Diabetes-specific family functioning typology associated with intervention engagement and effects: secondary analyses from a randomized controlled trial

Observationally, family and social support are important for optimal diabetes self-management; however, interventions targeting family/social support have not consistently been effective. A novel, diabetes-specific family functioning typology offers the opportunity to classify types of baseline family functioning to determine for whom family interventions may be effective. We examined the effects of an intervention by baseline type of family functioning post hoc, to inform differential benefit from interventions. Participants were randomized to enhanced treatment as usual or a 9-month, mobile phone-delivered, family-focused, self-care support intervention. Adults with type 2 diabetes (N = 318) who participated in the randomized clinical trial (RCT) and provided baseline data were included. We determined participants' diabetes-specific family functioning types at baseline using a validated, survey-administered, typology assessment tool. We investigated the associations between type and engagement (eg, attending coaching sessions and responding to text messages) and psychosocial (eg, well-being and diabetes distress) and glycemic outcomes at mid- and post-treatment. Despite overall high engagement, there was variability across types in engagement and effects. WantMoreInvolvement benefited the most; Satisfied withLowInvolvement showed early improvements that waned; Collaborative &Helpful were highly engaged but derived minimal benefits from the intervention; and CriticallyInvolved benefitted the least and may have experienced some harm. We demonstrated the utility of a novel diabetes-specific family functioning typology to explain variability in response to a family-focused intervention. Findings from this work answer the calls for systems-level consideration in precision behavioral medicine and drive hypothesis generation for future, tailored interventions. The larger RCT is registered with ClinicalTrials.gov (NCT04347291).