarding the mental health dimension-was affected in both parents. In both parents, total PTSD symptom severity scores were a significant predictor for mental health summary scores after controlling for child age at implantation, presence of other non-cardiac disease in the child, parental age, and presence of own chronic disease. CONCLUSIONS: Special attention should be given to parental PTSD symptoms in the clinical follow-up of PM and ICD patients as some parents might probably benefit from psychological support.

Health-Related Quality of Life and Psychological Adjustment of Children and Adolescents with Pacemakers and Implantable Cardioverter Defibrillators: A Systematic Review.

The absence of cardiac symptoms, the improved exercise tolerance and the increased life expectancy are the advantages of a successful cardiac device therapy. Nevertheless, the fact of a lifelong device dependency, the inherent possibility of device malfunction and the progression of the underlying heart disease may impact the health-related quality of life (HRQoL) and the psychological adjustment of these individuals. To date, an overview of findings on these topics is lacking. The objective of this study was to evaluate and summarize the current evidence on generic and disease-specific HRQoL and psychological adjustment in paediatric patients with a pacemaker (PM) or an implantable cardioverter defibrillator (ICD). A systematic literature search was conducted using relevant databases and predefined keywords. Study selection was conducted based on predefined inclusion criteria. Fourteen studies were selected which were of varying methodological quality. Overall, the studies indicated that PM/ICD patients themselves and their parents scored lower than healthy controls on generic HRQoL scales and reported similar disease-related HRQoL as patients with severe forms of congenital heart disease. Regarding psychological adjustment outcome, PM recipients and norms were not significantly different with respect to anxiety and depression symptoms, while ICD patients showed more signs of anxiety than depression. HRQoL and psychological health should be considered when setting therapy goals and evaluating medical treatment success. This approach allows an early intervention in patients at risk of maladaptation, which is especially important in the young patient undergoing crucial developmental stages.

Long-term health-related quality of life and psychological adjustment in children after haemolytic-uraemic syndrome.

BACKGROUND: In children after haemolytic-uraemic syndrome (HUS), little is known about long-term health-related quality of life (HRQoL) and psychological adjustment as defined by behavioural problems, depressive symptoms and post-traumatic stress symptoms. METHODS: Sixty-two paediatric patients with a history of HUS were included in this study. Medical data of the acute HUS episode were retrieved retrospectively from hospital records. Data on the clinical course at study investigation were assessed by clinical examination and laboratory evaluation. HRQoL and psychological adjustment data were measured by standardised, parent- and self-reported questionnaires. RESULTS: Haemolytic-uraemic syndrome was diagnosed at a mean of 6.5 years before the initiation of the study (standard deviation 2.9, range 0.1-15.7) years. Among the preschool children, parents reported that their child was less lively and energetic (HRQoL emotional dimension), while no increased behavioural problems were reported. In the school-age children, self- and proxy-reported HRQoL was well within or even above the norms, while increased total behavioural problems were found. The school-age children reported no increased depression scores. Also none of the children met the criteria for full or partial HUS-associated posttraumatic stress disorder. CONCLUSIONS: Healthcare providers should be particularly alert to behavioural problems in school-age children with a history of HUS and to lower HRQoL in preschool children.

Changes in health-related quality of life over a 1-year follow-up period in children with inflammatory bowel disease.

PURPOSE: Little is known about disease-specific health-related quality-of-life (HRQoL) changes over time in paediatric patients with inflammatory bowel disease (IBD), and about their associations with baseline medical characteristics. METHODS: In this study, 153 paediatric patients with IBD from the multicentre prospective Swiss IBD cohort study were included at baseline. Of these, 90 patients were analysed at a 1-year follow-up. Medical data were extracted from hospital records, while HRQoL data were measured using the standardized, self-report disease-specific IMPACT-III questionnaire. RESULTS: The IBD diagnosis of the included children was made an average of 2.0 years before their baseline assessment. Over the 1-year follow-up period, a significant increase in overall HRQoL and in the HRQoL domain 'physical functioning' was evident. On multivariate analysis, overall HRQoL changes over time were predicted by baseline HRQoL, baseline disease activity, and disease activity changes over time. HRQoL improvements were significantly associated with decreases in physician-assessed disease activity. Children reporting a low baseline HRQoL and children with inactive or mildly-active disease experienced greater improvements. CONCLUSIONS: Children with more severe baseline disease activity had the greatest risk for HRQoL deterioration over the 1-year follow-up period. However, among possible factors that might influence HRQoL changes over time, the child's medical characteristics explained only a small proportion of their variability in our sample. We, therefore, recommend that researchers and clinicians focus on factors that are not incorporated within the multidimensional HRQoL concept if they seek to gain better insights into factors that influence HRQoL changes over time in children with IBD.

