Association of Delaying School Start Time With Sleep Duration, Timing, and Quality Among Adolescents

Solar clock and school start time effects on adolescents' chronotype and sleep: A review of a gap in the literature

Circadian rhythms are entrained by external factors such as sunlight and social cues, but also depend on internal factors such as age. Adolescents exhibit late chronotypes, but worldwide school starts early in the morning leading to unhealthy sleep habits. Several studies reported that adolescents benefit from later school start times. However, the effect of later school start time on different outcomes varies between studies, and most previous literature only takes into consideration the social clock (i.e. local time of school starting time) but not the solar clock (e.g. the distance between school start time and sunrise). Thus, there is an important gap in the literature: when assessing the effect of a school start time on chronotype and sleep of adolescents at different locations and/or seasons, the solar clock might differ and, consistently, the obtained results. For example, the earliest school start time for adolescents has been suggested to be 08:30 hours, but this school start time might correspond to different solar times at different times of the year, longitudes and latitudes. Here, we describe the available literature comparing different school start times, considering important factors such as geographic position, nationality, and the local school start time and its distance to sunrise. Then, we described and contrasted the relative role of both social and solar clocks on the chronotype and sleep of adolescents. As a whole, we point and discuss a gap in literature, suggesting that both clocks are relevant when addressing the effect of school start time on adolescents' chronotype and sleep.

Co-design personal sleep health technology for and with university students

University students often experience sleep disturbances and disorders. Personal digital technologies present a great opportunity for sleep health promotion targeting this population. However, studies that engage university students in designing and implementing digital sleep health technologies are scarce. This study sought to understand how we could build digital sleep health technologies that meet the needs of university students through a co-design process. We conducted three co-design workshops with 51 university students to identify design opportunities and to generate features for sleep health apps through workshop activities. The generated ideas were organized using the stage-based model of self-tracking so that our findings could be well-situated within the context of personal health informatics. Our findings contribute new design opportunities for sleep health technologies targeting university students along the dimensions of sleep environment optimization, online community, gamification, generative AI, materializing sleep with learning, and personalization.

Substituting Book Reading for Screen Time Benefits Preschoolers' Sleep Health: Results from the Ulm SPATZ Health Study

Purpose

Healthy sleep is essential for the physical, cognitive, and social development of children. Several studies have reported the increase in digital media use in preschool children and its association with impaired sleep. However, there is relatively little evidence on the effects of book reading as a potentially safe alternative. The objective of this study, therefore, was to investigate whether sleep in children could benefit from book reading, and whether the negative effects of media use on sleep can be mitigated by substituting book reading for screen time.

Participants and Methods

We used longitudinal data from three consecutive waves of the SPATZ Health study, including children at the ages of 4 (n=581), 5 (n=508), and 6 (n=426) years. All data were collected by self-administered questionnaires. Parent-reported child sleep was assessed by the Children's Sleep Habits Questionnaire.

Results

Across the three waves, screen-based media use increased and was associated with lower sleep quality. In contrast, the time spent with book reading decreased; however, book reading appeared to be beneficial for children's sleep. Substitution models revealed that the theoretical substitution of an equal amount of book reading for 50% of the time spent with screen-based media benefits several domains of preschoolers' sleep health, including parasomnias, sleep anxiety, daytime sleepiness, and sleep onset delay.

Conclusion

Besides implications for population-wide and individual prevention, book reading may also be incorporated as a useful intervention to improve sleep quality in children who are already affected by sleep problems. Given that book reading is perceived as a safe alternative, the presented evidence may suffice to support recommendations in this direction.

Childhood sleep: physical, cognitive, and behavioral consequences and implications

BACKGROUND

Sleep problems in children have been increasingly recognized as a major public health issue. Previous research has extensively studied and presented many risk factors and potential mechanisms for children's sleep problems. In this paper, we aimed to identify and summarize the consequences and implications of child sleep problems.

DATA SOURCES

A comprehensive search for relevant English language full-text, peer-reviewed publications was performed focusing on pediatric sleep studies from prenatal to childhood and adolescence in a variety of indexes in PubMed, SCOPUS, and Psych Info published in the past two decades. Both relevant data-based articles and systematic reviews are included.

RESULTS

Many adverse consequences are associated with child sleep deficiency and other sleep problems, including physical outcomes (e.g., obesity), neurocognitive outcomes (e.g., memory and attention, intelligence, academic performance), and emotional and behavioral outcomes (e.g., internalizing/externalizing behaviors, behavioral disorders). Current prevention and intervention approaches to address childhood sleep problems include nutrition, exercise, cognitive-behavioral therapy for insomnia, aromatherapy, acupressure, and mindfulness. These interventions may be particularly important in the context of coronavirus disease 2019. Specific research and policy strategies can target the risk factors of child sleep as well as the efficacy and accessibility of treatments.

CONCLUSIONS

Given the increasing prevalence of child sleep problems, which have been shown to affect children's physical and neurobehavioral wellbeing, understanding the multi-aspect consequences and intervention programs for childhood sleep is important to inform future research direction as well as a public health practice for sleep screening and intervention, thus improving sleep-related child development and health.

Associations between sleep habits, quality, chronotype and depression in a large cross-sectional sample of Swedish adolescents

OBJECTIVE

To investigate behavioral sleep habits, self-perceived quality of sleep, and chronotype, and to examine their association with clinically relevant levels of depression in Swedish adolescents.

METHOD

Questionnaire data were obtained from a representative sample of Swedish adolescents (n = 8449; 50.8% girls; aged 12-16). Depression was defined as >13 BDI-II scores. Logistic regression modelling estimated the effects of sleep duration, sleep quality, and chronotype on depression, adjusted for socio-demographic factors.

RESULTS

On weekdays, approximately 46% of adolescents slept less than the recommended length of eight hours per night (depressed: 68%, non-depressed: 40%). On weekends, however, only 17% slept shorter than recommended. Short weekday sleep duration was more common among girls than boys (53% vs. 38%) and girls reported worse sleep quality. The regression model showed that depression was predicted by weekday sleep duration (OR = 0.773, p < .0001), sleep quality (OR = 0.327, p < .0001), and late chronotype (OR = 1.126, p = .0017), but not by weekend sleep duration. A 30-minute increase in weekday sleep duration was associated with about 10% lower odds of depression.

CONCLUSIONS

A substantial proportion of Swedish adolescents do not seem to meet the sleep recommendations of eight hours per night. Short sleep duration on weekdays, poor sleep quality, and late chronotype were associated with increased risk of depression. Interventions promoting longer weekday sleep duration (e.g., later school start times) seem relevant in this context, but further research is needed to investigate the directionality and underlying mechanisms of these associations.

Sleep Testing and Mortality in a Propensity-matched Cohort of Patients with Chronic Obstructive Pulmonary Disease

Rationale: Many advocate the application of propensity-matching methods to real-world data to answer key questions around obstructive sleep apnea (OSA) management. One such question is whether identifying undiagnosed OSA impacts mortality in high-risk populations, such as those with chronic obstructive pulmonary disease (COPD). Objectives: Assess the association of sleep testing with mortality among patients with COPD and a high likelihood of undiagnosed OSA. Methods: We identified patients with COPD and a high likelihood of undiagnosed OSA. We then distinguished those receiving sleep testing within 90 days of index COPD encounters. We calculated propensity scores for testing based on 37 variables and compared long-term mortality in matched groups. In sensitivity analyses, we compared mortality using inverse propensity weighting and instrumental variable methods. We also compared the incidence of nonfatal events including adverse outcomes (hospitalizations and COPD exacerbations) and routine services that are regularly indicated in COPD (influenza vaccination and pulmonary function testing). We compared the incidence of each nonfatal event as a composite outcome with death and separately compared the marginal probability of each nonfatal event independently, with death as a competing risk. Results: Among 135,958 patients, 1,957 (1.4%) received sleep testing. We propensity matched all patients with sleep testing to an equal number without testing, achieving excellent balance on observed confounders, with standardized differences < 0.10. We observed lower mortality risk among patients with sleep testing (incidence rate ratio, 0.88; 95% confidence interval [CI], 0.79-0.99) and similar results using inverse propensity weighting and instrumental variable methods. Contrary to mortality, we found that sleep testing was associated with a similar or greater risk for nonfatal adverse events, including inpatient COPD exacerbations (subhazard ratio, 1.29; 95% CI, 1.02-1.62) and routine services like influenza vaccination (subhazard ratio, 1.26; 95% CI, 1.17-1.36). Conclusions: Our disparate findings can be interpreted in multiple ways. Sleep testing may indeed cause both reduced mortality and greater incidence of nonfatal adverse outcomes and routine services. However, it is also possible that our findings stem from residual confounding by patients' likelihood of accessing care. Given the limitations of propensity-based analyses, we cannot confidently distinguish these two possibilities. This uncertainty highlights the limitations of using propensity-based analyses to guide patient care and policy decisions.

