Digital Sleep Therapy for Older Adults With Cognitive Impairment

Insomnia Severity Index (ISI) is a 7-item questionnaire used to examine overall insomnia severity. It consists of a five-point Likert type scale for each item (ranging from "no problem" = 0 to "severe problem" = 4) regarding symptoms over the past 2 weeks. Scores range from 0-28 with higher scores indicating greater insomnia symptom severity.

The British Columbia Cognitive Complaints Inventory (BC-CCI)12 is a 6-item tool to assess self-perceived cognitive decline. It probes any perceived problems associated with cognition, memory, expressive language, word finding, processing speed, and problem solving in reflection of the last 7 days. Answers for each question range from 0 (= "not at all") to 3 (= "Very much"). Scores are summed to a total out of 18 that reflects the cognitive complaint severity. The BC-CCI has a short reference period to ensure that it only reflects complaints outside of the treatment window.

The Pittsburgh Sleep Quality Index (PSQI) is a 19-item self-reported questionnaire which assesses sleep quality and disturbances over the previous 2 weeks so only variables across a time-period not including the therapy window are measured. Seven component scores are derived from the responses, each scored 0 (no difficulty) to 3 (severe difficulty). The component scores are summed to produce a global score (range 0-21) where a score of 5 or more indicates poor sleep quality.

The Geriatric Depression Scale (GDS) is a self-report measure of depression in older adults. Users respond in a "Yes/No" format. The shortened form comprises of 15 items chosen from the Geriatric Depression Scale-Long Form. These 15 items were chosen because of their high correlation with depressive symptoms in previous validation studies. Of the 15 items, 10 indicate the presence of depression when answered positively while the other 5 are indicative of depression when answered negatively. This form can be completed in approximately 5 to 7 minutes, making it ideal for people who are easily fatigued or are limited in their ability to concentrate for longer periods of time.

The General Anxiety Disorder-7 (GAD-7) is a 7-item self-administered scale used to assess the severity of generalised anxiety by asking how often participants have experienced symptoms in the previous two weeks. It consists of a three-point Likert type scale for each item (ranging from "not at all" = 0 to "nearly every day" = 3). All items are summed with total scores ranging from 0-21 where 5, 10 and 15 indicate the cut-off scores for mild, moderate and severe anxiety, respectively.

The Flinders Fatigue Scale (FFS) is a 7-item self-reported instrument designed to measure the level of subjective daytime fatigue experienced over the previous two weeks. 6-items consist of a 5-point Likert type scale ranging from "not at all" = 0 to "extremely" = 4. Item 5 uses a multiple-item checklist and is scored as a sum. All items are summed with total scores ranging from 0-31 with higher scores reflecting greater fatigue.

The Epworth Sleepiness Scale (ESS) is an 8-item self-reported questionnaire that provides a rating of general sleepiness in the last two weeks. Participants are asked to rate each item on a 4-point Likert scale from "would never dose" = 0 to "high chance of dozing" = 3. All items are summed with total scores ranging from 0-26 where scores >10 and >15 reflect above-average and pathological daytime sleepiness, respectively.

The EuroQol five-dimensional (EQ-5D) is a well-validated, generic instrument for measuring health related quality of life at the time of completion. The self-reported questionnaire is comprised of 2 components including: (1) Health state description - measured in terms of 5 dimensions of mobility, self-care, usual activities, pain/discomfort and anxiety/depression and (2) evaluation - where participants are asked to evaluate their overall health using a visual analogue scale. In Part 1, each item is assigned a level (ranging from "indicating no problem"1 - "indicating unable to/extreme problems" - 5) according to the response and this descriptive data is used to generate a health-related quality of life profile for the subject. Part II is scored from 0 (worst health state imaginable) to 100 (best health state imaginable).

The eHEALS Literacy Scale (eHEALS) will be used to assess digital health literacy. eHEALS is an 8-item, 5-point Likert-type questionnaire that measures a participant's perception of, and ability toward electronic health information27. Responses range from "strongly disagree" =1, to "strongly agree" = 5. Total scores are summed to range from 8 to 40 where lower scores indicate lower self-reported digital health literacy.