This study will first evaluate the feasibility of delivering the ENGAGE-TBI intervention in a community setting with adults with TBI.

Social isolation is a prevalent and highly prioritized concern among people with traumatic brain injury (TBI), contributing to poor physical and mental health outcomes. Existing rehabilitation interventions have focused primarily on remediating underlying impairments, with limited success in improving social participation. A patient-directed, self-management approach may offer a promising alternative. This study aims to evaluate the feasibility of ENGAGE-TBI, a novel, theory-driven occupational therapy intervention designed to reduce social isolation by increasing social participation among community-dwelling adults with TBI. Using a single-group pre-post design, this study will enroll 30 adults with TBI recruited through the Brain Injury Association of Missouri. ENGAGE-TBI is a 12-session group intervention co-facilitated by an occupational therapist and a peer mentor with TBI. The intervention integrates three core elements - social learning, guided problem-solving, and skilled community practice - delivered across six weeks. Feasibility outcomes include fidelity, participant engagement, satisfaction, attendance, and retention. The primary clinical outcome is social participation, measured using the PROMIS Ability to Participate in Social Roles and Activities. Feasibility outcomes will be examined descriptively against pre-specified benchmarks. Within-group Cohen's d effect sizes with 95% confidence intervals will be calculated to estimate intervention effects and variability, informing the design of a future randomized controlled trial. Findings will support the development of a fully-powered effectiveness trial. This study addresses a critical gap in TBI rehabilitation by testing a stakeholder-informed, community-based intervention that treats TBI as a chronic condition and prioritizes patient-directed goal achievement over impairment remediation.

Inclusion Criteria:

• at least 18 years old
• experienced a TBI > 6 months prior to enrollment, confirmed by a physician as documented in their medical record
• live in the St. Louis area
• report problems with social participation (retention of < 80% of pre-TBI social activities as measured by Activity Card Sort)

Exclusion Criteria:

• insufficient English language fluency to participate in the group intervention
• have active substance use disorder (PRIME-MD MINI)
• have an untreated psychotic disorder (PRIME-MD MINI)
• have severe memory impairment that would limit their ability to recall strategies with support (Montreal Cognitive Assessment, < 21)

This study will produce feasibility data and clinical outcome data on 30 participants with brain injury. De-identified data will be shared for all patient-reported outcome measures: Client Satisfaction Questionnaire-8, PROMIS Ability to Participate in Social Roles and Activities, PROMIS Social Isolation, and PROMIS-29. Raw data will be transformed to T-scores on the PROMIS measures, and T-scores will be used on the shared dataset.

Data will be made available six months after the end of the grant period and will be made available for a minimum of 10 years.

The dataset and data dictionary will be disseminated via the Washington University Research Data Repository, which is publicly available. Controlled access will not be used. The data that are shared will be shared by unrestricted download.