We set out to review the efficacy of Community Health Worker (CHW) interventions to improve glycemia in people with diabetes.

Data sources included the Cochrane Central Register of Controlled Trials, Medline, clinicaltrials.gov, Google Scholar, and reference lists of previous publications. We reviewed randomized controlled trials (RCTs) that assessed the efficacy of CHW interventions, as compared to usual care, to lower hemoglobin A1c (A1c). Two investigators independently reviewed the RCTs and assessed their quality. Only RCTs with a follow-up of at least 12 months were meta-analyzed. A random effects model was used to estimate, from unadjusted within-group mean reductions, the standardized mean difference (SMD) in A1c achieved by the CHW intervention, beyond usual care.

Thirteen RCTs were included in the narrative review, and nine of them, which had at least 12 months of follow-up, were included in the meta-analysis. Publication bias could not be ruled-out due to the small number of trials. Outcome heterogeneity was moderate (I²= 37 %). The SMD in A1c (95 % confidence interval) was 0.21 (0.11-0.32). Meta-regression showed an association between higher baseline A1c and a larger effect size.

CHW interventions showed a modest reduction in A1c compared to usual care. A1c reduction was larger in studies with higher mean baseline A1c. Caution is warranted, given the small number of studies.