Afternoon school shift is associated with increased risk of overweight/obesity in 11-14-year-old females with early and intermediate chronotype

OBJECTIVE

The purpose of this study was to compare the anthropometric and sleep-wake rhythm characteristics of schoolchildren that attend school in morning and afternoon school shifts.

METHODS

We recruited 18 481 individuals (females: 56.4%) aged 11 to 18 years old with an average age of 14.4 ± 1.7 years old. In total, 812 (4.2%) questionnaires were incomplete. The self-reported height and weight were used to assess the sex- and age-corrected body mass index of the participants. The Munich ChronoType Questionnaire was used to assess the chronotype, social jetlag, and sleep duration of the participants.

RESULTS

In total, 12.6% of the participants were affected by overweight or obesity. The overweight and obesity incidence rate was higher among the students studying in the afternoon (odd ratio [95%CI]: 1.33 [1.16-1.52]). The afternoon school shift had a negative impact on the anthropometric indicators only in the 11-14-year-olds (1.29 [1.11-1.50]) and girls (1.26 [1.04-1.54]) with an early (1.27 [1.03-1.56]) and intermediate (1.30 [1.07-1.58]) chronotype.

CONCLUSION

The data obtained indicated that the afternoon school shift is not ideal, especially for female children and adolescents under 15 years old with an early and intermediate chronotype.

Perspective: Teenagers and the sleep paradox

STUDY OBJECTIVES

Teenagers experience sleep deficits as they try to manage expectations with school, their social media presence, and increasingly competitive extracurriculars. Late-night screen time is a barrier to sleep hygiene. It is important to acknowledge and understand lifestyle challenges that can prevent teenagers from receiving adequate sleep every night. A teenager perspective on these issues and recommendations can incite better ways to outreach, educate, and support teenagers in maintaining good sleep.

METHODS

We describe what is known and not known about sleep health among teenagers and challenges to maintaining adequate sleep from the perspective of a third-year high school student. We also provide recommendations for outreach to promote early recognition of issues and tools that can support sleep hygiene to reinforce future mental and physical health.

RESULTS

While teenagers enjoy good sleep, this is limited by heavy loads of homework along with increasingly competitive extracurriculars, keeping up with social and cultural demands, and early school starts. Also, teenagers may not understand what adequate sleep entails and the full impact of sleep on well-being.

CONCLUSIONS

Social media provides a channel to extend outreach to teenagers to communicate the importance of consistent quality and quantity of sleep, increase awareness of sleep tracking tools, and highlight the impact of sleep on mental health. Additionally, better engagement is needed with schools and community to manage academic and extracurricular schedules that allow teenagers to schedule consistent bedtimes and wake times.

CITATION

Ramar S, Lloyd RM Perspective: teenagers and the sleep paradox. J Clin Sleep Med. 2023;19(8):1569-1571.

School-Based Sleep Education Program for Children: A Cluster Randomized Controlled Trial

Insufficient sleep contributes negatively to child developmental processes and neurocognitive abilities, which argues the need for implementing interventions to promote sleep health in children. In this study, we evaluated the effectiveness of a multimodal and multilevel school-based sleep education program in primary school children using a cluster randomized controlled design. Twelve schools were randomly assigned to either the sleep education or nonactive control groups. The sleep education group included a town hall seminar, small class teaching, leaflets, brochures, and a painting competition for children. Parents and teachers were invited to participate in a one-off sleep health workshop. Parental/caregiver-reported questionnaires were collected at baseline and 1-month follow-up. A total of 3769 children were included in the final analysis. There were no significant improvements observed in the sleep-wake patterns, daytime functioning, and insomnia symptoms between the two groups at follow-up, whereas the intervention group had significantly improved parental sleep knowledge than the controls (paternal: adjusted mean difference: 0.95 [95% confidence interval (CI): 0.18 to 1.71]; maternal: adjusted mean difference: 0.87 [95% CI: 0.17 to 1.57]). In addition, children receiving the intervention had a lower persistence rate of excessive beverage intake (adjusted odds ratio: 0.49 [95% CI: 0.33 to 0.73]), and experienced greater reductions in conduct problems (adjusted mean difference: 0.12 [95% CI: 0.01 to 0.24]) compared with the controls at 1-month of follow-up. Moreover, a marginally significant reduction for emotional problems in the intervention group was also observed (adjusted mean difference: 0.16 [95% CI: -0.00 to 0.32]). These findings demonstrated that school-based sleep education was effective in enhancing parental sleep knowledge and improving behavioral outcomes in children, but not sufficient in altering the children's sleep-wake patterns and sleep problems.

School start time delays and high school educational outcomes: Evidence from the START/LEARN study

INTRODUCTION

Delaying high school start times extends adolescents' nightly sleep, but it is less clear how it affects educational outcomes. We expect links between school start time delays and academic performance because getting enough sleep is a key input to the cognitive, health, and behavioral factors necessary for educational success. Thus, we evaluated how educational outcomes changed in the 2 years following a school start time delay.

METHODS

We analyzed 2153 adolescents (51% male, 49% female; mean age 15 at baseline) from START/LEARN, a cohort study of high school students in the Minneapolis-St. Paul, MN, USA metropolitan area. Adolescents experienced either a school start time delay ("policy change schools") or consistently early school start times ("comparison schools"). We compared patterns of late arrivals, absences, behavior referrals, and grade point average (GPA) 1 year before (baseline, 2015-2016) and 2 years after (follow-up 1, 2016-2017 and follow-up 2, 2017-2018) the policy change using a difference-in-differences analysis.

RESULTS

A school start time delay of 50-65 min led to three fewer late arrivals, one fewer absence, a 14% lower probability of behavior referral, and 0.07-0.17 higher GPA in policy change schools versus comparison schools. Effects were larger in the 2nd year of follow-up than in the 1st year of follow-up, and differences in absences and GPA emerged in the second year of follow-up only.

CONCLUSIONS

Delaying high school start times is a promising policy intervention not only for improving sleep and health but for improving adolescents' performance in school.

The impact of delayed school start time on adolescent beverage consumption, findings from the START study

OBJECTIVES

We sought to examine the effects of high school start time delay, a proven sleep-promoting intervention, on sugary beverage (SB) consumption among U.S. adolescents.

METHODS

In the Spring of 2016 (baseline), the START study recruited 2134 ninth grade students who were enrolled high schools in the Twin Cities, MN metropolitan area. These participants were surveyed again in their 10th and 11th grade years, in Spring 2017 and 2018 (follow-ups 1 and 2). All five high schools started early (7:30 or 7:45 a.m.) at baseline. By follow-up 1, two "policy change" schools shifted their start times later (8:20 or 8:50 a.m.) and maintained these later start times through follow-up 2 while three "comparison schools" retained an early start time at all time points. Generalized estimating equations using a negative binomial distribution were used to obtain estimates of the number of sugary beverages consumed per day at each wave as well as the difference in difference (DiD) estimates between baseline and each follow-up period comparing policy change to comparison schools.

