Shared Decision Making Between Patients and GPs in the Treatment of Type 2 Diabetes in Primary Care.

Background: Less than 20% of type 2 diabetes mellitus (T2DM) patients in different healthcare settings achieve all treatment goals to prevent cardiometabolic disease. A more personalised approach with shared decision making should increase that percentage. Because the ADDITION-Europe study demonstrated two (almost) equally effective treatments but with slightly different intensities, it may be a good starting point to discuss with the patients their diabetes treatment, taking into account both the intensity of treatment, clinical factors and patients' preferences. The aim of the study was to evaluate whether such an approach increases the proportion of treatment goals that T2DM patients achieve. Methods: In a cluster-randomised trial in 40 primary care practices that participated until 2009 in the ADDITION Study, 150 T2DM patients 60 - 80 years, known with T2DM for 8-15 years, will be included. Practices are randomised a second time, i.e. intervention practices in the ADDITION study could be control practices in the current study and vice versa. For the GPs from the intervention group a 2-hour training in shared decision making (SDM) was developed as well as a decision support tool to use during the consultation. These GPs plan the first visit with the patients to decide on the intensity of the treatment, personalised targets and the priorities of treatment. The control group will continue with the treatment they were allocated to in the ADDITION study (treatment-as-before). Follow-up: 24 months. The primary outcome is the proportion of patients who achieve all three treatment goals (HbA1c, blood pressure, total cholesterol) at 24 months. Secondary outcomes are the proportion of patients who achieve five treatment goals (HbA1c, blood pressure, total cholesterol , body weight, not smoking), evaluation of the SDM process (SDM-Q9), satisfaction with the treatment (DTSQ), wellbeing and quality of life (W-BQ12, ADD QoL-19), health status (SF-36, EQ-5D) and coping (DCMQ)