An Interactive School Sleep Behavior Modification Program
Phase: NA
Conditions: Sleep
Sponsor: Duke-NUS Graduate Medical School

Clinical Trial Registration 
 
 
Study Protocol and Data Analysis Plan 
 
 
Official Title:  A School-based Sleep Education Program 
 
 
Date: 24 July 2018 
 
 
NCT ID: not yet assigned 
 
 
 
 
 

 
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Study Protocol 
The present study aims to examine the effectiveness of a class-based interactive 
Sleep Education Program in improving sleep behavior of secondary school students. 
Participants will be randomly assigned to a Sleep Education Program or a Control 
Program. Participants in the Sleep Education Program will learn about the 
importance of sleep, what factors may prevent them from getting enough sleep, how 
they can manage their time to create more opportunity for sleep, and how they can 
overcome obstacles to time management. Participants in the Control Program will 
learn about various health-related topics, but will not learn about sleep. All 
participants will undergo four weekly class-based lessons, which use video 
presentations, in-class activities, discussions and take-home assignments to deliver 
the materials. Data will be collected on students' sleep habits, daytime functioning, 
mood, and time use at three time points: pre-program, immediately post-program 
and during a later follow-up. Sleep knowledge, habits, and attitudes towards sleep 
will be measured once during each time point using a sleep questionnaire. Sleep-
wake patterns will be measured in two ways: objectively using actigraphy, and 
subjectively using sleep diaries. At each time point, participants will wear the 
actiwatch for one week, and during this week they will also fill in a daily sleep diary. 
Additionally, during the same period of one week they will rate their subjective mood 
and subjective sleepiness daily, and time use will be measured using a time use 
diary app. For this, participants are asked to chronologically log their daily activities 
in the diary over the one-week period. Activities recorded will be analyzed in order to 
find out which activities take up most of the students’ time, and time spent on each 
activity will be correlated with data from various sleep variables, as collected by 
actigraphy and sleep diaries. Furthermore, time use data will be analyzed in order to 
asses if there are changes in the way students spend their time following the Sleep 
Education Program.  
 
Statistical Analysis Plan 
Primary outcome measures acquired in the current study are planned to be analyzed 
using SPSS Statistics (IBM) and MATLAB (MathWorks). Statistical analyzes that will 
be conducted include Analyses of Variance (ANOVAs), t-tests and correlations.  
 
Primary Outcome Measure 
1. Change in actigraphically measured sleep behavior between time 1 (pre-program), 
time 2 (post-program) and time 3 (follow-up), measured for one week in each of the 
three phases. 
 
Actigraphy will be used to objectively measure the following sleep behavior 
variables: bedtime, wake up time, time in bed, total sleep time, sleep efficiency, and 
number and duration of daytime naps. Data will be collected daily over the period of 
one week, at three time points (pre-program, post-program and follow-up). ANOVAs 
will be used to analyze changes in each variable between and within the two groups 
throughout the program. The independent variables are group, time point, and their 
interaction. Analyses will be performed on the average within each week of data 
collection, as well as between each individual time point (pre-program, post-program 
and follow-up). Post-hoc tests will be used to compare groups. 
 
 
 

 
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2. Change in sleep dairy reported sleep behavior between time 1 (pre-program), time 
2 (post-program) and time 3 (follow-up), recorded for one week in each of the three 
phases. 
 
Sleep diaries will be used to subjectively measure the following sleep behavior 
variables: bedtime, wake up time, total sleep time, sleep efficiency, and number and 
duration of nighttime awakenings and daytime naps. Data will be collected daily over 
the period of one week, at three time points (pre-program, post-program and follow-
up). ANOVAs will be used to analyze changes in each variable between and within 
the two groups throughout the program. The independent variables are group, time 
point, and their interaction. Analyses will be performed on the average within each 
week of data collection, as well as between each individual time point (pre-program, 
post-program and follow-up). Post-hoc tests will be used to compare groups. 
 
3. Change in the level of subjective mood between time 1 (pre-program), time 2 
(post-program) and time 3 (follow-up), measured once daily with a Mood Rating 
Scale over the period of one week. 
 
Score on the mood rating scale (1-9 points) will be measured. Data will be collected 
once daily over the period of one week, at three time points (pre-program, post-
program and follow-up). ANOVAs will be used to analyze changes in subjective 
mood between and within the two groups throughout the program. The independent 
variables are group, time point, and their interaction. Analyses will be performed on 
the average within each week of data collection, as well as between each individual 
time point (pre-program, post-program and follow-up). Post-hoc tests will be used to 
compare groups. 
 
4. Change in the level of subjective sleepiness between time 1 (pre-program), time 2 
(post-program) and time 3 (follow-up), measured once daily with the Karolinska 
Sleepiness Scale over the period of one week. 
 
Score on the Karolinska Sleepiness Scale (1-9 points) will be measured. Data will be 
collected once daily over the period of one week, at three time points (pre-program, 
post-program and follow-up). ANOVAs will be used to analyze changes in subjective 
sleepiness between and within the two groups throughout the program. The 
independent variables are group, time point, and their interaction. Analyses will be 
performed on data within each week of data collection, as well as between each 
individual time point (pre-program, post-program and follow-up). Post-hoc tests will 
be used to compare groups. 
 
5. Change in sleep knowledge, habits and attitudes between time 1 (pre-program), 
time 2 (post-program) and time 3 (follow-up), measured with a sleep questionnaire. 
 
Score on the sleep knowledge questionnaire will be measured (12 questions, true or 
false). Data will be collected once at three time points (pre-program, post-program 
and follow-up). ANOVAs will be used to analyze changes in score on the sleep 
questionnaire between and within the two groups throughout the program. The 
independent variables are group, time point, and their interaction. Analyses will be 
performed on the average within each week of data collection, as well as between 

 
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each individual time point (pre-program, post-program and follow-up). Post-hoc tests 
will be used to compare groups. 
 
6. Change in time use between time 1 (pre-program), time 2 (post-program) and time 
3 (follow-up), measured daily with a time use diary over the period of one week. 
 
Time use will be measured using a time use diary, in which activities are logged 
chronologically throughout the day. Data will be collected daily over the period of one 
week, at three time points (pre-program, post-program and follow-up). ANOVAs will 
be used to analyze changes in amount of time spent on different activities between 
and within the two groups throughout the program. The independent variables are 
group, time point, and their interaction. Analyses will be performed on the average 
within each week of data collection as well as separately for school days and free 
days, and also between each individual time point (pre-program, post-program and 
follow-up). Post-hoc tests will be used to compare changes between the two groups. 
 
7. Relationship between sleep and time use. 
 
Amount of time spent on each activity, measured by a time use diary, will be 
correlated with sleep variables, measured by actigraphy and a sleep diary, to identify 
types of activities that relate to short sleep. Data will be collected daily over the 
period of one week, at three time points (pre-program, post-program and follow-up). 
Pearson’s or Spearman’s correlations will be used to correlate scores on the 
different variables.