RESULTS

Mean baseline sugary beverage consumption was 0.9 (1.5) beverages per day in policy change schools and 1.2 (1.7) beverages per day in the comparison schools. While there was no evidence of impact of start time change on total SB consumption, DiD estimates revealed a small decrease in the number of caffeinated sugary beverages consumed between baseline and the second follow-up period in students attending the policy change schools relative to comparison schools in both crude (0.11/day reduction, p-value = 0.048) and adjusted analyses (0.11/day reduction, p-value = 0.028).

CONCLUSION

Although the differences in this study were quite modest, a population-wide reduction in sugary beverage consumption could have public health benefit.

Impact of Changing School Start Times on Teacher Sleep Health and Daytime Functioning

BACKGROUND

The benefits of delaying school start times for secondary students are well-established. However, no previous study has considered how changing school start times impacts sleep and daytime functioning for K-12 teachers.

METHODS

Teachers in a large suburban school district completed 3 annual surveys (pre-change n = 1687, post-change n = 1857, follow-up n = 1812) assessing sleep and daytime functioning.

RESULTS

With delayed start times, high school teachers had later rise times (high school [HS]: 28 minutes, middle school [MS]: 14 minutes), increased sleep duration (HS: 22 minutes, MS: 13 minutes), and improved daytime functioning. Improvements for middle school teachers were noted but were not statistically significant. With earlier start times, elementary teachers reported earlier bedtimes (9 minutes) and wake times (9 minutes), with no changes in sleep duration or daytime functioning.

IMPLICATIONS FOR SCHOOL HEALTH POLICY, PRACTICE, AND EQUITY

Today's school health policies often focus on wellness. Findings from this study reveal that the policy of healthy school start times can have a significant, positive impact on adults who teach in later-starting secondary schools. Later school start times for secondary teachers provide greater parity with their elementary colleagues in terms of sleep opportunity.

CONCLUSIONS

This study extends previous findings on how the policy of later secondary school start times improves the health and well-being of adolescents, highlighting that healthy start times contribute to increased sleep opportunity for MS and HS teachers and improved daytime functioning for HS teachers, with changed start times having no significant negative effect on elementary school teachers.

[Sleepiness among adolescents: etiology and multiple consequences]

Over the past century a dramatic decline in sleep duration among adolescents, such as more than one hour of sleep loss per night, has been reported. A debt in sleep duration could lead to sleep deprivation, a major risk factor associated with daytime sleepiness. Sleepiness refers to the inability to maintain an adequate level of alertness during the day which may result in more or less being able to control falling asleep at inappropriate times. This literature review updates on sleepiness regarding its characteristics, etiology and consequences on adolescents. Studies revealed that from 25 % to 78 % of adolescents had reported sleepiness. Its manifestations may include heavy lids, yawns, difficulties to concentrate and emotional irritability. In addition, while it is recommended that adolescents under 18 years-old should sleep from eight to ten hours a night, only 63 % of them actually do so. The etiology of sleep deprivation and sleepiness in this population can be explained by various biological and societal factors. First, the sleep-wake cycle of adolescents shows a biological shift from the beginning of pubertal maturation, described as a perfect storm. It refers to a social jetlag by going to sleep and waking up later and accumulating a sleep debt during weekdays which they try to reimburse during weekends. This phenomenon can be explained by physiological changes such as a slower accumulation of sleep pressure. In addition to this perfect storm, environmental and societal factors contribute to the social jetlag and reduce sleep duration in adolescents. Screen exposure before bedtime can delay sleep and wake onset, which is a risk factor for sleeping debt. Substance use such as caffeine, cigarettes or electronic vaporizer, ADHD or freely available medication, alcohol, cannabis use or drug consumption could further disrupt sleep-wake cycle by stimulating, depressing or otherwise disrupting the central nervous system. Early, before 8:30 am, class start times have been associated with chronic sleep deprivation, higher level of sleepiness and delayed melatonin peak secretion. Adolescents working or doing extracurricular occupations for more than 20hours a week are more at risk for reduced sleep duration and sleepiness. Parental supervision about sleep during the weekdays were associated with more appropriate bedtime. Adolescents from low socio-demographic characteristics and from minority ethnic groups have reported displaying a shorter sleep duration. Finally, sleep disorders of a physiological origin such as narcolepsy, sleep apnea or restless legs syndrome, may explain the sleep deprivation and sleepiness. Sleep deprivation and sleepiness in adolescents have consequences on their health. Cognitive functioning, such as problem solving, attention or memory, as well as school performance, can be compromised by sleep deprivation and sleepiness. At the psychological level, adolescents reporting sleepiness are more prone to display mental health problems: associations were found between sleepiness and subjective perception of depression, anxiety, somatic complaints as well as with antisocial behaviors. Finally, 68 % of 16 year-old adolescents reported they drove a car, and the reported sleepiness could lead to road accidents due to reduced attentional functioning, reaction time and decision-making abilities. In the United-States, from 7 % to 16.5 % of deadly accidents were related to driving while drowsy. Highlighting etiology and problems associated with sleep deprivation and sleepiness in adolescents could guide researchers and clinicians towards the development of possible interventions. Public health measures and knowledge transfer programs regarding modifiable psychosocial and societal factors associated with sleep-wake bioregulation could increase awareness in parents as well as in political and societal decision makers.

Sleep Health Education to Promote Public Health: Attitudes and Desired Learning Goals among Social Work Students

Social workers are often front line behavioral health providers for underserved populations, many of whom experience sleep disturbances. Inadequate sleep presents a public health challenge and is associated with many adverse physical health and mental health consequences. Social workers are uniquely positioned to promote sleep health among individuals experiencing health inequities. However, sleep is rarely included as part of the curricula in social work programs in the U.S. We conducted qualitative formative research to investigate social work students' perceptions of sleep education and desired sleep learning objectives. Twenty-five social work students were recruited via a listserv e-mail to participate in one of three focus groups. Participants believed sleep education could be beneficial in promoting client health and well-being. Desired learning goals included: (1) the importance of sleep; (2) identify symptoms of sleep deprivation and sleep disorders; (3) environmental and lifestyle factors that impact sleep; (4) behaviors to promote optimal sleep; and (5) sleep health as it relates to special populations (e.g., homelessness, substance using). Social work students expressed a desire to aquire knowledge on sleep health promotion as part of the social work curricula. Sleep education could be of considerable relevance to social work students, practitioners, and the clients they serve.

Measuring Sleep Stages and Screening for Obstructive Sleep Apnea with a Wearable Multi-Sensor System in Comparison to Polysomnography

Objective

To assess the performance of a wearable multi-sensor system (SensEcho) in comparison to polysomnography (PSG) in measuring sleep stages and searching for obstructive sleep apnea (OSA).

Methods

Participants underwent overnight simultaneous monitoring using SensEcho and PSG in a sleep laboratory. SensEcho analyzed the recordings spontaneously, and PSG was assessed as per standard guidelines. The degree of snoring was evaluated according to the guidelines for the diagnosis and treatment of OSA hypopnea syndrome (2011 revision). The Epworth Sleepiness Scale (ESS) was used to assess general daytime sleepiness.

Results

This study included 103 Han Chinese, 91 of whom (age 39.02 ± 13.84 years, body mass index 27.28 ± 5.12 kg/m2, 61.54% male) completed the assessments. The measures of total sleep time (P = 0.198); total wake time (P = 0.182); shallow sleep (P = 0.297), deep sleep (P = 0.422), rapid eye movement sleep (P = 0.570), and awake (P = 0.336) proportions were similar between SensEcho and PSG. Using an apnea-hypopnea index (AHI) cutoff of ≥ 5 events/h, the SensEcho had 82.69% sensitivity and 89.74% specificity. Almost the same results were obtained at an AHI threshold of ≥ 15 events/h. Although the specificity increased to 94.67%, it decreased to 43.75% at an AHI cutoff of ≥ 30 events/h.

