Abstract: We included one randomised controlled trial involving 64 participants with schizophrenia or schizoaffective disorder. The average age of participants was 54 years; participants had been living with type 2 diabetes for on average nine years, and with their psychiatric diagnosis since they were on average 28 years of age. Investigators evaluated the 24-week Diabetes Awareness and Rehabilitation Training (DART) programme in comparison with usual care plus information (UCI). Follow-up after trial completion was six months. Risk of bias was mostly unclear but was high for selective reporting. Trial authors did not report on diabetes-related complications, all-cause mortality, adverse events, health-related quality of life nor socioeconomic effects. Twelve months of data on self care behaviours as measured by total energy expenditure showed a mean of 2148 kcal for DART and 1496 kcal for UCI (52 participants; very low-quality evidence), indicating no substantial improvement. The intervention did not have a substantial effect on glycosylated haemoglobin A1c (HbA1c) at 6 or 12 months of follow-up (12-month HbA1c data 7.9% for DART vs 6.9% for UCI; 52 participants; very low-quality evidence). Researchers noted small improvements in body mass index immediately after the intervention was provided and at six months, along with improved weight post intervention. Diabetes knowledge and self efficacy improved immediately following receipt of the intervention, and knowledge also at six months. The intervention did not improve blood pressure. Evidence is insufficient to show whether type 2 diabetes self management interventions for people with severe mental illness are effective in improving outcomes. Researchers must conduct additional trials to establish efficacy, and to identify the active ingredients in these interventions and the people most likely to benefit from them.

Plain-language summary: We identified one study, which recruited 64 adults with type 2 diabetes and schizophrenia or schizoaffective disorder. Researchers compared usual care plus information leaflets with a 24-week education programme delivered once a week for 90 minutes (Diabetes Awareness and Rehabilitation Training). This programme provided basic diabetes education and information about nutrition and exercise. The average age of participants was 54 years; participants had been living with type 2 diabetes for on average nine years and with their psychiatric diagnosis since they were on average 28 years old. People in the included study were monitored for six months after the programme ended. This evidence is up to date as of 07 March 2016. In summary, few studies have evaluated the effects of diabetes self management programmes for adults with severe mental illness. Study authors of the single included study did not report diabetes-related complications, all-cause mortality, adverse events, health-related quality of life nor socioeconomic effects. They described small improvements in body mass index and body weight, as well as in diabetes knowledge and self efficacy. Current evidence is insufficient to show that these types of programmes can help people with type 2 diabetes and severe mental illness to better manage their diabetes and its consequences. We rated the overall quality of the evidence as very low, mainly because of the small numbers of included studies and participants, and because reported study results showed inconsistency.