With a prevalence of about 10% chronic insomnia is a common problem. The standard treatment for insomnia is cognitive behavioral therapy. According to many, the core element within this treatment is sleep restriction. This element has been examined separately in a couple of studies and also appears to be effective in isolation. In the current study the aim is to get more information about the effectiveness of this core element of the treatment. For this reason, a randomized study is conducted to compare sleep restriction with a diary control condition. The second aim in this study is to determine mechanisms behind treatments. Network intervention analysis will be used to determine which specific symptoms are associated with therapy success. This is the reason that throughout the study weekly and daily measures will be conducted. The expectations are that: * Participants in the sleep restriction condition will improve more on insomnia complaints than the sleep diary control condition (primary outcome) * Participants in the sleep restriction condition will improve more on sleep diary outcomes and other secondary outcomes compared to the sleep diary control condition (secondary outcome)
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
148
Treatment consists of sleep restriction treatment for insomnia. In this treatment, participants limit their bedtimes to the time they actually sleep. If they sleep most of the time in bed again then bedtimes are slowly built up again. This treatment technique has already been studied in several trials and found to be effective. Mode of delivery is an online booklet, online exercises and weekly telephone support
As an active control condition people monitor their sleep with a sleep diary (also included in the sleep restriction intervention)
University of Amsterdam
Amsterdam, North Holland, Netherlands
Insomnia Severity Index
The Insomnia Severity Index is a seven item-scale scored on a five-point Likert scale (Bastien et al. 2001). The total score ranges from 0 to 28. Higher scores indicate more insomnia.
Time frame: Change from baseline to six weeks post-randomization
Sleep diary: sleep onset latency
Sleep onset latency is assessed with the Carney (2012) consensus sleep diary. This is measured in minutes (higher scores indicating longer sleep onset latency).
Time frame: Change from baseline to six-weeks post-randomization
Sleep diary: sleep onset latency
Sleep onset latency is assessed with the Carney (2012) consensus sleep diary. This is measured in minutes (higher scores indicating longer sleep onset latency).
Time frame: Change from baseline to six-month follow-up (intervention only)
Sleep diary: wake after sleep onset
Wake after sleep onset is assessed with the Carney (2012) consensus sleep diary. This is measured in minutes (higher scores indicating longer wake after sleep onset).
Time frame: Change from baseline to six-weeks post-randomization
Sleep diary: wake after sleep onset
Wake after sleep onset is assessed with the Carney (2012) consensus sleep diary. This is measured in minutes (higher scores indicating longer wake after sleep onset )
Time frame: Change from baseline to six-month follow-up (intervention only)
Sleep diary: terminal wakefulness
Terminal wakefulness is assessed with the Carney (2012) consensus sleep diary. This is measured in minutes (higher scores indicating longer terminal wakefulness).
Time frame: Change from baseline to six-weeks post-randomization
Sleep diary: terminal wakefulness
Terminal wakefulness is assessed with the Carney (2012) consensus sleep diary. This is measured in minutes (higher scores indicating longer terminal wakefulness).
Time frame: Change from baseline to six-month follow-up (intervention only)
Sleep diary: sleep efficiency
Sleep efficiency is assessed with the Carney (2012) consensus sleep diary. This is measured in percentage (higher scores indicating better sleep efficiency).
Time frame: Change from baseline to six-weeks post-randomization
Sleep diary: sleep efficiency
Sleep efficiency is assessed with the Carney (2012) consensus sleep diary. This is measured in percentage (higher scores indicating better sleep efficiency).
Time frame: Change from baseline to six-month follow-up (intervention only)
Sleep diary: total sleep time
Total sleep time is assessed with the Carney (2012) consensus sleep diary. This is measured in minutes (higher scores indicating longer total sleep time).
Time frame: Change from baseline to six-weeks post-randomization
Sleep diary: total sleep time
Total sleep time is assessed with the Carney (2012) consensus sleep diary. This is measured in minutes (higher scores indicating longer total sleep time).
Time frame: Change from baseline to six-month follow-up (intervention only)
Sleep diary: time in bed
Time in bed is assessed with the Carney (2012) consensus sleep diary. This is measured in minutes (higher scores indicating longer time in bed).
Time frame: Change from baseline to six-weeks post-randomization
Sleep diary: time in bed
Time in bed is assessed with the Carney (2012) consensus sleep diary. This is measured in minutes (higher scores indicating longer time in bed).
Time frame: Change from baseline to six-month follow-up (intervention only)
Cognitive arousal
cognitive arousal is measured daily with a visual analogue scale
Time frame: Change from baseline to six weeks post randomization
Somatic arousal
Somatic arousal is measured daily with a visual analogue scale
Time frame: Change from baseline to six weeks post randomization
Current sleepiness
Sleepiness is measured daily with a visual analogue scale
Time frame: Change from baseline to six weeks post randomization
Insomnia Severity
The Insomnia Severity Index is a seven item-scale scored on a five-point Likert scale (Bastien et al. 2001). The total score ranges from 0 to 28. Higher scores indicate more insomnia.
Time frame: Change from baseline to six-month follow-up (intervention only)
Sleep safety
Sleep safety behaviors are measured with the Dutch translation of the 32-item Sleep-Related Behaviors Questionnaire-SRBQ (Ree \& Harvey, 2004). The total score ranges from 0 (no safety behaviors) to 128 (severe safety behaviors).
Time frame: Change from baseline to six weeks post-randomization
Sleep safety
Sleep safety behaviors are measured with the Dutch translation of the 32-item Sleep-Related Behaviors Questionnaire-SRBQ (Ree \& Harvey, 2004). The total score ranges from 0 (no safety behaviors) to 128 (severe safety behaviors).
Time frame: Change from baseline to six-month follow-up (intervention only)
Epworth Sleepiness Scale
To assess daytime sleepiness the Epworth Sleepiness Scale (ESS) is used. The ESS consists of 8-items on a 4-point Likert scale (range 0-24) with higher scores indicating more sleepiness.
Time frame: Change from baseline to six weeks post-randomization
Epworth Sleepiness Scale
To assess daytime sleepiness the Epworth Sleepiness Scale (ESS) is used. The ESS consists of 8-items on a 4-point Likert scale (range 0-24) with higher scores indicating more sleepiness.
Time frame: Change from baseline to six-month follow-up (intervention only)
Pre-sleep arousal
Sleep-related arousal was measured with the Pre-sleep Arousal Scale (PSAS) (Nicassio et al. 1985). The PSAS consists of 16 items that range from 1 ('not at all') to 5 ('extremely'), higher scores indicating more arousal (range 16-80).
Time frame: Change from baseline to six weeks post-randomization
Pre-sleep arousal
Sleep-related arousal was measured with the Pre-sleep Arousal Scale (PSAS) (Nicassio et al. 1985). The PSAS consists of 16 items that range from 1 ('not at all') to 5 ('extremely'), higher scores indicating more arousal (range 16-80).
Time frame: Change from baseline to six-month follow-up (intervention only)
Sleep-bed association
Sleep-bed association is measured with a newly constructed scale of 5 items on a 7-point Likert scale (0-6). Higher scores indicating a stronger sleep-bed association (range 0-30)
Time frame: Change from baseline to six weeks post-randomization
Sleep-bed association
Sleep-bed association is measured with a newly constructed scale of 5 items on a 7-point Likert scale (0-6). Higher scores indicating a stronger sleep-bed association (range 0-30)
Time frame: Change from baseline to six-month follow-up (intervention only)
Dysfunctional beliefs
Dysfunctional beliefs about sleep are measured using the 16-item Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS-16) (Morin et al. 2017). Items are scored on an 11-point Likert scale (0-10). Higher scores indicating more dysfunctional beliefs (range 0-160).
Time frame: Change from baseline to six weeks post-randomization
Dysfunctional beliefs
Dysfunctional beliefs about sleep are measured using the 16-item Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS-16) (Morin et al. 2017). Items are scored on an 11-point Likert scale (0-10). Higher scores indicating more dysfunctional beliefs (range 0-160).
Time frame: Change from baseline to six-month follow-up (intervention only)
Depression
Depression is measured with the Dutch version of a nine-item depression scale, the Patient Health Questionnaire-9 (PHQ-9; range 0-27, Cronbach's α = 0.94; Spitzer et al., 1999). Higher scores indicating more depression.
Time frame: Change from baseline to six weeks post-randomization
Depression
Depression is measured with the Dutch version of a nine-item depression scale, the Patient Health Questionnaire-9 (PHQ-9; range 0-27, Cronbach's α = 0.94; Spitzer et al., 1999). Higher scores indicating more depression.
Time frame: Change from baseline to six-month follow-up (intervention only)
Anxiety
Anxiety is measured with the Anxiety section of the Hospital Anxiety and Depression Scale (HADS-A; Cronbach's α = 0.84, seven items on a four-point Likert scale, scores ranging 0-21; Spinhoven et al., 1997). Higher scores indicating more anxiety.
Time frame: Change from baseline to six weeks post-randomization
Anxiety
Anxiety is measured with the Anxiety section of the Hospital Anxiety and Depression Scale (HADS-A; Cronbach's α = 0.84, seven items on a four-point Likert scale, scores ranging 0-21; Spinhoven et al., 1997). Higher scores indicating more anxiety.
Time frame: Change from baseline to six-month follow-up (intervention only)
Acceptance
Acceptance is measured with 10-items of the 'flexibiliteits index test'. Items are scored on a 7-point Likert scale (0-6) and higher scores indicate more acceptance (range 0-60).
Time frame: Change from baseline to six weeks post-randomization
Acceptance
Acceptance is measured with 10-items of the 'flexibiliteits index test'. Items are scored on a 7-point Likert scale (0-6) and higher scores indicate more acceptance (range 0-60).
Time frame: Change from baseline to six-month follow-up (intervention only)
Adverse events
Participants asked to report adverse events ("Did anything unpleasant happen to you that was related to your sleep or participation in the trial?"
Time frame: Six-weeks post-randomization
Treatment quality
Treatment quality is rated with a single question 'how do you rate the treatment'. This is rated on an 11-point Likert scale (0-10) with higher scores indicating more satisfaction (intervention only)
Time frame: Six-weeks post-randomization
Rating coach
Coaches are rated with a single question 'how satisfied were you with your coach during the treatment'. This is rated on an 11-point Likert scale (0-10) with higher scores indicating more satisfaction
Time frame: Six-weeks post-randomization
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