Cohort retention in seasonal malaria chemoprevention: an analysis of magnitude and associated factors in Northern Bahr el Ghazal, South Sudan
Abstract
Health interventions that require multi-dose regimens are most effective when all doses are taken. Adherence to a full three-day course of Sulfadoxine-pyrimethamine plus amodiaquine (SPAQ) in all planned cycles of the annual seasonal malaria chemoprevention (SMC) round (cohort retention) is essential for maximizing the intervention’s impact. For this study cohort retention refers to eligible children completing the full three-day course of SPAQ during all planned 5 cycles of the annual SMC round. This s tudy aimed to assess the extent of cohort retention across SMC cycles and to identify factors associated with retention among eligible children in Northern Bahr el Ghazal, South Sudan. In November 2024, a household survey was conducted in Aweil West and Aweil South counties, South Sudan, one month after the completion of the fifth cycle of SMC distribution. A multi-stage random sampling was utilized to select 1,500 child-caregiver pairs across 75 clusters (40 in Aweil West and 35 in Aweil South). Data were collected using a structured questionnaire administered using SurveyCTO. Mixed-effects modified Poisson regression modeling was employed, with statistical significance set at p < 0.05. Of the 1,500 eligible children sampled, 66.9% (95% CI: 64.4 – 69.2) were retained. Caregivers that were knowledgeable about purpose of SMC medicines (adjusted prevalence ratio (aPR):2.04; 95%CI: 1.34-3.11; P = 0.001), perceived SMC medicines as effective (aPR:4.85; 95%CI: 1.25-18.9; P = 0.023), and caregivers that had paid work (aPR: 1.28; 95%CI:1.01-1.62; P = 0.04) were significantly associated with retention. SMC cohort retention in Aweil South and West counties is strongly associated with caregivers’ trust in and knowledge of the intervention. Strengthening community engagement and increasing awareness is vital for improving retention, enhancing the intervention’s effectiveness and ultimately reducing malaria morbidity and mortality among children.