Effectiveness of mass screening for severe acute malnutrition using mid-upper arm circumference: a prospective regression discontinuity design

BackgroundSevere Acute Malnutrition (SAM) is a major cause of morbidity and mortality in children under five, particularly in sub-Saharan Africa. The World Health Organization (WHO) recommends using mid-upper arm circumference (MUAC) for community-based screening due to its simplicity and cost-effectiveness. This study assesses the impact of MUAC-based screening and referral by community health workers (CHWs) on nutritional status and all-cause mortality in Burkina Faso. MethodsA prospective regression discontinuity (RD) analysis was nested within the Community Health with Azithromycin Treatment (CHAT) trial, a cluster-randomized controlled trial in Nouna District, Burkina Faso. Children aged 6-59 months were screened using MUAC, and those with MUAC < 11.5 cm were referred for SAM treatment. The effect of referral on subsequent MUAC measurements and 6-month all-cause mortality was analyzed using data near the 11.5 cm threshold. Bandwidths were selected using the Imbens-Kalyanaraman (IK) algorithm to optimize bias-variance tradeoff. Generalized linear mixed-effects models were applied for analysis. ResultsOut of 65,554 children screened, 226 (0.34%) were referred for SAM. Using the IK-selected bandwidth for MUAC, no significant effects on 6-month MUAC or mortality were observed. The mean MUAC difference was 0.21 cm (95% CI: -0.22 - 0.65 cm), and the mortality odds ratio was 0.95 (95% CI: 0.03 - 31.37). Sensitivity analyses using broader bandwidths yielded consistent results. ConclusionsMUAC-based screening and referral did not significantly improve nutritional status or reduce mortality. Improving SAM referral mechanisms and integrating community health support are necessary to improve health outcomes for children with SAM. Key MessageO_LIWe evaluated whether MUAC-based community screening and referral for Severe Acute Malnutrition (SAM) improved nutritional status and reduced mortality among young children in rural Burkina Faso using a prospective regression discontinuity design. C_LIO_LIMUAC screening and referral alone did not significantly affect subsequent nutritional outcomes or all-cause mortality. C_LIO_LIThese findings highlight the importance of strengthening referral completion and integrated community-based care to ensure that screening translates into meaningful improvements in child health. C_LI