REPAIR Sleep Study

Caregiver-PLwD dyads randomized to this arm will receive REPAIR Sleep, a 5-week, 60-minute, videoconference-delivered Cognitive Behavioral Therapy for Insomnia (CBT-I) intervention. Sessions are delivered once weekly to both members of the dyad together. The intervention targets behavioral and cognitive factors that perpetuate insomnia and is tailored to the needs of caregivers and persons living with dementia.

Participants will:

• Attend five weekly 60-minute virtual sessions with a trained interventionist
• Review and complete sleep diaries and daily adherence checklists
• Wear a wrist actigraph (CentrePoint Insight Watch) for 2 weeks before and during the 5-week intervention
• Practice CBT-I components between sessions (e.g., stimulus control, sleep compression, relaxation, cognitive strategies, sleep hygiene)

REPAIR Sleep is a dyadic CBT-I program delivered via videoconferencing over 5 weekly sessions (60 minutes each). Core components include:

• Stimulus control: establishing consistent wake times and strengthening the bed-sleep association
• Sleep compression: gradually adjusting time in bed to improve sleep efficiency, using a milder form appropriate for older adults and PLwD
• Relaxation training: techniques to reduce physiological and cognitive arousal at bedtime; can be practiced individually or together
• Cognitive therapy: identifying and modifying unhelpful thoughts and beliefs about sleep and its consequences
• Sleep hygiene education: optimizing environmental and behavioral factors that influence sleep

The intervention uses written and recorded agreements and daily logs to support memory challenges in PLwD and to promote consistent practice of sleep behaviors. Both dyad members attend all sessions.

Caregiver-PLwD dyads randomized to this arm will receive Healthy Living, a 5-week, 60-minute, videoconference-delivered attention control intervention adapted from the National Institute on Aging's Go4Life program. The content focuses on general health and wellness (e.g., nutrition, physical activity, fall prevention), with sleep hygiene included as one topic. Sleep-specific behavioral and cognitive strategies from CBT-I are not provided in this arm.

Participants will:

• Attend five weekly 60-minute virtual sessions with a facilitator
• Receive a manual and workbook with educational materials and exercises
• Complete health-related journals (e.g., food intake, physical activity, sleep hygiene practices)
• Wear a wrist actigraph and complete sleep diaries on the same schedule as the intervention arm

Healthy Living is an attention-matched, 5-week behavioral health education program delivered via videoconferencing. Weekly 60-minute sessions cover:

• Week 1: Healthy aging principles, components of a healthy lifestyle, nutrition basics, budgeting for nutritious meals, meal planning, and food journaling
• Week 2: Sleep hygiene education, introduction to flexibility exercises and stretches, activity journaling, and goal setting
• Week 3: Balance exercises, fall prevention strategies (including safe bed exits at night), and weight-bearing aerobic exercise
• Week 4: Strength training using resistance bands and light weights
• Week 5: Integration of exercise, nutrition, and sleep hygiene; review and goal setting for continued healthy living The program emphasizes goal setting, progress tracking, and behavioral reinforcement, with dyads encouraged to implement lifestyle changes and discuss successes and challenges during sessions.

This will be reported as a change in total minutes scored as sleep per night. Data will be collected through actigraphy. Actigraphy provides continuous movement-based estimates of sleep-wake patterns.

Higher TST indicates better sleep.

This will be reported as a percentage of time in bed spent asleep Data will be collected through actigraphy. Actigraphy provides continuous movement-based estimates of sleep-wake patterns.

Higher (SE) indicates better sleep.

Change in quality of life measured using the World Health Organization Quality of Life - BREF (WHOQOL-BREF). This instrument assesses four domains:

• Physical Health
• Psychological
• Social Relationships
• Environment

Items are rated on a Likert scale and transformed to domain scores:

• Score Range: domain scores typically scaled 0-100
• Direction: higher scores indicate better quality of life Data will be reported as domain scores and, if desired, an overall summary, with change from baseline for each dyad member.

Change in depressive symptoms measured using the Center for Epidemiologic Studies Depression Scale (CES-D).

• Items: 20 self-report items
• Scale: each item rated 0-3 based on frequency of symptoms
• Score Range: 0-60
• Direction: higher scores indicate more severe depressive symptoms; scores ≥16 often indicate clinically relevant depressive symptoms in research contexts Data will be reported as total CES-D score and change from baseline for caregivers and PLwD.

Change in affect measured using the Positive and Negative Affect Schedule (PANAS). The PANAS includes two 10-item subscales:

• Positive Affect (PA): measures enthusiasm, alertness, and activity
• Negative Affect (NA): measures distress and unpleasurable engagement

Each item is rated on a Likert scale (e.g., 1-5), and subscale scores are summed:

• Score Range: typically 10-50 for each subscale
• Direction: higher PA = more positive affect; higher NA = more negative affect Data will be reported as PA and NA subscale scores and change from baseline for each dyad member.

Change in perceived stress measured using the Perceived Stress Scale (PSS). The PSS is a widely used self-report questionnaire assessing the degree to which situations in one's life are appraised as stressful over the past month.

• Scale: typically 10 items (PSS-10), each rated 0-4
• Score Range: 0-40
• Direction: higher scores indicate greater perceived stress Data will be reported as total PSS score at each time point and change from baseline for caregivers and PLwD separately.