Conclusion

This study demonstrated that SensEcho can be used to evaluate sleep status and screen for OSA. Nevertheless, improving the accuracy of its assessment of severe OSA and further testing its effectiveness in community and home environments is necessary.

Child Eveningness as a Predictor of Parental Sleep

Child eveningness has been associated with many adverse outcomes for children. The aim of this study was to assess whether child eveningness poses a risk to parental sleep quality in follow-up. A total of 146 children (57% adopted, 47% boys, mean age at follow-up 5.1 years [standard deviation 1.7]) completed a 1-week actigraph recording to analyze their sleep twice, 1 year apart. The parents completed the Child ChronoType Questionnaire for their child and a short version of the Morningness-Eveningness Questionnaire for themselves and the Jenkins Sleep Scale for their sleep quality. Linear regression analyses showed that subjective parental sleeping problems at baseline were associated with subjective parental sleeping problems at follow-up. A morning-type child decreased the risk of parental sleeping problems at the 1-year follow-up compared to the child evening chronotype. Additionally, the child intermediate chronotype decreased the risk of maternal sleeping problems at the 1-year follow-up compared to the evening chronotype of the child. Parents of evening-type children experienced more sleeping problems in the follow-up, compared to parents of morning-type children. This finding encourages parents and professionals to steer the diurnal rhythm of evening-type children toward an earlier daily routine.

Adolescent sleep myths: Identifying false beliefs that impact adolescent sleep and well-being

OBJECTIVE

Commonly held beliefs about sleep unsupported by scientific evidence (ie, myths) among adolescents and their parents/caregivers may adversely influence sleep-related attitudes and behaviors among adolescents. Thus, identifying such myths with the goal of developing effective evidence-based counter-messages has the potential to improve sleep health in adolescents.

METHOD

We identified myths with a panel of adolescent sleep health experts (n = 12) using the Delphi method in three sequential steps: (1) focus groups; (2) online discussion; and (3) closed-ended questionnaires with which the experts rated myths on: (1) falseness and (2) public health significance using 5-point Likert scales ranging from 1 (not at all false/important for public health) to 5 (extremely false/important for public health). Next, we explored the prevalence of the myths among a demographically diverse sample of parents/caregivers of adolescents in the United States. Finally, we report the counterevidence to refute each myth.

RESULTS

Ten myths about adolescent sleep were identified by the experts using the Delphi method. The most prevalent myths were the beliefs that (1) "Going to bed and waking up late on the weekends is no big deal for adolescents, as long as they get enough sleep during that time," reported by 74% of parents/caregivers; (2) "If school starts later, adolescents will stay up that much later," reported by 69% of parents/caregivers; and (3) "Melatonin supplements are safe for adolescents because they are natural," reported by 66% of parents/caregivers.

CONCLUSION

Parents/caregivers have the potential to serve as sleep health advocates for their adolescent and support their adolescent's sleep health behaviors. Our study found that many parents/caregivers endorse myths about adolescent sleep that may hinder their ability to support their adolescent's sleep health. Future research may explore methods for promoting evidence-based beliefs about adolescent sleep among parents/caregivers.

A Naturalistic Actigraphic Assessment of Changes in Adolescent Sleep, Light Exposure, and Activity Before and During COVID-19

The majority of high school-aged adolescents obtain less than the recommended amount of sleep per night, in part because of imposed early school start times. Utilizing a naturalistic design, the present study evaluated changes in objective measurements of sleep, light, and physical activity before (baseline) and during the first wave of the COVID-19 pandemic (during COVID-19) in a group of US adolescents. Sixteen adolescents (aged 15.9 ± 1.2 years, 68.8% female) wore an actigraphy monitor for 7 consecutive days during an in-person week of school before the pandemic (October 2018-February 2020) and again during the pandemic when instruction was performed virtually (May 2020). Delayed weekday sleep onset times of 1.66 ± 1.33 h (p < 0.001) and increased sleep duration of 1 ± 0.87 h (p < 0.001) were observed during COVID-19 compared with baseline. Average lux was significantly higher during COVID-19 compared with baseline (p < 0.001). Weekday physical activity parameters were not altered during COVID-19 compared with baseline, except for a delay in the midpoint of the least active 5 h (p value = 0.044). This analysis provides insight into how introducing flexibility into the traditional school schedule might influence sleep in adolescents.

Nonpharmacological Interventions to Lengthen Sleep Duration in Healthy Children: A Systematic Review and Meta-analysis

Importance

Adequate sleep duration is necessary for many aspects of child health, development, and well-being, yet sleep durations for children are declining, and effective strategies to increase sleep in healthy children remain to be elucidated.

Objective

To determine whether nonpharmaceutical interventions to improve sleep duration in healthy children are effective and to identify the key components of these interventions.

Data Sources

CENTRAL, MEDLINE, Embase, PsycINFO, Web of Science Core collection, ClinicalTrials.gov, and WHO trials databases were searched from inception to November 15, 2021.

Study Selection

Randomized clinical trials of interventions to improve sleep duration in healthy children were independently screened by 2 researchers. A total of 28 478 studies were identified.

Data Extraction and Synthesis

Data were processed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) reporting guideline. Random-effects meta-analytic models were used to estimate pooled effect sizes.

Main Outcomes and Measures

Difference in sleep duration, measured in minutes.

Results

A total of 13 539 child participants from 45 randomized clinical trials were included. Of these, 6897 (50.9%) were in the intervention group and 6642 (49.1%) in the control group, and the mean age ranged from 18 months to 19 years. Pooled results indicate that sleep interventions were associated with 10.5 minutes (95% CI, 5.6-15.4) longer nocturnal sleep duration. There was substantial variation between trials. Sources of variation that were not associated with the study effect size included age group, whether the population was identified as having a sleep problem or being at a socioeconomic disadvantage (eg, coming from a low-income family or area), method of assessment of sleep duration (objective vs subjective), location of intervention delivery (home vs school), whether interventions were delivered in person or used parental involvement, whether behavioral theory was used, environmental change, or had greater or lower intensity. Interventions that included earlier bedtimes were associated with a 47-minute sleep extension (95% CI, 18.9-75.0; 3 trials) compared with remaining studies (7.4 minutes; 95% CI, 2.9-11.8; 42 trials) (P = .006 for group difference). Trials of shorter duration (6 months or less) had larger effects.

Conclusions and Relevance

Interventions focused on earlier bedtimes may offer a simple, pragmatic, effective way to meaningfully increase sleep duration that could have important benefits for child health.

Actigraphy-Based Sleep Detection: Validation with Polysomnography and Comparison of Performance for Nighttime and Daytime Sleep During Simulated Shift Work

Purpose

Actigraphy-based sleep detection algorithms were mostly validated using nighttime sleep, and their performance in detecting daytime sleep is unclear. We evaluated and compared the performance of Actiware and the Cole-Kripke algorithm (C-K) - two commonly used actigraphy-based algorithms - in detecting daytime and nighttime sleep.

Participants and Methods

Twenty-five healthy young adults were monitored by polysomnography and actigraphy during two in-lab protocols with scheduled nighttime and/or daytime sleep (within-subject design). Mixed-effect models were conducted to compare the sensitivity, specificity, and F1 score (a less-biased measure of accuracy) of Actiware (with low/medium/high threshold setting, separately) and C-K in detecting sleep epochs from actigraphy recordings during nighttime/daytime. t-tests and intraclass correlation coefficients were used to assess the agreement between actigraphy-based algorithms and polysomnography in scoring total sleep time (TST).

