Abstract: We identified 16 randomised controlled trials with 3578 participants that fitted our inclusion criteria. These studies included a wide spectrum of interventions covering clinic-based brief interventions, Internet-based interventions that could be used from home and mobile phone-based interventions. The mean age of participants was between 46 to 67 years old and mean time since diagnosis was 6 to 13 years. The duration of the interventions varied between 1 to 12 months. There were three reported deaths out of 3578 participants. Computer-based diabetes self-management interventions currently have limited effectiveness. They appear to have small benefits on glycaemic control (pooled effect on glycosylated haemoglobin A1c (HbA1c): -2.3 mmol/mol or -0.2% (95% confidence interval (CI) -0.4 to -0.1; P = 0.009; 2637 participants; 11 trials). The effect size on HbA1c was larger in the mobile phone subgroup (subgroup analysis: mean difference in HbA1c -5.5 mmol/mol or -0.5% (95% CI -0.7 to -0.3); P < 0.00001; 280 participants; three trials). Current interventions do not show adequate evidence for improving depression, health-related quality of life or weight. Four (out of 10) interventions showed beneficial effects on lipid profile. One participant withdrew because of anxiety but there were no other documented adverse effects. Two studies provided limited cost-effectiveness data - with one study suggesting costs per patient of less than $140 (in 1997) or 105 EURO and another study showed no change in health behaviour and resource utilisation. Computer-based diabetes self-management interventions to manage type 2 diabetes appear to have a small beneficial effect on blood glucose control and the effect was larger in the mobile phone subgroup. There is no evidence to show benefits in other biological outcomes or any cognitive, behavioural or emotional outcomes.

Plain-language summary: We identified 16 trials involving 3578 adults that met our criteria. These studies included different types of interventions used in different places like touch screen computers in hospital clinics, computers connected to the Internet at home and programmes that communicated with mobile phones. The average age of people taking part was between 46 to 67 years old and most of those people had lived with diabetes for 6 to 13 years. Participants were given access to the interventions for 1 to 12 months, depending on the intervention. Three out of the 3578 participants died but these deaths did not appear to be linked to the trials. Overall, there is evidence that computer programmes have a small beneficial effect on blood sugar control - the estimated improvement in glycosylated haemoglobin A1c (HbA1c - a long-term measurement of metabolic control) was 2.3 mmol/mol or 0.2%. This was slightly higher when we looked at studies that used mobile phones to deliver their intervention - the estimated improvement in HbA1c was 5.5 mmol/mol or 0.5% in the studies that used mobile phones. Some of the programmes lowered cholesterol slightly. None of the programmes helped with weight loss or coping with depression. One participant withdrew because of anxiety but there were no obvious side effects and hypoglycaemic episodes were not reported in any of the studies. There was very little information about costs or value for money. In summary, existing computer programmes to help adults self-manage type 2 diabetes appear to have a small positive effect on blood sugar control and the mobile phone interventions appeared to have larger effects. There is no evidence to show that current programmes can help with weight loss, depression or improving health-related quality of life but they do appear to be safe.