PROJECT SUMMARY The vast majority of adults with Acute Respiratory Failure (ARF) in the U.S. now survive hospitalization as a result of clinical advances. Many ARF survivors experience new and persistent physical, cognitive, and mental health impairments and >50% of survivors remain dependent on caregiver assistance 1 year after discharge. Family/caregivers (“care partners”) of ARF patients also experience mental health symptoms and financial stress, and have difficulty reconciling their expectations with ARF survivors’ recovery. A 2015 systematic review found persistent symptoms of depression in 23% - 29% of family caregivers of ICU survivors 1 year after discharge. This is comparable to rates of depression in caregivers for people with dementia and significantly higher than the prevalence of depression in the U.S. adult population. A 2020 systematic review of 11 RCTs testing interventions to mitigate family emotional distress following critical illness reported that all trials had failed, suggesting a need for innovative approaches. We posit that expectations within ARF survivor- care partner dyads influence behaviors and outcomes and are a malleable and innovative target for dyadic coping interventions (DCI). However, before DCI can be developed, essential research is required to understand how expectations about recovery are formed following ARF and how they impact the mental health and coping behaviors of ARF survivor-care partner dyads. We hypothesize that when ARF survivor-care partner dyads lack confidence in their shared ability to manage new care needs (i.e. low self-efficacy) expectations for recovery within a dyad influence both mental health and dyadic coping. The overarching objectives of this application are to learn how expectations about ARF survivorship are related to dyadic mental health symptoms and dyadic coping (Aims 1 & 2) and to understand how expectations about ARF recovery are formed and shaped over time within survivor-care partner dyads (Aim 3). To achieve the above objectives, we propose a mixed methods research program. First, we will conduct a longitudinal cohort study of 235 dyads of adult ARF survivors and care partners from 4 hospitals (Aims 1 & 2). Thereafter in Aim 3, we will conduct semi- structured interviews with ≥36 Aim 1 dyads divided across a maximum variation sample of dyads whose expectations for recovery: a) improved, b) worsened, c) differed substantially between dyad members. We will also explore how dyads approach dyadic coping and health management to identify gaps that are potentially modifiable with intervention. The proposed work will provide essential information for developing dyadic coping interventions specifically tailored to the challenges of ARF survivorship.