PROJECT SUMMARY Despite decades of research documenting the benefits of continuous positive airway pressure (CPAP) therapy, this highly effective treatment is not initiated, implemented, or persistently used by the millions of adults worldwide diagnosed with obstructive sleep apnea (OSA). An estimated 16% of patients refuse CPAP after a single night’s use, 29-83% do not adhere to current CPAP recommendations, and up to 50% abandon CPAP after one year. Untreated OSA is associated with a range of distressing symptoms, dangerous comorbid conditions, billions in healthcare spending, and higher all-cause mortality. Growing evidence shows that older adults, people with low socioeconomic status, and certain racial/ethnic minority groups are at higher risk for developing OSA, less likely to adhere to CPAP therapy, and experience worse outcomes than other groups. Other variables associated with CPAP non-adherence are commonly experienced CPAP side effects, knowledge deficits, low levels of self-efficacy, motivation, and confidence, and fragmented healthcare delivery. A variety of educational, supportive, behavioral, and mixed interventions have been tested in randomized controlled trials (RCTs). While each of these intervention types has demonstrated efficacy to varying degrees, key knowledge gaps remain as to: (1) which intervention type leads to the greatest improvements in long-term CPAP adherence and clinical outcomes; (2) who benefits most from a given intervention; and (3) what duration and/or sequence of interventions is required to effectively induce behavior change. Collectively, these gaps suggest the need for the development and testing of adaptive interventions aimed at improving CPAP adherence. Adaptive interventions capitalize on differences in how patients respond to intervention by providing appropriate modifications for those who need them and when they need them. To our knowledge, no fully powered RCTs have tested the effectiveness of adaptive interventions aimed at increasing CPAP adherence. Project objective: is to evaluate a telehealth-delivered adaptive intervention for persons newly diagnosed with OSA that promotes CPAP adherence and improves health outcomes and assess potential mediators and moderators of treatment response. Aim 1: Compare effects of motivational enhancement, device support, and standard care on primary and secondary outcomes at 3 mo. Aim 2: Determine which behavioral change treatment is most efficacious at promoting primary and secondary outcomes in participants who respond and do not respond to initial treatment at 6 and 12 mo. Aim 3. Assess if CPAP adherence is mediated by stage of change, self-efficacy, knowledge, and/or confidence and moderated by social economic status, race, and sex at 3 mo. By using an innovative adaptive design and telehealth-delivered approach, study results will directly lead to a more personalized approach to increasing long-term CPAP adherence and improving health outcomes of persons w...