Glycemic outcomes of a family-focused intervention for adults with type 2 diabetes: Main, mediated, and subgroup effects from the FAMS 2.0 RCT

Aims: Family/friend Activation to Motivate Self-care (FAMS) is a self-care support intervention delivered via mobile phones. We evaluated FAMS' effects on hemoglobin A1c (HbA1c) and intervention targets among adults with type 2 diabetes in a 15-month RCT.Methods: Persons with diabetes (PWDs) were randomized to FAMS or control with their support person (family/ friend, optional). FAMS included monthly phone coaching and text messages for PWDs, and text messages for support persons over a 9-month intervention period.Results: PWDs (N = 329) were 52 % male, 39 % reported minoritized race or ethnicity, with mean HbA1c 8.6 +/- 1.7 %. FAMS improved HbA1c among PWDs with a non-cohabitating support person (-0.64 %; 95 % CI [-1.22 %,-0.05 %]), but overall mean effects were not significant. FAMS improved intervention targets including self efficacy, dietary behavior, and family/friend involvement during the intervention period; these improvements mediated post-intervention HbA1c improvements (total indirect effect-0.27 %; 95 % CI [-0.49 %,-0.09 %]) and sustained HbA1c improvements at 12 months (total indirect effect-0.19 %; 95 % CI [-0.40 %,-0.01 %]). Conclusions: Despite improvements in most intervention targets, HbA1c improved only among PWDs engaging non-cohabitating support persons suggesting future family interventions should emphasize inclusion of these relationships. Future work should also seek to identify intervention targets that mediate improvements in HbA1c.