In the absence of a submission from the holder of the marketing authorisation, metformin hydrochloride (Glucophage SR®) cannot be endorsed for use within NHS Wales for the reduction in the risk or delay of the onset of type 2 diabetes mellitus in adult, overweight patients with IGT and/or IFG, and/or increased HbA1C who are: at high risk for developing overt type 2 diabetes mellitus and; still progressing towards type 2 diabetes mellitus despite implementation of intensive lifestyle change for 3 to 6 months. Treatment with Glucophage SR® must be based on a risk score incorporating appropriate measures of glycaemic control and including evidence of high cardiovascular risk. Lifestyle modifications should be continued when metformin is initiated, unless the patient is unable to do so because of medical reasons.