Results

Sensitivity was similar between nighttime (Actiware: 0.93-0.99 across threshold settings; C-K: 0.61) and daytime sleep (Actiware: 0.93-0.99; C-K: 0.66) for both the C-K and Actiware (daytime/nighttime×algorithm interaction: p > 0.1). Specificity for daytime sleep was lower (Actiware: 0.35-0.54; C-K: 0.91) than that for nighttime sleep (Actiware: 0.37-0.62; C-K: 0.93; p = 0.001). Specificity was also higher for C-K than Actiware (p < 0.001), with no daytime/nighttime×algorithm interaction (p > 0.1). C-K had lower F1 (nighttime = 0.74; daytime = 0.77) than Actiware (nighttime = 0.95-0.98; daytime = 0.90-0.91) for both nighttime and daytime sleep (all p < 0.05). The daytime-nighttime difference in F1 was opposite for Actiware (daytime: 0.90-0.91; nighttime: 0.95-0.98) and C-K (daytime: 0.77; nighttime: 0.74; interaction p = 0.003). Bias in TST was lowest in Actiware (with medium-threshold) for nighttime sleep (underestimation of 5.99 min/8h) and in Actiware (with low-threshold) for daytime sleep (overestimation of 17.75 min/8h).

Conclusion

Daytime/nighttime sleep affected specificity and F1 but not sensitivity of actigraphy-based sleep scoring. Overall, Actiware performed better than the C-K algorithm. Actiware with medium-threshold was the least biased in estimating nighttime TST, and Actiware with low-threshold was the least biased in estimating daytime TST.

Later school start time is associated with better academic performance, sleep-wake rhythm characteristics, and eating behavior

There are numerous studies which show that an early school start time has a negative impact on the sleep, well-being, and academic performance of students. There is not enough information on the association between school start time and eating disorders, however: the disruption of the circadian rhythm is known to be a risk factor for eating disorders. The aim of this study is to analyze the relationship between school start time (SST) and the sleep, well-being, academic performance, and eating behavior of children and adolescents. The study was conducted in April and May 2021 in two regions of Russia: the Komi Republic and Yekaterinburg. The online study involved the anonymous and voluntary participation of 6571 students in grades 6-11 (mean age: 14.5 ± 1.6 years, 60.1% female), who have morning classes. All participants were divided into three groups according to SST: 08:00 (n = 3661), 08:30 (n = 2020), and 09:00 (n = 890). Each participant of the study indicated their place of residence, SST, age, sex, height, weight, academic performance, and filled out the Munich Chronotype Questionnaire, the Zung Self-Rating Depression Scale, and the Yale Food Addiction Scale for Children. As a result of multiple regression analysis, it was shown that schoolchildren with SST of 09:00 wake up at a later time on school days (B = 0.432; ΔR² = 0.039), sleep more (B = 0.293; ΔR² = 0.004), have less pronounced social jetlag (B = -0.223; ΔR² = 0.005) and sleep loss (B = -0.292; ΔR² = 0.005), and higher academic performance (B = 0.113; ΔR² = 0.003) than schoolchildren with SST of 08:00. As a result of logistic regression analysis, it was found that the frequency of the detection of food addiction is ~30% lower in schoolchildren with SST of 09:00 (OR = 0.690; 95% CI = 0.485-0.981) than in their peers with SST of 08:00. Thus, an overly early SST in Russia has a negative impact on the sleep function, academic performance, and eating behavior of children and adolescents.

Sleep duration trajectory during the transition to adolescence and subsequent risk of non-suicidal self-harm

Non-suicidal self-harm (NSSH) and chronic insufficient sleep are both major health problems during the transition from childhood to adolescence. We examined to identify sleep duration trajectories from childhood to adolescence and their associations with subsequent risk of NSSH. A cohort of children around the period of pubertal onset (7-9 years old) were followed from 2013 over 6 years. Group-based trajectory modeling was recruited to identify sleep duration trajectories derived from 5 repeated measures. Association between sleep duration trajectories with the risk of NSSH was examined using multivariate logistic regression model. Nonlinear dose-response associations between sleep duration and NSSH risk were also assessed using restricted cubic spline models. Of the 1973 participants included in the study (mean ± SD, 8.1 ± 0.9 years age at baseline, 41.1% female). Three sleep duration trajectories were identified: persistent sleeping ≥ 8 h/day (27.7%), moderately decreasing (60.8%) and rapidly decreasing (11.5%) sleep duration groups. After multivariable adjustment for covariates, compared with the persistent sleeping ≥ 8 h/day group, the odds ratio of NSSH was 2.58 (95% CI 1.92, 3.45) for the moderately decreasing group, and 4.16 (2.86, 6.04) for rapidly decreasing group. In dose-response analysis, sleep duration was associated with NSSH risk in a non-linear fashion (χ² = 25.16, P_nonlinearity < 0.001). When compared with the reference (sleep duration = 8 h), the ORs (95% CI) for NSSH risks were 3.20 (1.93, 5.29), 2.37 (1.64, 3.41), 1.75 (1.39, 2.20) and 1.30 (1.18, 1.44) for sleep duration at 4 to 7 h, respectively. Also, we found sleep duration at 9 h [0.82 (0.75, 0.89)] and at 10 h [0.72 (0.57, 0.91)] significantly associated with decreased risk of NSSH. Longitudinal sleep duration patterns may assist in identification of adolescents at greatest risk of NSSH in the future, which could lead to improved targeting of prevention and intervention strategies. The findings also highlight a non-linear relationship between sleep duration and NSSH during the transition to adolescence.

Multiple positive outcomes of a later school starting time for adolescents

OBJECTIVE

We tested the effect of later school start time (LSST) by 1 hour during 1 week on sleep, sleepiness, and mood profile using within-subject design.

DESIGN

A within-subject 3-weeks-long interventional study. A baseline week with school starting at 7:30 AM (week A), followed by an intervention week with school starting at 8:30 AM (week B), and a recovery week with school start time back to 7:30 AM (week C). Mixed model for repeated measures analysis was applied to test for the LSST effect between weeks.

SETTING

A private high school with high level of socioeconomic status.

PARTICIPANTS

Forty-eight adolescents from 3 different high school years.

MEASUREMENTS

Participants were invited to wear actigraphs continuously during the 3 experimental weeks. Somnolence was obtained every school day twice, at arrival and before departure of school. Sleep quality and mood profile were evaluated by standard measures by the end of each school week, resulting in 3 repeated measures for each variable.

RESULTS

Thirty-eight adolescents completed the study. Adolescents woke up later during week B (7:42 ± 00:30) in comparison to weeks A (6:54 ± 00:12) and C (6:46 ± 00:15) (p < .001), with no significant change on sleep onset between weeks (p = .657), resulting in a longer sleep duration in week B (p < .001). Significant improvements on sleepiness and mood profile were also reported during week B.

CONCLUSIONS

Starting school later was effective in improving multiple aspects from sleep patterns, subjective sleepiness, and mood profile.

Sleep duration, depressive symptoms, and digital self-harm among adolescents

BACKGROUND

This study examines the relationship between sleep duration, depression, and engagement in a novel cyber behavior, digital self-harm, among adolescents.

METHOD

Logistic regression analyses were conducted using cross-sectional data from the 2019 Florida Youth Substance Abuse Survey (N = 9,819; 48% male; avg. grade level = 9th grade [SD = 1.9]) to analyze the association between sleep duration and digital self-harm. A Karlson-Holm-Breen (KHB) analysis was used to assess whether depressive symptoms attenuate this association.

RESULTS

Bivariate results indicated that longer sleep duration was associated with lower incidence of digital self-harm. Multivariate results showed that sleep duration was inversely associated with engaging in digital self-harm, net of all covariates. Depressive symptoms attenuated the influence of sleep duration on digital self-harm by 50.72%.