Health-related quality of life and mental health in parents of children with hemolytic uremic syndrome.

BACKGROUND: Little is known about health-related quality of life (HRQoL) and mental health of parents having children with a history of hemolytic uremic syndrome (HUS). METHODS: This study included 63 mothers and 58 fathers of a cohort of 63 HUS-affected children. At assessment, the mean time since a child experienced an acute episode of HUS was 6.4 years. Parental HRQoL, mental health and posttraumatic stress disorder (PTSD) were assessed with standardized self-report questionnaires. Medical data were extracted from patients' hospital records. RESULTS: The HRQoL and mental health of both the mothers and fathers were not impaired compared to normative data. However, a shorter time since a child's acute HUS episode was a significant predictor of lower HRQoL among the mothers, while no such effect was found among the fathers. Two fathers (3%), but no mothers, met the criteria for a diagnosis of HUS-related full PTSD; one father (2%) and four mothers (6%) met the criteria for a diagnosis of HUS-related partial PTSD. CONCLUSIONS: Our study shows that most parents of our study sample were doing well in terms of HRQoL and mental health, although a small number met the criteria for full or partial PTSD diagnosis due to their child's HUS. We therefore recommend that healthcare providers pay special attention to parents regarding PTSD symptoms during the clinical follow-up of a HUS-affected child since some parents may benefit from psychological support.

Health-related quality of life after open-heart surgery.

OBJECTIVES: To determine health-related quality of life (HRQoL) in 1-year-old infants with congenital heart disease (CHD), to follow-up with these children at age 4 years, and to examine predictors of HRQoL. STUDY DESIGN: Parents of 144 infants who had undergone cardiopulmonary bypass surgery for CHD before age 6 months were prospectively included in this cohort study. Parents completed a standardized questionnaire on child HRQoL at 1 year and 4 years of age; medical data were extracted from the patients' hospital records. RESULTS: Parents reported a significant reduction of the children's physical functioning compared with healthy controls at age 1 year. At age 4 years, children with CHD had poorer cognitive functioning but better social functioning compared with healthy controls. Lower HRQoL at age 4 years was not significantly predicted by univentricular or biventricular CHD but was predicted by the presence of an underlying genetic defect, tube feeding at 1 year, and lower HRQoL at 1 year. CONCLUSION: This study shows that HRQoL of infants and preschool-age children with CHD is impaired in physical and cognitive dimensions. Children with lower overall HRQoL at age 1 year, an underlying genetic defect, and tube feeding need to be monitored carefully to provide appropriate and timely interventions.

[Sleep physiology and its relevance for the management of behavioral sleep disorders in children]. / Schlafphysiologie bei Kindern und deren Bedeutung für die Behandlung von nicht-organischen Schlafstörungen.

Sleep problems are among the most frequent behavioural issues during childhood. This article highlights some of the most important aspects of children's sleep physiology and presents a clinical approach for the management of behavioural sleep disorders in children. Our concept is based on developmental aspects of sleep physiology and also uses behavioural strategies for the parents and their child to handle maladaptive sleep behaviour.

Long-term neurodevelopmental outcome with hypoxic-ischemic encephalopathy.

OBJECTIVES: To determine the long-term neurodevelopmental outcome for children after hypoxic-ischemic encephalopathy (HIE) without major disability, and to examine neonatal injury patterns detected on cerebral magnetic resonance imaging (MRI) in relation to later deficits. STUDY DESIGN: Prospectively enrolled children with HIE and neonatal cerebral MRI data (n = 68) were examined at a mean age of 11.2 years (range, 8.2-15.7 years). Eleven children had a major disability (ie, cerebral palsy or mental retardation). Brain injury was scored according to the region and extent of injury. RESULTS: Children without major disability (n = 57) had lower full-scale and performance IQ scores compared with norms (P = .02 and .01, respectively), and the proportion of children with an IQ <85 was higher than expected (P = .04). Motor performance on the Zurich Neuromotor Assessment was affected in the pure motor, adaptive fine motor, and gross motor domains, as well as in the movement quality domain (all P < .001). Watershed injury pattern on neonatal MRI correlated with full-scale and verbal IQ scores (P = .006 and <.001, respectively), but neonatal MRI pattern did not correlate with motor performance in children without major disability. CONCLUSION: Children who sustained neonatal HIE without major disability are at increased risk for long-term intellectual, verbal, and motor deficits. The severity of watershed injury is correlated with later intellectual performance. Long-term follow-up examinations are necessary for early detection of neurodevelopmental impairment and early initiation of adequate therapies.

