Impact of self monitoring of blood glucose in the management of patients with non-insulin treated diabetes: Open parallel group randomised trial

Objective: To determine whether self monitoring, alone or with instruction in incorporating the results into self care, is more effective than usual care in improving glycaemic control in non-insulin treated patients with type 2 diabetes. Design: Three arm, open, parallel group randomised trial. Setting: 48 general practices in Oxfordshire and South Yorkshire. Participants: 453 patients with non-insulin treated type 2 diabetes (mean age 65.7 years) for a median duration of three years and a mean haemoglobin A 1c level of 7.5%. Interventions: Standardised usual care with measurements of HbA 1c every three months as the control group (n=152); blood glucose self monitoring with advice for patients to contact their doctor for interpretation of results, in addition to usual care (n=150); and blood glucose self monitoring with additional training of patients in interpretation and application of the results to enhance motivation and maintain adherence to a healthy lifestyle (n=151). Main outcome measure HbA 1c level measured at 12 months. Results: At 12 months the differences in HbA 1c level between the three groups (adjusted for baseline HbA 1c level) were not statistically significant (P=0.12). The difference in unadjusted mean change in HbA 1c level from baseline to 12 months between the control and less intensive self monitoring groups was -0.14% (95% confidence interval -0.35% to 0.07%) and between the control and more intensive self monitoring groups was -0.17% (-0.37% to 0.03%). Conclusions: Evidence is not convincing of an effect of self monitoring blood glucose, with or without instruction in incorporating findings into self care, in improving glycaemic control compared with usual care in reasonably well controlled non-insulin treated patients with type 2 diabetes. Trial registration: Current Controlled Trials ISRCTN47464659.