CONCLUSIONS

Both insufficient sleep and depressive symptoms were associated with engagement in digital self-harm among adolescents. Prospective research is needed, however, to confirm this pathway. Practitioners and clinicians should consider discussing digital self-harm with adolescents and parents, especially if adolescents are experiencing poor sleep and depressive symptoms.

A 4-year longitudinal study investigating the relationship between flexible school starts and grades

The mismatch between teenagers’ late sleep phase and early school start times results in acute and chronic sleep reductions. This is not only harmful for learning but may reduce career prospects and widen social inequalities. Delaying school start times has been shown to improve sleep at least short-term but whether this translates to better achievement is unresolved. Here, we studied whether 0.5–1.5 years of exposure to a flexible school start system, with the daily choice of an 8 AM or 8:50 AM-start, allowed secondary school students (n = 63–157, 14–21 years) to improve their quarterly school grades in a 4-year longitudinal pre-post design. We investigated whether sleep, changes in sleep or frequency of later starts predicted grade improvements. Mixed model regressions with 5111–16,724 official grades as outcomes did not indicate grade improvements in the flexible system per se or with observed sleep variables nor their changes—the covariates academic quarter, discipline and grade level had a greater effect in our sample. Importantly, our finding that intermittent sleep benefits did not translate into detectable grade changes does not preclude improvements in learning and cognition in our sample. However, it highlights that grades are likely suboptimal to evaluate timetabling interventions despite their importance for future success.

Sleep improvements on days with later school starts persist after 1 year in a flexible start system

Early school times fundamentally clash with the late sleep of teenagers. This mismatch results in chronic sleep deprivation posing acute and long-term health risks and impairing students' learning. Despite immediate short-term benefits for sleep, the long-term effects of later starts remain unresolved. In a pre-post design over 1 year, we studied a unique flexible school start system, in which 10–12th grade students chose daily between an 8:00 or 8:50AM-start. Missed study time (8:00–8:50) was compensated for during gap periods or after classes. Based on 2 waves (6–9 weeks of sleep diary each), we found that students maintained their ~ 1-h-sleep gain on later days, longitudinally (n = 28) and cross-sectionally (n = 79). This gain was independent of chronotype and frequency of later starts but attenuated for boys after 1 year. Students showed persistently better sleep quality and reduced alarm-driven waking and reported psychological benefits (n = 93) like improved motivation, concentration, and study quality on later days. Nonetheless, students chose later starts only infrequently (median 2 days/week), precluding detectable sleep extensions in the flexible system overall. Reasons for not choosing late starts were the need to make up lost study time, preference for extra study time and transport issues. Whether flexible systems constitute an appealing alternative to fixed delays given possible circadian and psychological advantages warrants further investigation.

Adolescent sleep health and school start times: Setting the research agenda for California and beyond: A research summit summary: A research summit summary

In fall 2019, California passed and signed into law SB328, the first US statewide legislation explicitly designed to protect adolescent sleep health by requiring most California public school districts to start no earlier than 8:00 AM for middle schools and 8:30 AM for high schools. Recognizing the unique opportunity presented by the bill's 3-year implementation period, a group of experts in adolescent sleep and school start times held a virtual summit on January 22-23, 2021 to (1) summarize the research on adolescent sleep and school start time change; (2) develop recommendations for relevant, refined, and innovative research areas and research questions; (3) provide input regarding research design, methodology, and implementation; and (4) offer a forum for networking, exchanging ideas, and establishing interdisciplinary research collaborations. Participants represented a multidisciplinary range of academic backgrounds including sleep and circadian biology, neuroscience, education, medicine, public health, mental health, safety, public policy, economics, implementation science, criminology, diversity studies, and science communication. This paper summarizes summit presentations regarding current knowledge on adolescent sleep health and school start times and key research recommendations from small group workshops on topics including research design and tools, methodological issues, sleep health disparities, logistical challenges in conducting school-based research, public-health impact, and novel and expanded approaches to research.

Association of Delaying School Start Time With Sleep-Wake Behaviors Among Adolescents

PURPOSE

Few adolescents spend enough time asleep on school nights. This problem could be addressed by delaying high school start times, but does this translate to reduced prevalence of sleep-wake problems like awakening too early or feeling sleepy during the day?

METHODS

The START study (n = 2,414) followed a cohort of students from five Minnesota high schools to evaluate impacts of school start time delays. Participants were enrolled in ninth grade (Baseline) when all schools started early (7:30 or 7:45 a.m.). At Follow-Up 1 (10th grade) and Follow-Up 2 (11th grade), two schools had delayed their start times by 50 and 65 minutes while three comparison schools started at 7:30 a.m. Six sleep-wake behaviors were assessed at all three time points via survey. Generalized estimating equation models were used to investigate changes in sleep-wake problems between policy change and comparison schools.

RESULTS

The prevalence of sleep-wake problems at Baseline ranged from 11% for being late to class due to oversleeping to 48% for needing to be told to wake multiple times in the morning. Compared to students from comparison schools, students at policy change schools reported smaller increases in the prevalence of feeling sleepy daily and oversleeping and being late to class between 9th and 11th grade. After implementation of the delayed start, awakening too early was more common among students at policy change schools compared to the comparison schools.

CONCLUSIONS

This longitudinal study provides evidence that delaying high school start times reduces daytime sleepiness and school tardiness.

Impact of changing school start times on parent sleep

OBJECTIVE

To examine the impact of changing school start times on sleep in parents of students in elementary, middle, and high school.

METHODS

Annual surveys were completed by parents of K-12 students (n = 8190-10,592 per year) before (pre-change) and for 2 years (post-change, follow-up) after implementation of new school start times (elementary school [ES]: 60 minutes earlier, middle school [MS]: 40-60 minutes later, high school [HS]: 70 minutes later), providing parent self-reported weekday bedtime and wake time, sleep quality, and feeling tired.

RESULTS

Significant level-by-year interactions were found for parent bedtime, wake time, and sleep duration (all p < .0001). Post hoc analyses show ES parents reporting earlier bedtimes and wake times at post-change, with no change in sleep duration, while MS and HS parents reported later post-change wake times. Post-change, more MS and HS parents reported sufficient sleep duration (p < .0001) and good sleep quality (p < .0001), with fewer HS parents reporting feeling tired (p < .0001).

CONCLUSIONS

This is the first study to consider the impact of a policy change aimed at improving child sleep on parent sleep. Healthy school start times has a significantly positive downstream effect on secondary school parents' sleep and daytime functioning, with minimal impact reported by parents of elementary school students.

Weekend night vs. school night sleep patterns, weight status, and weight-related behaviors among adolescents

OBJECTIVE

In this study, we examine associations between objectively measured weekend night vs. school night sleep patterns, weight status, and weight-related behaviors among adolescents.

DESIGN

Cross-sectional study.

SETTING

Five Minnesota high schools that started early (7:30 or 7:45 AM) in Spring 2016.

PARTICIPANTS

Ninth grade students, ages 14.5-16 years (n = 284).

MEASUREMENTS

Students completed surveys, had body measurements taken, and wore sleep (wrist) actigraphs for 1 week (n = 284). We examined weekend night-school night differences in sleep duration and sleep timing. We then assessed whether these factors were related to weight status and weight-related behaviors (eating behaviors, food consumption, physical activity, beverage consumption) using generalized linear mixed models.

RESULTS

On average, students slept 1.5 hours (95% confidence interval 1.3-1.7) more and had a sleep midpoint 1.9 hours (1.8-2.1) later on weekend nights compared to school nights. Female students had larger increases in sleep duration on weekend nights than males but similar timing differences. Sleep duration differences were uncorrelated with sleep timing differences (r = 0.01). Neither duration nor timing differences were associated with overweight, obesity, or any of the eating behaviors we examined. However, sleeping longer on weekend nights than on school nights was associated with lower probability of being active 6-7 days per week (p = .02).

