Self monitoring of blood glucose costs the NHS more than £100m (€150m; $200m) each year and the cost is rising.1 For many people with insulin treated diabetes and their families, blood glucose self monitoring is an essential tool, enabling them to confirm hypoglycaemia or high glucose concentrations and to take corrective action. Yet large numbers of patients diligently record the results and then do nothing with them.

In this week's BMJ Farmer and colleagues report the results of a primary care trial in patients with well controlled type 2 diabetes who were not taking insulin. They found no evidence of an effect of blood glucose self monitoring on glycaemic control, with and without structured education, compared with usual care.2 This study confirms that the contribution of self monitoring is not clear in type 2 diabetes, particularly for those treated with diet alone or oral agents other than sulphonylureas. Furthermore, there is wide geographical variation in the use of self …