Virtual Reality Relaxation for Insomnia

The Pre-Sleep Arousal Scale (PSAS) is a 16-item questionnaire that assesses symptoms of cognitive (e.g., racing thoughts, worry about not falling asleep) and somatic arousal (e.g., muscle tension, rapid heartbeat) experienced at bedtime. Participants rate the intensity of each symptom as they attempt to fall asleep using a five-point Likert scale ranging from 1 (not at all) to 5 (extremely). Higher scores on the scale indicate elevated levels of pre-sleep arousal.

The Insomnia Severity Index (ISI) is a self-administered questionnaire used to assess the severity of insomnia. The ISI consists of seven items that evaluate the nature, intensity, and consequences of insomnia over the past month. The dimensions assessed include difficulties initiating or maintaining sleep (sleep onset latency, nighttime awakenings, early morning awakenings), dissatisfaction with sleep, the impact of sleep difficulties on daytime functioning, and the level of distress caused by these problems. Each item is rated on a 5-point Likert scale from 0 (not at all) to 4 (extremely), yielding a total score ranging from 0 to 28. Interpretation thresholds are as follows: 0-7 (no clinically significant insomnia), 8-14 (subthreshold insomnia), 15-21 (moderate insomnia), and 22-28 (severe insomnia).

The Beck Anxiety Inventory (BAI) will be used to assess participants' anxiety symptoms. The BAI consists of 21 items rated on a Likert scale from 0 (Not at all) to 3 (Severely - It bothered me a lot). The total score is calculated by summing the responses to all 21 items (0-7 points are considered to reflect a minimal level of anxiety; scores of 8-15 indicate mild anxiety; scores of 16-25 reflect moderate anxiety; and scores of 26-63 indicate severe anxiety).

The Beck Depression Inventory - Second Edition (BDI-II) is a self-administered questionnaire designed to assess the severity of depressive symptoms. It consists of 21 items corresponding to various depressive symptoms, each rated on a four-point Likert scale from 0 (least severe) to 3 (most severe). The total score ranges from 0 to 63, with higher scores indicating greater severity of depressive symptoms.

The Ru-SATED scale is a self-report questionnaire that assesses six dimensions of sleep health. It evaluates regularity (i.e., going to bed and waking up at about the same time each day), satisfaction with sleep, alertness (i.e., the ability to stay awake without dozing off during the day), timing (i.e., typically being in bed between 2:00 and 4:00 a.m.), efficiency (i.e., spending less than 30 minutes awake per night), and sleep duration (i.e., sleeping between 7 and 9 hours per night). Each dimension is rated on a five-point Likert scale from 0 (never) to 4 (always). The total score, obtained by summing the scores across the six dimensions, ranges from 0 to 24, with higher scores indicating better sleep health.

The Positive and Negative Affect Schedule (PANAS) is a self-report questionnaire used to assess the intensity of affective states. The instrument consists of 20 adjectives, with 10 describing positive affect and 10 describing negative affect. Participants rate, on a five-point Likert scale ranging from 1 (very slightly or not at all) to 5 (extremely), the extent to which they experience each emotion. A high score on the positive affect subscale reflects a state of high energy and pleasurable emotions, while a high score on the negative affect subscale indicates subjective distress involving multiple negative emotions.

Participants will record sleep diaries each day duration the 4-week of intervention. Participants will complete 14-day sleep diaries at baseline before recruitment, end of intervention and 12 weeks after end of intervention. The following parameters extracted from the diary will be used for analysis: sleep latency (the time in minutes required to transition from wakefulness to sleep), number of awakenings (the count of nocturnal awakenings lasting more than 5 minutes), wake after sleep onset (the total time in minutes spent awake after initially falling asleep and before final awakening), and sleep efficiency (the proportion of total sleep time relative to time spent in bed).

A portable sleep monitor (Prodigy 2 Sleep Monitor) will be used to collect objective measures of sleep quality. The following parameters recorded from the sleep monitor will be used for analysis: sleep latency (the time in minutes required to transition from wakefulness to sleep), number of awakenings (the count of nocturnal awakenings lasting more than 5 minutes), wake after sleep onset (the total time in minutes spent awake after initially falling asleep and before final awakening), and sleep efficiency (the proportion of total sleep time relative to time spent in bed).

Participants will complete a brief acceptability questionnaire based on the Theoretical Framework of Acceptability (TFA). The questionnaire includes eight items assessing the following constructs: affective attitude, perceived burden, ethicality, perceived effectiveness, intervention coherence, self-efficacy, opportunity costs, and overall acceptability. All items are rated on a 5-point Likert scale ranging from 1 to 5, with response anchors varying by item (e.g., strongly disagree to strongly agree, or not at all appreciated to strongly appreciated). Higher scores indicate greater acceptability, except for items assessing perceived burden and opportunity costs, for which higher scores reflect greater burden or interference with other priorities.

Retention is defined as the proportion of participants who complete the 4-week intervention and all associated assessments, including Baseline (Day 1), end of intervention (Week 4), and 12 weeks after end of intervention (Week 16).

Intervention adherence is defined as the total number of intervention sessions completed over the 4-week intervention period.