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/friends 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) and their support persons (family/friend, optional) were randomized to FAMS or control. 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% from minoritized racial or ethnic groups, 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 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.