The primary outcome will be the percentage of patients achieving adequate control of HbA1, blood pressure and cholesterol, comparing all participants in the intervention and control arms, whether or not those in the intervention arm attended ICC. The study is powered to detect a 10% difference in this outcome, and will include 51 practices and 5100 patients. We will also examine the effect of the intervention on process measures, such as the number of contacts in hospital and general practice. In the intervention arm we will document in detail the inputs provided by ICC, so that if successful the model can be adopted elsewhere.