The effects from delayed school start on adolescent sleep, health and school performances

A quasi-experimental evaluation of delayed school start on Swedish adolescents’ sleep, health, and school performances in comparison to usual school start times

Status

Recruiting

Phases

Unknown

Study type

Observational

Source

ISRCTN

Registry ID

ISRCTN60202879

Enrollment

5000

Registered

2017-08-10

Start date

2017-09-15

Completion date

Unknown

Last updated

2017-11-27

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Sleep duration, mental health, BMI, academic performance Not Applicable

Interventions

All upper secondary students in one Swedish municipality will be subject to delayed school start and be compared to themselves over time as well as students in three other municipalities. The study is

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: Adolescents (questionnaires and focus group interviews): 1. Upper secondary school student 2. Age: 16-19 3. Gender: all Teachers and school health staff (focus group interviews): 1. Teachers in upper secondary school 2. Any age 3. Gender: all

Exclusion criteria

Exclusion criteria: Does not meet inclusion criteria

Design outcomes

Primary

Measure	Time frame
1. Sleep habits and sleep duration, assessed using the School Sleep Habits Survey (SSHS) late in September 2017, 2018, 2019, early in December 2017, late in May 2018, 2019 2. Grades, assessed using official records and survey questions from the SSHS every semester in conjunction with standard measure times 3. Attendance, assessed using school records and survey questions from the SSHS every semester in conjunction with standard measure times 4. Daytime sleepiness, assessed using SSHS late in September 2017, 2018, 2019, early in December 2017, late in May 2018, 2019 5. BMI, measured using school healthcare records (measured by nurse as part of standard school health appointment) annually	—

Measure

Time frame

1. Sleep habits and sleep duration, assessed using the School Sleep Habits Survey (SSHS) late in September 2017, 2018, 2019, early in December 2017, late in May 2018, 2019 2. Grades, assessed using official records and survey questions from the SSHS every semester in conjunction with standard measure times 3. Attendance, assessed using school records and survey questions from the SSHS every semester in conjunction with standard measure times 4. Daytime sleepiness, assessed using SSHS late in September 2017, 2018, 2019, early in December 2017, late in May 2018, 2019 5. BMI, measured using school healthcare records (measured by nurse as part of standard school health appointment) annually

—

Secondary

Measure	Time frame
1. Insomnia symptomatology, assessed using the Insomnia Severity Index (ISI), Minimal Insomnia Sleep Symptoms questionnaire (MISS), sleep diary, late in September 2017, late in November 2017 (only 100 students). MISS will also be administered in late December 2017, late in September 2018 and 2019 as well as late in May 2018 and 2019 2. Mental health, assessed using the Center for Epidemiological Studies Depression Scale, Health Behaviours of School-aged Children Symptom Check-List (HBSC-SCL), Psychosomatic Problems Scale, questions on medication use and school stress from the HBSC, late in September 2017, 2018, 2019, early in December 2017, late in May 2018, 2019 3. Sociodemographic status (assessed using the Family Affluence Scale) and questions on physical activity and body perception, late in September 2017, 2018, 2019, early in December 2017, late in May 2018, 2019 4. Experiences from the implementation of delayed school start, assessed using focus group interviews (qualitative methodology) one month after delayed school start during the spring semester of 2018	—

Measure

Time frame

1. Insomnia symptomatology, assessed using the Insomnia Severity Index (ISI), Minimal Insomnia Sleep Symptoms questionnaire (MISS), sleep diary, late in September 2017, late in November 2017 (only 100 students). MISS will also be administered in late December 2017, late in September 2018 and 2019 as well as late in May 2018 and 2019 2. Mental health, assessed using the Center for Epidemiological Studies Depression Scale, Health Behaviours of School-aged Children Symptom Check-List (HBSC-SCL), Psychosomatic Problems Scale, questions on medication use and school stress from the HBSC, late in September 2017, 2018, 2019, early in December 2017, late in May 2018, 2019 3. Sociodemographic status (assessed using the Family Affluence Scale) and questions on physical activity and body perception, late in September 2017, 2018, 2019, early in December 2017, late in May 2018, 2019 4. Experiences from the implementation of delayed school start, assessed using focus group interviews (qualitative methodology) one month after delayed school start during the spring semester of 2018

—

Countries

Sweden

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026