Background: Improved prevention and management of vascular disease is a global priority. Non-health care professionals (such as, 'lay health workers' and 'peer support workers') are increasingly being used to offer telephone support alongside that offered by conventional services, to reach disadvantaged populations and to provide more efficient delivery of care. However, questions remain over the impact of such interventions, particularly on a wider range of vascular related conditions (such as, chronic kidney disease), and it is unclear how different types of telephone support impact on outcome. This study assessed the evidence on the effectiveness and cost-effectiveness of telephone self-management interventions led by 'lay health workers' and 'peer support workers' for patients with vascular disease and long-term conditions associated with vascular disease.

Methods: Systematic review of randomised controlled trials. Three electronic databases were searched. Two authors independently extracted data according to the Cochrane risk of bias tool. Random effects meta-analysis was used to pool outcome measures.

Results: Ten studies were included, primarily based in community settings in the United States; with participants who had diabetes; and used 'peer support workers' that shared characteristics with patients. The included studies were generally rated at risk of bias, as many methodological criteria were rated as 'unclear' because of a lack of information.Overall, peer telephone support was associated with small but significant improvements in self-management behaviour (SMD = 0.19, 95% CI 0.05 to 0.33, I2 = 20.4%) and significant reductions in HbA1c level (SMD = -0.26, 95% CI -0.41 to -0.11, I2 = 47.6%). There was no significant effect on mental health quality of life (SMD = 0.03, 95% CI -0.12 to 0.18, I2 = 0%). Data on health care utilisation were very limited and no studies reported cost effectiveness analyses.

Conclusions: Positive effects were found for telephone self-management interventions via 'lay workers' and 'peer support workers' for patients on diabetes control and self-management outcomes, but the overall evidence base was limited in scope and quality. Well designed trials assessing non-healthcare professional delivered telephone support for the prevention and management of vascular disease are needed to identify the content of effective components on health outcomes, and to assess cost effectiveness, to determine if such interventions are potentially useful alternatives to professionally delivered care.