We sought to examine the efficacy of motivational interviewing with teenagers aged 14-17 years with type 1 diabetes. In a randomized controlled trial analyzed by intention to treat, 66 teenagers with type 1 diabetes attending diabetes clinics in South Wales, U.K., were randomly assigned to the intervention group (38) and control group (28). Teenagers in the intervention group received motivational interviewing, and the control group received support visits. All participants received individual sessions over 12 months. The main outcome measures assessed at baseline, 6, 12, and 24 months were serum A1C and psychosocial self-report questionnaires including quality of life and well-being measures. At 12 months, 60 patients had complete data. At the end of the intervention (12 months), the mean A1C in the motivational interviewing group was significantly lower than in the control group (P = 0.04), after adjusting for baseline values. At 24 months (when n = 47), this difference in A1C was maintained (P = 0.003). There were differences in psychosocial variables at 12 months, with the motivational interviewing group indicating more positive well-being, improved quality of life, and differences in their personal models of illness (all P < 0.01). Some of these differences were maintained at 24 months. Motivational interviewing can be an effective method of facilitating behavioral changes in teenagers with type 1 diabetes with subsequent improvement in their glycemic control.
