Project Summary/Abstract Sleep disturbance is common in patients with cancer: 33% to 59% of patients (as opposed to 15% to 20% in the general population) report sleep disturbance, which is also documented in objective measures.1-4 Similarly, 36% to 95% of family caregivers of adult patients with cancer have self-reported or objectively assessed sleep disturbance.5,6 Chronic sleep disturbance is linked to various morbidities and mortality.3,7-11 Thus, sleep disturbance in adult patients with cancer and their caregivers is a substantial health problem requiring effective ways to improve it. Furthermore, evidence on the dyadic, cross-over effects of various cancer experiences of patients on their family caregivers’ health outcomes, and vice versa, is also accumulating.12-16 About 70% of adults sleep in the same bed with a significant other;17 so do adult cancer patients. Given sleep partners influence on each other’s sleep,18-20 intervening with both sleep partners, particularly among the adult patients with cancer and their caregivers who are at high risk for sleep disturbance, is a logical step. Our team developed a dyadic intervention, My Sleep Our Sleep (MSOS),21 to improve sleep quality of both adult patients with cancer and their caregivers who sleep in the same bed with the patient (hereafter sleep- partner caregivers). MSOS was developed including behavioral and cognitive components of the cognitive behavioral therapy tailored for insomnia (CBT-I), a gold standard for treating individuals with sleep disorders.22,23 MSOS, in four 1-hour weekly sessions that are delivered via HIPAA-compliant Zoom, is innovative as it accommodates the experiences of cancer and caring for a partner with cancer that are attributable to the sleep disturbance, targets both sleep partners, and capitalizes on the significant interpersonal nature of sleep. Our single arm pilot study provided preliminary support for the feasibility and acceptability of MSOS. This R21 application is to expand the investigation to test preliminary efficacy of MSOS against a brief individual-focused intervention (Brief Behavioral Treatment for Insomnia, BBTI 24-26) and to explore close relationship factors as the intervention’s success. The knowledge gained from this study will be used to refine the procedures, measurement, and session contents for a Phase III trial27,28 testing the efficacy of MSOS. Parameter estimates obtained from this R21, in addition to results from other studies, will help facilitating the development of R01 applications testing the MSOS intervention for diverse populations, comparing individual/actor and dyadic/partner effects between the two intervention conditions, with longer follow-ups to determine longer-term health effects. The knowledge from this project will also inform how to better Recognize, Assist, Include, Support, and Engage (RAISE) family caregivers in line with the RAISE Family Caregivers Act29 as well as may have substantial implications for tradit...