Condition category
Not Applicable
Date applied
Date assigned
Last edited
Prospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
During adolescence the biological clock changes. This change means that teenagers find it difficult to fall asleep early in the evening, and difficult to get up in the morning. Pilot work in the U.K. suggests that delaying the school start time until 10am improves performance in GCSE grades. This is likely to be due to the teaching is happening when teenagers are biologically more alert and able to engage in learning. As well as biological changes, teenagers face a lot of social pressures. Using electronic devices late into the evening may impact on sleep. This is also a time when teenagers are facing the stress of examinations and the pressure to perform well. Alongside the delayed school start time we will also be delivering a sleep education package, to teach teenagers how to get good sleep, and maintain it during periods of stress. There is strong evidence that sleep quality impacts on learning. The aims of this study are to investigate the impact, primarily on pupils’ GCSE grades, of improving sleep through sleep education and introducing a later school day for GCSE students. We are also interested in how these interventions affect sleep, mood and well-being.

Who can participate?
Year 10 and year 11 students attending a state school in England.

What does the study involve?
Participating schools are randomly allocated to one of four groups. The students attending the schools in group 1 start their lessons later in the day, with the school day being from 10am to 4pm. The students attending the schools in group 2 are given sleep education classes, which will teach them about sleep, how to get good night’s sleep and how to get a good night’s sleep when feeling stressed. These sessions take place over a period of 5 weeks and are from one hour a week. Those students in schools in group 3 start their school day at 10am and have the sleep education lessons. Those students attending schools in group 4 are used as controls and do not receive either intervention. The performance of the interventions are measured according to GCSE performance, sleep quality, day time sleepiness and general well-being experienced by all students taking part.

What are the possible benefits and risks of participating?
All schools involved in the study will be offered the sleep education package at the end, which will involve training teachers to deliver this engaging topic. There are no risks to taking part.

Where is the study run from?
The study is run from the University of Oxford and evaluated by the University of York and the University of Durham, but schools anywhere in England can participate.

When is the study starting and how long is it expected to run for?
February 2015 to September 2018

Who is funding the study?
1. The Wellcome Trust (UK) (grant code: 105428)
2. The Education Endowment Fund (UK)

Who is the main contact?
Dr Christopher-James Harvey

Trial website

Contact information



Primary contact

Dr Christopher-James Harvey


Contact details

Level 6
West Wing
John Radcliffe Hospital
United Kingdom
+44 (0)1865 234 957



Additional contact

Dr David Torgerson


Contact details

Director of York Trials Unit
Area 4
Seebohm Rowntree Building
Dept of Health Sciences
University of York
YO10 5DD
United Kingdom



Additional contact

Dr Carole Torgerson


Contact details

Durham University
School of Education
Leazes Road
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Comparing the effect of a delayed school start time, sleep education, both and teaching-as-usual on examination performance in 14 to 16 year olds: a factorial cluster randomised controlled trial


Study hypothesis

There are 3 primary hypotheses:
1. Delaying the school start time will lead to an improvement in GCSE performance, relative to sleep education and no intervention
2. Sleep education will lead to an improvement in GCSE performance relative to no intervention
3. A delayed start-time and sleep education will lead to greater improvement in GCSE performance relative to individual interventions or no intervention

The secondary hypothesis are:
1. Sleep education will lead to an improvement in sleep knowledge, better sleep, mood and well-being compared to baseline
2. A delay in the school start time will lead to a decrease in sleepiness and an improvement in mood and well being compared to baseline
3. Combined interventions will lead to an improvement in sleepiness, sleep, mood and wellbeing compared to baseline
4. Improvements in sleep will mediate improvements in GCSE performance

Ethics approval

Oxford central ethical committee., 16/04/2015, ref: MS-IDREC-C1-2015-076

Study design

This is an interventional study with a two by two factorial pragmatic field design.

Primary study design


Secondary study design

Cluster randomised trial

Trial setting


Trial type


Patient information sheet

Not available in web format. Please use contact details to request participant information sheets


Academic performance in year 10 and 11 pupils.


There are 3 intervention arms:
1. One arm will receive a delay in the school start day, starting at 1000 and finishing at 1600. This will be implemented in the academic year 2016/17.
2. One arm will receive sleep education, which will teach about sleep, how get good sleep and how to maintain sleep during periods of stress. Teachers will be trained in delivering this curriculum. It will be delivered over 5 weeks, 1 hour per week. This will be delivered to year 10 and 11 pupils in academic year 2015/16 and to year 10 in academic year 2016/17.
3. One arm will receive both interventions.

There is also a control arm. Schools in the control arm will receive no intervention.

Intervention type



Drug names

Primary outcome measures

GCSE scores

Secondary outcome measures

Secondary measures will look at sleep quality, sleepiness, chronotype and general well-being. This data will be gathered via survey comprising 4 questionnaires.

1. Sleep quality will be measured using the Sleep Condition Indicator (SCI)
2. Daytime sleepiness will be measured using the Cleveland Adolescent Sleepiness Questionnaire
3. Chronotype will be measured using the Munich Chronotype Questionnaire (MCTQ)
4. Well-being will be measured using Kidscreen-27

Ideally these will be delivered online, but paper versions will be available. These questionnaires will be administered twice in the first year of the study (once in January 2016 and again in June 2016) and 3 times in the following years in September, April and June. At the end of each academic year we will be asking schools to provide data on attendance, reason for non-attendance, disruptive behaviour/ exclusions and number of pupils requiring additional support.

The following will be collected from a sub-sample of pupils (20 pupils from each school) via bracelet sleep monitors:
1. Heart-rate
2. Temperature
3. Sleep-wake patterns

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

Secondary schools across England will be eligible to take part in the study if they agree to all of the study requirements.

Participant type


Age group




Target number of participants

100 schools in total, 25 in each cluster.

Participant exclusion criteria

In the sub-sample of 20 pupils in each school, pupils will be excluded is they report a sleep disorder, any other psychological disorder, physiological disorders which may interfere with sleep, heart-rhythm abnormalities, excessive caffeine consumption or use of drugs know to affect sleep or the central nervous system.

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

University of Oxford
United Kingdom

Trial participating centre

University of York
YO10 5DD
United Kingdom

Trial participating centre

University of Durham
United Kingdom

Sponsor information


University of York

Sponsor details

Exhibition Square
United Kingdom

Sponsor type




University of Oxford

Sponsor details

Research Services
University Offices
Wellington Square
United Kingdom
+44 01865 616575

Sponsor type




Funder type


Funder name

Wellcome Trust (grant code: 105428)

Alternative name(s)

Funding Body Type

private sector organisation

Funding Body Subtype



United Kingdom

Funder name

Education Endowment Fund (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

The evaluators will publish a report on the main outcome measures (academic outcomes) which will be available through the Education and Endowment Fund. The secondary measures and how these interact with the primary outcomes measures will be published in academic peer-reviewed journals, yet to be identified.

Intention to publish date

Participant level data

Not expected to be available

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes