Efficacy of a Psychoeducational Intervention to Improve Sleep Health Among University Students

RU-SATED is the instrument used to measure sleep health. Sleep health varies according to individual, social and environmental conditions, and emphasises that good sleep is not simply the result of an absence of sleep disorders. In terms of its components, sleep health relates to (1) sleep duration, or the total number of hours of sleep obtained over 24 hours, (2) sleep efficiency, corresponding to the ease or otherwise with which an individual falls asleep and returns to sleep, and (3) timing, or how our sleep fits into a 24-hour day, (4) alertness, or sleepiness, which concerns a person's ability to maintain a state of attentive wakefulness throughout the day, (5) satisfaction, or subjectively represented sleep quality, and finally (6) sleep regularity.

More specifically, RU-SATED score is distributed between 0 and 12, with the higher the score, the better the person's sleep health.

Sleep satisfaction will be assessed using a single-item question from a sleep diary completed by participants each morning for seven consecutive days. The item reads: "How would you rate the quality of your sleep?" Responses are recorded on a 5-point Likert scale ranging from 1 ("very restless") to 5 ("Very deep"). Daily scores will be summed to obtain a total sleep satisfaction score ranging from 7 to 35. Higher scores indicate a higher perceived sleep quality. The measure provides a subjective evaluation of sleep quality from the participant's perspective.

Self-reported bedtime and wake-up time recorded daily in a sleep diary. Used to calculate the timing of sleep onset and wake time, as well as midpoint of sleep.

Calculated from self-reported sleep diary entries as the ratio of total sleep time to time in bed, expressed as a percentage.

Self-reported total sleep time calculated daily using sleep onset and wake-up time entries in the sleep diary.

Measured via self-reported bedtimes and wake-up times across multiple days using a sleep diary. Variability will be calculated using the standard deviation of sleep and wake times to assess sleep regularity.

This outcome is assessed students' beliefs about sleep hygiene using the Theory of Planned Behavior (TPB). Since no standardized tools exist, items were developed based on prior research and theoretical guidelines. Validity was confirmed through factor analysis and internal consistency testing.

The instrument includes 7-point Likert scales measuring:

Attitudes (6 items) - Perceptions of sleep hygiene. Higher scores indicate more favorable attitudes (score range of 6 to 42).

Subjective norms (4 items) - Perceived social expectations. Higher scores reflect stronger norms (score range of 4 to 28).

Motivation to comply (4 items) - Importance given to others' opinions (score range of 4 to 28).

Perceived control (4 items) - Confidence in maintaining good sleep habits (score range of 4 to 28).

Intention (3 items) - Readiness to adopt healthy sleep behaviors (score range of 3 to 21).

This structured approach ensures a comprehensive assessment of beliefs and behavioral influences.

Sleep hygiene is measured by the Sleep hygiene practice scale (SHPS), which is an instrument that measures sleep hygiene including 4 domains: (1) factors related to the sleep-wake cycle (e.g. irregular bedtime/rising time, lack of exposure to outside light), (2) factors related to activation and activating behaviours (e.g. falling asleep watching television or listening to music, intense exercise in the 2 hours before going to sleep), (3) factors related to consumption and diet (e.g.going to bed hungry, drinking alcohol close to bedtime), and (4) factors related to the sleep environment (e.g. sleeping environment too noisy, too bright, too hot). The total score is distributed between 30 and 180, where the higher the score, the higher the frequency of poor sleep hygiene practices.

This study evaluates self-efficacy in adopting, maintaining, and recovering sleep habits. Inspired by prior research, the instrument includes:

Adoption efficacy (2 items) - Confidence in changing sleep habits despite difficulties.

Maintenance efficacy (4 items) - Ability to sustain new sleep routines over time.

Recovery efficacy (3 items) - Capacity to resume habits after interruption. Each item is rated on a 4-point Likert scale (1 = "Completely false," 4 = "Completely true").

The range of scores is 2 to 8, 4 to 16 and 3 to 12 respectively. Higher scores indicate stronger self-efficacy in each domain.

Perceived stress is evaluated using the Perceived Stress Scale (PSS), which measures how stressful life situations are perceived. This self-administered questionnaire consists of 14 items, rated on a 5-point Likert scale (0 = "Never", 1 = "Almost never", 2 = "Sometimes", 3 = "Fairly often", 4 = "Very often"). The total score ranges from 0 to 56, with higher scores indicating greater perceived stress. The PSS will be used to control for stress levels during evaluation phases, especially around exam periods, when participants are expected to report higher stress levels.

Anxiety is evaluated using the GAD-7 (Generalized Anxiety Disorder scale). This 7-item self-report tool assesses anxiety symptoms experienced over the past two weeks, such as feeling nervous, unable to control worries, or having difficulty relaxing. Each item is scored from 0 to 3, indicating the frequency of symptoms. The total score ranges from 0 to 21, with thresholds at 5, 10, and 15 categorizing anxiety as mild, moderate, or severe. A score of 10 or higher is used to identify clinical levels of anxiety, which will be applied to distinguish students with clinically significant anxiety in this study.

The PHQ-9 will assess students' depression levels, with scores ≥10 indicating clinical depression. This self-administered questionnaire evaluates the presence and severity of depressive symptoms over the past two weeks. It consists of nine items rated on a four-point Likert scale (0 = "not at all" to 3 = "nearly every day"), resulting in a total score from 0 to 27. Severity thresholds are: minimal (1-4), mild (5-9), moderate (10-14), moderately severe (15-19), and severe (20-27).

The Insomnia Severity Index (ISI) assesses nocturnal and daytime insomnia symptoms. It consists of seven items rated on a five-point Likert scale, with total scores ranging from 0 to 28. Clinical thresholds categorize scores as no insomnia (0-7), subclinical insomnia (8-14), moderate clinical insomnia (15-21), and severe clinical insomnia (22-28). The ISI is a validated and reliable tool (Cronbach's alpha = .74). This measure will be used to control for sleep health outcomes, distinguishing students with scores above 10, indicating probable insomnia.