Sleep and Blankets

Insomnia Severity Index (ISI) will be used to assess the severity of insomnia symptoms. The ISI is a brief self-report instrument consisting of seven items that evaluates the severity of sleep-onset, sleep maintenance, early morning awakening problems, satisfaction with current sleep pattern, interference with daily functioning, noticeability of impairment attributed to the sleep problem, and level of distress caused by the sleep problem. This corresponds in part to the diagnostic criteria of insomnia. Zero is the minimum value and equivalent to no insomnia and 28 is the maximum value and indicates clinical insomnia in severe degree.

The Pittsburg Sleep Quality Index (PSQI) will be used in order to measure subjective sleep quality. It consists of 19 self-rated items and has high internal consistency (Cronbach's α = 0.83) and test-retest reliability (r = 0.85). The minimum score is 0 and the maximum score is 21, with higher scores indicating poorer sleep quality.

ActTrust 1 (Condor Instruments, São Paulo, Brazil) will be used to measure rest/wake activity for 8 days at two timepoints in a subgroup (n=80). In addition to sleep/wake activity, ActTrust records information about amount and duration of ambient light and wrist temperature, allowing analyses of whether observed effects are related to group-differences in temperature. Extracted sleep variables include sleep onset latency (SOL), total sleep time (TST), sleep efficiency (SE), and wake after sleep onset (WASO). To help edit actigraphy data, participants will complete a sleep diary during this period, giving information about bedtime, time spent falling asleep, wake up time, rise time, estimated number of awakenings and self-rated sleep quality.

Diurnal salivary cortisol will be measured in a subgroup of participants (n = 80, 40 from each of groups 1 and 2) at two different time points. At each of these time points, participants will be instructed in home-based self-collection of 5 daily saliva samples for two consecutive days. The daily samples will be collected at personal waking (#1); 30 min. after waking (#2); 45 min. after waking (#3); between 4 and 6pm (#4); and at bedtime (#5). This sampling schedule allows for the assessment of both diurnal cortisol patterns and Cortisol Awakening Response (CAR) estimation. Samples will be collected in labelled Sarstedt salivettes and stored in sealable dark plastic bags to protect from sun exposure. Collection time will be written on the salivette by participants.

The Perceived Stress Scale (PSS) is a classic stress assessment instrument. Individual scores on the PSS can range from 0 to 40 with higher scores indicating higher perceived stress.

• Scores ranging from 0-13 would be considered low stress.
• Scores ranging from 14-26 would be considered moderate stress.
• Scores ranging from 27-40 would be considered high perceived stress.

The Patient Health Questionnaire-9 (PHQ-9) is a brief, self-administered tool used to screen for and assess the severity of depression in patients. It consists of nine questions about depressive symptoms experienced over the past two weeks, with answers scored on a 0-3 scale to determine the severity of depression. A total score is calculated, with higher scores indicating greater severity. The minimum score is 0 and the maximum score is 27.

The Generalised Anxiety Disorder Assessment (GAD-7) is a brief measure for symptoms of anxiety, based on the generalised anxiety disorder (GAD) diagnostic criteria described in the Diagnostic and Statistical Manual of Mental Disorders (DSM). A raw score (from 0 to 21) is presented as well as a percentile rank based on a normative community sample of age-related peers. Higher scores indicate higher levels of anxiety.

The Cognitive Failures Questionnaire (CFQ) measures how often people experience cognitive failures. Examples of cognitive failures include: forgetfulness, distractibility, and poor cognitive or behavioral performance that may be related to stress, mental health issues, physical health issues, or neurocognitive disorders (NOT due to ability). Respondents answer how often they experience the cognitive symptoms listed (e.g., "Do you find you forget your appointments?") on a scale from "Never" to "Very often". The CFQ contains 25 questions scored on a 5-point Likert scale from 0 ("Never") to 4 ("Very often"). A total score is obtained by summing the item responses and ranges from 0 to 100. Higher scores suggest higher frequency of cognitive failures.

The Epworth Sleepiness Scale (ESS) is a self-administered questionnaire with 8 questions. Respondents are asked to rate, on a 4-point scale (0-3), their usual chances of dozing off or falling asleep while engaged in eight different activities.

0-5 Lower Normal Daytime Sleepiness 6-10 Higher Normal Daytime Sleepiness 11-12 Mild Excessive Daytime Sleepiness 13-15 Moderate Excessive Daytime Sleepiness 16-24 Severe Excessive Daytime Sleepiness

The 36-Item Short Form Survey (SF-36) is an outcome measure instrument that is often used, well-researched, self-reported measure of health. SF-36 is a set of generic, coherent, and easily administered quality-of-life measures. Scores range from 0-100, with higher scores indicating better health (less pain, more function).

The WHO-5 is a self-report instrument measuring mental well-being. It consists of five statements relating to the past two weeks. Each statement is rated on a 6-point scale, with higher scores indicating better mental well-being.

The raw score is calculated by totaling the figures of the five answers. The raw score ranges from 0 to 25, 0 representing worst possible and 25 representing best possible quality of life. To obtain a percentage score ranging from 0 to 100, the raw score is multiplied by 4. A percentage score of 0 represents worst possible, whereas a score of 100 represents best possible quality of life.

Information on sociodemographic factors and comorbidity will be self-reported by all participants

Information about drugs, smoking, exercise, medical use, use of digital devices, nutrition etc.

The Pre-Sleep Arousal Scale (PSAS) is a validated and reliable self-report measure that will be used to assess evening pre-sleep arousal. It has been widely used in research as a reliable marker for cognitive and somatic arousal including in younger adults. On the Pre-Sleep Arousal Scale (PSAS), scores range from 16 to 80, with higher scores indicating greater pre-sleep arousal.

Circadian predispositions will be assessed using the 5-item self-rated reduced version of the Morningness-Eveningness Questionnaire (MEQr), which measures whether a person's peak alertness is in the morning or evening. The Morningness-Eveningness Questionnaire, Revised Short Form (rMEQ) is a shortened, five-item version of the original Horne and Östberg MEQ, developed to quickly assess an individual's chronotype (whether they are a morning or evening type) with good reliability and validity. The scores are summed, with a higher total score typically indicating morningness and a lower score indicating eveningness.

Scores typically range from 4 or 5 to 25 or 27, depending on the specific scoring methodology used. The sum total classifies individuals into categories:

Evening types (e.g., scores 4-10), Intermediate/Neither types (e.g., scores 11-18), Morning types (e.g., scores 19-25).

The Credibility/Expectancy Questionnaire will be used to assess treatment credibility and outcome expectancy. The measure was developed for clinical studies to measure treatment expectancy and rationale credibility. A minimum score of 6 and a maximum score of 54 for the total score, when all items are summed. Higher scores on both subscales and the total score reflect greater perceived treatment credibility and higher outcome expectancy.

Participants will also be asked to respond to questions about adherence and user experience of the assigned blanket in order to assess adherence, treatment satisfaction and potential barriers to use of weighted blankets. An extended version with open-ended questions about their experience with the blankets will be used during the follow-up assessment at the end of the open-trial period (T4).