CONCLUSIONS

Adolescents have substantial sleep duration and sleep timing differences on weekend nights vs. school nights. While these differences may not be associated with weight status or weight-related behaviors, they reflect the reality that most adolescents have schedules that restrict their sleep.

Relationship between Sleep Problems and Self-Injury: A Systematic Review

Objective/Background: Previous studies suggested that sleep problems were related to non-suicidal self-injury. The current systematic review investigated more thoroughly this relationship.Methods: PubMED and Embase databases were searched. The keywords were "self-injury" OR "self-harm" OR "non-suicidal self-injury" OR "self-injurious behavior" OR "self-destructive behavior" OR "self-mutilation" AND "sleep problem" OR "sleep disturbance" OR insomnia OR nightmare OR "poor sleep quality" or "sleep disorders." A total of 16 studies were included in the present review.Results: The pattern of results indicated that sleep problems such as short sleep duration, sleep disturbances, and poor sleep quality were associated with non-suicidal self-injury. Additionally, emotional dysregulation, depression, and post-traumatic stress disorder appeared to mediate this relationship. Above all adolescents and young adults with sleep disruptions were at higher risk of non-suicidal self-injury.Conclusions:g Interventions to improve sleep quality and sleep duration might concomitantly decrease the risk of non-suicidal self-injury.

Adolescent sleep duration and timing during early COVID-19 school closures

Objectives

To investigate adolescent sleep parameters and predictors during COVID-19-related school closures.

Methods

Original data were analyzed from a cross-sectional online survey of 590 teens in grades 6-12 attending school remotely in 35 US states, in May/June 2020.

Results

Students reported waking up 2.1-2.9 hours later during school closures and averaged 7.9-8.7 hours of sleep and 8.6-9.5 hours in bed on school nights. Compared to middle schoolers, high school students had later bed and wake times, accompanied by spending less time in bed and less time sleeping. The delay in wake time after school closures was also longer for high school students than for middle schoolers. Students with later class start times went to bed later, but also woke up later, slept longer, and spent more time in bed. When comparing intraindividual sleep before and after school closures, later class start times resulted in greater delays in wake time and greater odds of increased sleep duration. In addition, parent-set bedtimes were associated with earlier bedtimes and longer sleep duration during school closures.

Conclusions

As a result of COVID-19-related school closures and remote instruction, more middle and high school students achieved recommended amounts of sleep, primarily by waking up later in the morning. This study supports previous evidence that morning start schedule affects adolescent sleep behaviors. The implications of this study extend beyond COVID-19 school closures; adolescent sleep health improves with later school start times and fewer scheduled morning activities.

COVID-19 instructional approaches (in-person, online, hybrid), school start times, and sleep in over 5,000 U.S. adolescents

Study Objectives

To examine associations among instructional approaches, school start times, and sleep during the COVID-19 pandemic in a large, nationwide sample of U.S. adolescents.

Methods

Cross-sectional, anonymous self-report survey study of a community-dwelling sample of adolescents (grades 6–12), recruited through social media outlets in October/November 2020. Participants reported on instructional approach (in-person, online/synchronous, online/asynchronous) for each weekday (past week), school start times (in-person or online/synchronous days), and bedtimes (BT) and wake times (WT) for each identified school type and weekends/no school days. Sleep opportunity was calculated as BT-to-WT interval. Night-to-night sleep variability was calculated with mean square successive differences.

Results

Respondents included 5,245 racially and geographically diverse students (~50% female). BT and WT were earliest for in-person instruction; followed by online/synchronous days. Sleep opportunity was longer on individual nights students did not have scheduled instruction (>1.5 h longer for online/asynchronous than in-person). More students obtained sufficient sleep with later school start times. However, even with the same start times, more students with online/synchronous instruction obtained sufficient sleep than in-person instruction. Significantly greater night-to-night variability in sleep-wake patterns was observed for students with in-person hybrid schedules versus students with online/synchronous + asynchronous schedules.

Conclusions

These findings provide important insights regarding the association between instructional approach and school start times on the timing, amount, and variability of sleep in U.S. adolescents. Given the public health consequences of short and variable sleep in adolescents, results may be useful for education and health policy decision-making for post-pandemic secondary schools.

Changing school start times: impact on sleep in primary and secondary school students

STUDY OBJECTIVES

To examine the impact of changing school start times on sleep for primary (elementary school: ES) and secondary (middle and high school: MS/HS) students.

METHODS

Students (grades 3-12) and parents (grades K-12) were surveyed annually, before and for 2 years after school start time changes (ES: 60 min earlier, MS: 40-60 min later; HS: 70 min later). Student sleep and daytime sleepiness were measured with school-administered student surveys and parent-proxy online surveys.

RESULTS

Approximately 28,000 students annually completed surveys (~55% White, ~21% free/reduced lunch [FRL]). One-year post-change, weekday bedtimes and wake times were slightly earlier for ES students, with an 11-min decrease in sleep duration. MS and HS students reported slightly later weekday bedtimes, significantly later wake times, and significantly longer sleep duration (MS: 29 min; HS: 45 min). The percent of ES students reporting sufficient sleep duration, poor sleep quality, or daytime sleepiness did not change, but the percent of MS and HS students reporting sufficient sleep duration significantly increased and clinically significant daytime sleepiness decreased. All results were maintained at the 2-year follow-up. Benefits of later start times were similar across racial and free/reduced lunch groups.

CONCLUSIONS

This is the first large scale, longitudinal, and representative study to concurrently examine the impact of changing school start times across students in primary/secondary school. Findings suggest a minimal impact of earlier start times on ES students' sleep or daytime sleepiness, while further supporting the significant benefits of delaying MS and HS start times on student sleep and daytime sleepiness.

Lecture start time and sleep characteristics: Analysis of daily diaries of undergraduate students from the LoST-Sleep project

OBJECTIVES

Emerging evidence shows that later high school start times are associated with increased sleep duration; however, little is known if this extends to the university setting. This study investigated associations of first lecture start times with sleep characteristics among university students.

DESIGN

Daily diaries.

SETTING

Lincoln, UK.

PARTICIPANTS

One hundred and fifty-five undergraduate students completed 7-night sleep diaries MEASUREMENTS: Of the plausible lecture-day diaries (Monday-to-Friday, expected N = 755 days), 567 days were lecture days (M = 3.8 lecture-days per student, SD = 1.1). The Consensus Sleep Diary was used to collect sleep characteristics. Two-level multilevel mixed effect generalized linear models were employed in the analyses.

RESULTS

Seventy-five percent of first lectures occurred before noon. Students reported short sleep (M = 7.0 hours, SD = 1.9) and fewer reported highest levels of sleep quality (42.8%) and restfulness (24.8%) when first lectures started at 09:00 or 09:30 compared to 10:00 or later. Every hour delay of first lecture start time was associated with 15.1 (95% confidence interval [CI]: 9.5; 20.7) minutes increase in sleep duration and higher odds of reporting the highest levels of sleep quality and restfulness. Focusing on attended lectures starting before noon, hourly delay of first lecture start time was associated with 37.4 (95% CI: 22.0; 52.8) minutes increased sleep duration. Bedtime, sleep time, and sleep onset latency were not significantly associated with first lecture start times.

CONCLUSION

This study found that undergraduate students had longer sleep and healthier sleep quality when university first lectures started later. The earliest lecture start time that afforded sufficient sleep duration for students was 10:00.

Assessing Changes in Adolescents' Sleep Characteristics and Dietary Quality in the START Study, a Natural Experiment on Delayed School Start Time Policies

BACKGROUND

Sleep duration, quality, and timing may influence dietary quality. In adults, poor dietary quality is a risk factor for numerous chronic diseases. It is unclear how these various sleep domains influence adolescents' diets because prior population-based studies have not effectively manipulated sleep, did not include objective sleep measures, and had short follow-up times.