Development of neuromotor functions in very low birth weight children from six to 10 years of age: patterns of change.

AIM: To assess patterns of change for different neuromotor functions in very low birth weight (VLBW) children during school age and to identify factors associated with improvement. METHODS: In a longitudinal study, we examined 65 prospectively enrolled VLBW children (38 female, 59%) without cerebral palsy at age six and 10 years. Measures included the evaluation of timed motor performance and motor overflow (MO) for the motor components of the Zurich Neuromotor Assessment (pure motor-, adaptive fine- and gross motor tasks, static balance) and a standardized neurological examination. Variables associated with improvement were assessed by multiple regression analyses. RESULTS: Between six and 10 years, adaptive fine motor tasks (40% vs. 17% of children scoring below 10th percentile) and MO (77% vs. 55%) improved significantly (both p<0.01), while all other components remained stable (pure motor 23% vs. 25%, adaptive gross motor 26% vs. 34%, static balance 18% vs. 20%, respectively). Mild neurological abnormalities at 6 years of age were associated with less improvement. CONCLUSION: Neuromotor functions improve in some children potentially reflecting catch up of maturational delay. However, the majority of neuromotor functions remain abnormal in a significant proportion of VLBW children.

Cardiac rhythm devices in pediatric patients: Impact on family functioning and parent's health-related quality of life.

This study compares the impact of children's cardiac rhythm devices and health status on their parents with that of healthy controls. Furthermore, it aims to ascertain whether sociodemographic characteristics and medical data are associated with parent-reported impacts. This cross-sectional study is part of a comprehensive single-center study of long-term psychosocial outcomes in pediatric patients with pacemakers and implantable cardioverter defibrillators. The study includes 69 patients with their parents: 69 mothers and 57 fathers. Parents responded to the Pediatric Quality of Life Inventory Family Impact Module and to open-ended questions assessing impact on family life and treatment satisfaction. Parents reported more negative impact on family life than healthy controls in all three summary scores. Among fathers, presence of a child's congenital heart disease and female sex is associated with lower family function. No group differences emerged regarding device type. Positive and negative cognitive aspects predominated for patients' mothers and fathers. However, one substantial difference is that mothers reported more positive and negative emotional impact than fathers. We conclude that parents' well-being should be addressed in clinical contexts, especially through emotional and practical support and open communication focused on parents' worries and concerns.

A psychological intervention for caries active young adults, a randomized controlled trial.

OBJECTIVE: The aim of the present study was to evaluate the effect of a brief version of the behavioral intervention Acceptance and Commitment Therapy (ACT) on reducing gingivitis and plaque levels after 18 weeks. MATERIALS AND METHODS: One hundred thirty-five caries-active young adults (18-25 years of age), recruited from two public dental clinics, participated in this parallel group randomized control trial (RCT). Participants in the intervention (n = 67) received two ACT sessions in combination with standard information on oral health, and participants allocated to the control group (n = 68) received standard information only. Gingivitis and plaque levels were recorded at baseline and at the 9- and 18-week follow-ups. The effect of the intervention versus standard information alone was analyzed by intention-to-treat and per protocol, applying the General Linear Model (GLM). Exploratory analyses for the intervention and control groups were conducted to evaluate the effect of gender and smoking habits on the gingivitis and plaque outcome. The CONSORT guidelines for RCT were followed. RESULTS: A significant decrease in gingivitis and plaque levels was observed over time, irrespective of treatment allocation. However, the ACT intervention was not significantly more effective at reducing gingivitis and plaque scores than standard information alone, even though the intervention participants had maintained their improvement to a greater extent. The exploratory analysis revealed that females improved their gingivitis and plaque levels significantly more than the males in the intervention group (p = 0.025 for gingivitis and p = 0.013 for plaque). CONCLUSION: A brief ACT intervention was not proven to be more effective than standard information alone at improving oral health in a sample of young adults with poor oral health. However, ACT seems to have a positive effect on oral health among females. (TRN ISRCTN15009620).

