Well-being outcomes of a family-focused intervention for persons with type 2 diabetes and support persons: Main, mediated, and subgroup effects from the FAMS 2.0 RCT.

AIMS: Type 2 diabetes self-management occurs within social contexts. We sought to test the effects of Family/friend Activation to Motivate Self-care (FAMS), a self-care support intervention delivered via mobile phones, on psychosocial outcomes for persons with diabetes (PWDs) and their support persons. METHODS: PWDs had the option to enroll with a friend/family member as a support person in a 15-month RCT to evaluate FAMS versus enhanced usual care. FAMS included 9 months of monthly phone coaching and text message support for PWDs, and text message support for enrolled support persons. RESULTS: PWDs (N = 329) were 52% male and 39% reported minoritized race or ethnicity ; 50% enrolled with elevated diabetes distress. Support persons (N = 294) were 26% male and 33% reported minoritized race or ethnicity. FAMS improved PWDs' diabetes distress (d = -0.19) and global well-being (d = 0.21) during the intervention, with patterns of larger effects among minoritized groups. Post-intervention (9-month) and sustained (15-month) improvements were driven by changes in PWDs' self-efficacy, self-care behaviors, and autonomy support. Among support persons, FAMS improved helpful involvement without increasing burden or harmful involvement. CONCLUSIONS: FAMS improved PWDs' psychosocial well-being, with post-intervention and sustained improvements driven by improved self-efficacy, self-care, and autonomy support. Support persons increased helpful involvement without adverse effects.