OBJECTIVES

The objectives of this study were to examine 1) how adolescent sleep characteristics relate to dietary quality; and 2) how delay in high school start times (which lengthened sleep duration) affects dietary quality over 2 y.

METHODS

In the START study, adolescents (grades 9-11, n = 423) attending 5 high schools in the Minneapolis, Minnesota metropolitan area were annually assessed in 3 waves (2016-2018). At Baseline, all schools started "early" (07:30 or 07:45). From Follow-up 1 through Follow-up 2, 2 "policy change schools" shifted to later start times (to 08:20 and 08:50). Three "comparison schools" maintained their early start throughout. Sleep characteristics were measured with actigraphy. Mixed-effect regression models were used to examine cross-sectional and longitudinal associations of sleep characteristics with dietary quality, and school start time policy change with dietary quality change.

RESULTS

Cross-sectionally, later sleep midpoint and onset were associated with dietary quality scores 1.6-1.7 lower (both P < 0.05). However, no prospective associations were observed between sleep characteristics and dietary quality in longitudinal models. Shifting to later school start time tended to be associated with a 2.4-point increase in dietary quality score (P = 0.09) at Follow-up 1, but was not associated with change in dietary quality scores at Follow-up 2 (P = 0.35).

CONCLUSIONS

High school students attending delayed-start schools maintained better dietary quality than students in comparison schools; however, differences were not statistically significant. Overall study findings highlight the complexity of the relation between sleep behavior and diet in adolescence.

Household chaos, family routines, and young child movement behaviors in the U.S. during the COVID-19 outbreak: a cross-sectional study

BACKGROUND

The home environment is an important facilitator of young child movement behaviors, including physical activity (PA), sleep, and screen-time. Household chaos, characterized by crowding, noise, and disorder in the home, may hinder efforts to obtain adequate amounts of movement behaviors. The COVID-19 outbreak impacted many families, and social distancing during this time may create conditions for more household chaos. Family routines can help establish order in the home and encourage an appropriate balance of movement behaviors, such as less screen-time and more sleep. The purpose of this study was to evaluate the association between household chaos and young child movement behaviors during the COVID-19 outbreak in the United States, and the role of family routines in this relationship.

METHODS

A national online survey including 1836 mothers of preschoolers (3.0-5.9 years) was conducted during May 2020. Mothers reported demographic characteristics, household chaos, family routines, and the preschooler's movement behaviors during the outbreak. Mothers completed a household chaos questionnaire and were grouped into chaos categories (low, moderate/low, moderate/high, and high) for analysis. Linear regression was used to assess the association between chaos category, family routines, and movement behaviors with adjustment for covariates.

RESULTS

Mothers were 35.9 ± 4.1 years of age, middle income (47.8%), and preschoolers were 3.8 ± 0.8 years of age. Most mothers reported their preschooler was less physically active (38.9%), slept the same amount of time (52.1%), and increased their screen-time (74.0%) after the COVID-19 outbreak. Preschoolers in the high chaos households performed less total PA (β = - 0.36 days/week, 95% CI:-0.62 to - 0.09, p = 0.008), slept less (β = - 0.42 h, 95% CI:-0.59 to - 0.25, p = 0.001) and had more screen-time (β = 0.69 h, 95% CI:0.45 to 0.92, p = 0.001) compared to those in low chaos households. In most chaos categories, having a bed-time ritual was related to more child sleep, and mothers who viewed routines as "less/not important" reported more preschooler screen-time compared to mothers who viewed routines as "very important".

CONCLUSION

Promoting bed-time rituals and prioritizing routines, even somewhat, may be related to an improved balance of child movement behaviors. Innovative measures are needed to support families during periods of disruption such as that experienced in the COVID-19 pandemic.

Engineering a mobile platform to promote sleep in the pediatric primary care setting

Study Objectives

Pediatricians lack tools to support families at home for the promotion of childhood sleep. We are using the Multiphase Optimization Strategy (MOST) framework to guide the development of a mobile health platform for childhood sleep promotion. The objective of this study is to demonstrate feasibility of a mobile health platform towards treating children with insufficient sleep.

Methods

Children aged 10–12 years were enrolled (Study #1: N = 30; Study #2: N = 43). Participants wore a sleep tracker to measure sleep duration. Data were retrieved by a mobile health platform, programmed to send introductory messages during run-in (2 weeks) and goal achievement messages during intervention (7 weeks) periods. In study #1, participants were randomized to control, gain-framed incentive or loss-framed incentive arms. In study #2, participants were randomized to control, loss-framed incentive, normative feedback or loss-framed incentive plus normative feedback arms.

Results

In study #1, 1514 nights of data were captured (69%) and sleep duration during the intervention was higher by an average of 21 (95% CI: −8, 51) and 34 (95% CI: 7, 61) minutes per night for the gain-framed and loss-framed arms, respectively, compared to controls. In study #2, 2,689 nights of data were captured (81%), with no major differences in average sleep duration between the control and the loss-framed or normative feedback arms.

Conclusions

We have developed and deployed a mobile health platform that can capture sleep data and remotely communicate with families. Promising candidate intervention components will be further investigated under the optimization phase of the MOST framework.

Clinical Trials

Both studies included in this manuscript were registered at clinicaltrials.gov:

-Study #1: NCT03263338

-Study #2: NCT03426644

A Model of Adolescent Sleep Health and Risk for Type 2 Diabetes

PURPOSE OF REVIEW

This paper presents a review of the current literature in support of a model explaining the relationships between sleep health and risk for type 2 diabetes in adolescents.

RECENT FINDINGS

Short sleep duration is associated with risk of developing obesity in youth. Sleep restriction increases energy expenditure, but also increases hunger, appetite, and food intake, causing positive energy balance, impacting appetite-regulating hormones, and leading to increased eating late at night. Insufficient sleep may lead to reduced physical activity and greater sedentary behaviors. In addition, short sleep duration is associated with reduced insulin sensitivity. The cumulative negative consequences of insufficient sleep increase risk for type 2 diabetes. Applications to clinical care, public policy, and future research are discussed. Insufficient sleep in adolescence increases risk for type 2 diabetes directly through impact on insulin sensitivity and indirectly through increased dietary intake, sedentary activity, and weight gain.

Engineering a Mobile Platform to Promote Sleep in the Pediatric Primary Care Setting

Background

Pediatricians lack tools to support families at home for the promotion of childhood sleep. We are using the Multiphase Optimization Strategy (MOST) framework to guide the development of a mobile health platform for childhood sleep promotion.

Purpose

Under the preparation phase of the MOST framework, to demonstrate feasibility of a mobile health platform towards treating children with insufficient sleep.

Methods

Children aged 10-12y were enrolled (Study #1: N=30; Study #2: N=43). Participants wore a sleep tracker to measure sleep duration. Data were retrieved by a mobile health platform, programmed to send introductory messages during run-in (2 weeks) and goal achievement messages during intervention (7 weeks) periods. In study #1, participants were randomized to control, gain-framed incentive or loss-framed incentive arms. In study #2, participants were randomized to control, loss-framed incentive, normative feedback or loss-framed incentive plus normative feedback arms.

Results

In study #1, 1,514 nights of data were captured (69%) and sleep duration during the intervention was higher by an average of 21 (95% CI: -8, 51) and 34 (95% CI: 7, 61) minutes per night for the gain-framed and loss-framed arms, respectively, compared to controls. In study #2, 2,689 nights of data were captured (81%), with no major differences in average sleep duration between the control and the loss-framed or normative feedback arms.

Conclusion

We have developed and deployed a mobile health platform that can capture sleep data and remotely communicate with families. Promising candidate intervention components will be further investigated under the optimization phase of the MOST framework.