The effect of supervision on community health workers' effectiveness with households in rural South Africa: A cluster randomized controlled trial

Background Community health workers (CHWs) can supplement professional medical providers, especially in rural settings where resources are particularly scarce. Yet, outcomes of studies evaluating CHWs effectiveness have been highly variable and lack impact when scaled nationally. This study examines if child and maternal outcomes are better when existing government CHWs, who are perinatal home visitors, receive ongoing enhanced supervision and monitoring, compared to standard care.Methods and findings A cluster randomized controlled effectiveness trial was conducted comparing outcomes over 2 years when different supervision and support are provided. Primary health clinics were randomized by clinic to receive monitoring and supervision from either (1) existing supervisors (Standard Care (SC); n = 4 clinics, 23 CHWs, 392 mothers); or (2) supervisors from a nongovernmental organization that provided enhanced monitoring and supervision (Accountable Care [AC]; n =4 clinic areas, 20 CHWs, 423 mothers). Assessments were conducted during pregnancy and at 3, 6, 15, and 24 months post-birth with high retention rates (76% to 86%). The primary outcome was the number of statistically significant intervention effects among 13 outcomes of interest; this approach allowed us to evaluate the intervention holistically while accounting for correlation among the 13 outcomes and considering multiple comparisons. The observed benefits were not statistically significant and did not show the AC's efficacy over the SC. Only the antiretroviral (ARV) adherence effect met the significance threshold established a priori (SC mean 2.3, AC mean 2.9, p < 0.025; 95% CI = [0.157, 1.576]). However, for 11 of the 13 outcomes, we observed an improvement in the AC compared to the SC. While the observed outcomes were not statistically significant, benefits were observed for 4 outcomes: increasing breastfeeding for 6 months, reducing malnutrition, increasing ARV adherence, and improving developmental milestones. The major study limitation was utilizing existing CHWs and being limited to a sample of 8 clinics. There were no major study-related adverse events. Conclusions Supervision and monitoring were insufficient to improve CHWs' impact on maternal and child outcomes. Alternative strategies for staff recruitment and narrowing the intervention outcomes to the specific local community problems are needed for consistently high impact.