Sleep and Health-Related Characteristics among Adolescents during COVID-19: An Update.

Two opposing effects on adolescents' health during COVID-19 lockdown have been described: A beneficial one due to longer sleep times during school closures and a detrimental one of psychological distress. This study investigated how sleep and health changed in the course of the pandemic when schools were open again. Overall, 12,238 adolescents in Switzerland participated in three cross-sectional online surveys: In 2017 under regular conditions (control group), during pandemic school closures in 2020 (closure group), and in 2021 still under pandemic conditions, but schools were open again (postclosure group). Sleep behavior and health-related characteristics (health-related quality of life; caffeine, alcohol, and nicotine use) in all three groups and depressive symptoms in the closure and postclosure groups were assessed. The sleep period on school days was longer in the closure group (median 9.00 h, interquartile range 8.25-9.75) and similar in the postclosure (7.92, 7.00-8.50) compared to the control group (7.75, 7.08-8.33). Health-related characteristics were better during school closures and similar to worse in the postclosure compared to the control group. Depressive symptom levels were higher in the postclosure than in the closure group. Therefore, beneficial effects were specific to school closures and adolescents' psychological distress increased over the course of the pandemic.

Association Between Homeschooling and Adolescent Sleep Duration and Health During COVID-19 Pandemic High School Closures.

Importance: Although negative associations of COVID-19 pandemic high school closures with adolescents' health have been demonstrated repeatedly, some research has reported a beneficial association of these closures with adolescents' sleep. The present study was, to our knowledge, the first to combine both perspectives. Objective: To investigate associations between adolescents' sleep and health-related characteristics during COVID-19 pandemic school closures in Switzerland. Design, Setting, and Participants: This survey study used cross-sectional online surveys circulated among the students of 21 public high schools in Zurich, Switzerland. The control sample completed the survey under regular, prepandemic conditions (May to July 2017) and the lockdown sample during school closures (May to June 2020). Survey respondents were included in the study if they provided their sex, age, and school. Exposures: High school closures during the first COVID-19 pandemic wave in Switzerland (March 13 to June 6, 2020). Main Outcomes and Measures: Sleep-wake patterns, health-related quality of life (HRQoL, assessed by the KIDSCREEN-10 questionnaire), substance use (caffeine, alcohol, and nicotine), and depressive symptoms (lockdown sample only; assessed using the withdrawn/depressed scale from the Youth Self Report). Multilevel regression models were used to assess sample differences and associations of health-related characteristics with sleep duration and depressive symptoms. Results: The total sample consisted of 8972 students, including 5308 (59.2%) in the control sample (3454 [65.1%] female) and 3664 (40.8%) in the lockdown sample (2429 [66.3%] female); the median age in both samples was 16 years (IQR, 15-17 years). During school closures, the sleep period on scheduled days was 75 minutes longer (semipartial R2 statistic [R2ß*], 0.238; 95% CI, 0.222-0.254; P < .001) and the students had better HRQoL (R2ß*, 0.007; 95% CI, 0.004-0.012; P < .001) and less consumption of caffeine (R2ß*, 0.010; 95% CI, 0.006-0.015; P < .001) and alcohol (R2ß*, 0.014; 95% CI, 0.008-0.022; P < .001). Longer sleep duration was associated with better HRQoL (R2ß*, 0.027; 95% CI, 0.020-0.034; P < .001) and less caffeine consumption (R2ß*, 0.013; 95% CI, 0.009-0.019; P < .001). In the lockdown sample, an inverse association was found between depressive symptoms and HRQoL (R2ß*, 0.285; 95% CI, 0.260-.0311; P < .001) and a positive association was found with caffeine consumption (R2ß*, 0.003; 95% CI, 0.000-0.008; P = .01). Conclusions and Relevance: In this survey study, 2 opposing associations between school closures and adolescents' health were identified: a negative association with psychological distress and a beneficial association with increased sleep duration. These findings should be considered when evaluating and implementing school closures. Furthermore, the findings provide support for delaying school start times for adolescents.