Informed shared decision-making programme for patients with type 2 diabetes in primary care: cluster randomised controlled trial

OBJECTIVE: To translate an informed shared decision-making programme (ISDM-P) for patients with type 2 diabetes from a specialised diabetes centre to the primary care setting. DESIGN: Patient-blinded, two-arm multicentre, cluster randomised controlled trial of 6 months follow-up; concealed randomisation of practices after patient recruitment and acquisition of baseline data. SETTING: 22 general practices providing care according to the German Disease Management Programme (DMP) for type 2 diabetes. PARTICIPANTS: 279 of 363 eligible patients without myocardial infarction or stroke. INTERVENTIONS: The ISDM-P comprises a patient decision aid, a corresponding group teaching session provided by medical assistants and a structured patient–physician encounter. Control group received standard DMP care. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary endpoint was patient adherence to antihypertensive or statin drug therapy by comparing prescriptions and patient-reported uptake after 6 months. Secondary endpoints included informed choice, risk knowledge (score 0–11 from 11 questions) and prioritised treatment goals of patients and doctors. RESULTS: ISDM-P: 11 practices with 151 patients; standard care: 11 practices with 128 patients; attrition rate: 3.9%. There was no difference between groups regarding the primary endpoint. Mean drug adherence rates were high for both groups (80% for antihypertensive and 91% for statin treatment). More ISDM-P patients made informed choices regarding statin intake, 34% vs 3%, OR 16.6 (95% CI 4.4 to 63.0), blood pressure control, 39% vs 3%, OR 22.2 (95% CI 5.3 to 93.3) and glycated haemoglobin, 43% vs 3%, OR 26.0 (95% CI 6.5 to 104.8). ISDM-P patients achieved higher levels of risk knowledge, with a mean score of 6.96 vs 2.86, difference 4.06 (95% CI 2.96 to 5.17). In the ISDM-P group, agreement on prioritised treatment goals between patients and doctors was higher, with 88.5% vs 57%. CONCLUSIONS: The ISDM-P was successfully implemented in general practices. Adherence to medication was very high making improvements hardly detectable. TRIAL REGISTRATION NUMBER: ISRCTN77300204; Results.