Prediction of adolescents' glycemic control 1 year after diabetes-specific family conflict: the mediating role of blood glucose monitoring adherence.

OBJECTIVE To test adherence to blood glucose monitoring (BGM) as a mediator between diabetes-specific family conflict and glycemic control (hemoglobin A(1c) [HbA(1c)] levels) for 1 year. DESIGN Three waves of prospective data spanning 1 year. SETTING Diabetes clinic in a large tertiary care children's hospital in the Midwestern United States. PARTICIPANTS One hundred forty-five dyads composed of an adolescent (aged 13-18 years) with type 1 diabetes mellitus and a parent. MAIN EXPOSURES Adolescent- and parent-rated diabetes-specific family conflict and mean daily BGM frequency obtained through meter downloads. MAIN OUTCOME MEASURE Levels of HbA(1c), abstracted from the medical record. RESULTS In separate general linear models, higher adolescent-rated family conflict scores at baseline predicted less frequent BGM at 6 months (β = -0.08 [P = .01]) and higher HbA(1c) levels at 12 months (β = 0.08 [P = .02]). In the multivariate model including baseline conflict and BGM as predictors of HbA(1c) levels, BGM was a significant predictor (β = -0.24 [P = .007]) and conflict was no longer significant (β = 0.05 [P = .11]), supporting the mediation hypothesis. Post hoc probing showed that BGM explained 24% of the variance in the conflict-HbA(1c) link. The mediation between parent-reported conflict and HbA(1c) levels via BGM adherence was partially supported (conflict predicting HbA(1c) in the zero-order equation, β = -0.24 [P = .004]; multivariate equation, β = 0.06 [P = .02]), and BGM frequency explained 16% of the conflict-HbA(1c) link. CONCLUSIONS Diabetes-specific family conflict in adolescence predicts deteriorations in BGM and subsequent glycemic control for at least 1 year. Results support ongoing intervention research designed to reduce family conflict and thus prevent a trajectory of declining adherence and glycemic control across adolescence.