Socioeconomic inequality and factors associated with deworming service receipt among preschool-aged children (12–59 months) in sub-Saharan Africa: a multicountry demographic and health surveys analysis (2006–2024)

Soil-transmitted helminth (STH) infections contribute substantially to anemia, physical stunting, and impaired cognitive development among young children in sub-Saharan Africa. Periodic preventive chemotherapy (“deworming”) is recommended for preschool-aged children (PSAC; 12–59 months) living in endemic communities. However, national coverage and socioeconomic equity in deworming service receipt remain unevenly characterized. This study evaluated deworming service receipt, quantified wealth-based inequality, and identified factors associated with receipt across 29 sub-Saharan African countries. We analyzed pooled cross-sectional data from 29 standard demographic and health surveys (DHS) conducted between 2006 and 2024. The descriptive sample comprised 223,594 children aged 12–59 months; the multivariable complete-case sample comprised 219,097 children (2.01% item non-response across model covariates). Complex survey design was accounted for using unique cluster identifiers (survey ID plus primary sampling unit) and normalized individual sampling weights. Wealth-based inequality was quantified using conventional Concentration Indices (CIX) and Erreygers-corrected Concentration Indices (EI), with children ranked by continuous household wealth scores. Multivariable logistic regression with country fixed effects and cluster-robust standard errors estimated adjusted odds ratios (aORs). Predicted margins and absolute risk differences were derived through marginal standardization using cluster-adjusted delta-method confidence intervals. Survey stratification was incorporated in descriptive and inequality analyses but not explicitly parameterized in the multivariable regression covariance estimation; this was acknowledged as a methodological limitation. Pooled reported deworming service receipt was 49.2% (95% CI 48.6–49.9); the unweighted equal-country average was 52.5% (95% CI 46.1–58.9). Coverage ranged from 19.6% (95% CI 17.3–22.0) in Zimbabwe to 88.9% (95% CI 87.6–90.1) in Rwanda. Only three countries achieved national coverage of 75% or higher: Rwanda (88.9%), the Republic of the Congo (81.1%), and Gabon (75.9%). The WHO 75% benchmark is operationally formulated for preventive-chemotherapy delivery within endemic implementation units and is therefore only indicatively comparable with national survey-based estimates. Socioeconomic inequality was pro-rich overall (pooled EI = 0.2362, 95% CI 0.2229–0.2494; CIX = 0.1199, 95% CI 0.1132–0.1267). Statistically significant pro-rich inequality was observed in 25 of 29 countries, with the highest EI values in Benin (0.4128) and Nigeria (0.3935). Namibia exhibited statistically significant pro-poor coverage (EI = −0.1106, 95% CI −0.1811 to −0.0402), whereas Burkina Faso, Mali, and The Gambia showed no statistically significant wealth-related concentration. In multivariable regression, maternal education (higher versus no education: aOR = 2.41, 95% CI 2.21–2.64) and household wealth (richest versus poorest: aOR = 1.91, 95% CI 1.76–2.07) were the strongest positive correlates. Older maternal age (35–49 versus 15–24 years: aOR = 1.38, 95% CI 1.31–1.45) and older child age (24–35 versus 12–23 months: aOR = 1.21, 95% CI 1.17–1.25) were positively associated with receipt, whereas higher birth order (six or more versus first-born: aOR = 0.87, 95% CI 0.82–0.92) was negatively associated. Rural residence was not independently associated with receipt after adjustment for household wealth, maternal education, and other covariates (aOR = 0.96, 95% CI 0.91–1.02). Marginal standardization revealed an adjusted absolute wealth disparity of 13.7 percentage points (richest: 56.8% [95% CI 55.6–58.0] versus poorest: 43.1% [95% CI 42.2–44.0]) and an absolute maternal-education disparity of 18.8 percentage points (higher education: 61.0% [95% CI 59.3–62.7] versus no education: 42.2% [95% CI 41.5–42.9]). Pooled reported deworming receipt among surveyed preschool children was 49.2% (equal-country average: 52.5%), with 26 of 29 countries below the WHO 75% benchmark; because that benchmark is defined for endemic implementation units, national survey estimates provide only an indicative comparison. Coverage showed pronounced pro-rich and maternal-education gradients. Because routine clinic-based delivery may not equitably reach economically disadvantaged and less-educated caregivers, national control programs may consider supplementing passive delivery with proactive, community-based outreach and routine socioeconomic-equity monitoring to support equitable implementation of WHO-recommended preventive chemotherapy.