Designing equity-focused sanitation policies in Sub-Saharan Africa: the critical role of subnational data.

backgroundOpen defecation remains a major public health and equity challenge in Sub-Saharan Africa, where national averages often mask profound subnational disparities. Progress toward Sustainable Development Goal (SDG) 6.2 depends not only on increasing coverage but on closing persistent rural-urban gaps. This study quantified the magnitude and national consequences of these inequities using harmonized 2022 data.

methodsWe analyzed WHO/UNICEF Joint Monitoring Programme (JMP) 2022 estimates for 20 low- and lower-middle-income countries using four standard inequality metrics: the absolute difference (D), rate ratio (R), population attributable risk (PAR), and population attributable fraction (PAF). These indicators quantify both the scale of rural-urban gaps and the portion of the national burden attributable to rural disadvantage. Countries were grouped into a three-tier equity typology based on national prevalence and the size of the rural-urban gap.

resultsNational open-defecation prevalence ranged from 0.1% (Gambia) to 67.0% (Eritrea), with rural rates consistently and substantially higher than urban rates. In most countries, rural residents were three to ten times more likely to practise open defecation than urban residents. PAR and PAF results showed that eliminating rural disadvantage would reduce national prevalence by up to 40-60% points in the most unequal settings. Countries clustered into three profiles: high burden with extreme inequity (n = 6), moderate burden with persistent inequity (n = 10), and low burden with residual inequity (n = 4). We found that eliminating the rural disadvantage could reduce the national prevalence of open defecation by up to 40% points in the most unequal settings, demonstrating that equity is central to achieving SDG 6.2.

conclusionsOpen defecation in Sub-Saharan Africa is overwhelmingly concentrated in rural populations, making inequity, not simply low coverage, the central barrier to achieving SDG 6.2. Integrating simple equity metrics such as D, R, PAR, and PAF into national monitoring systems can help governments identify priority populations, estimate potential gains from reducing disparities, and target investments more efficiently and fairly. Equity-focused sanitation strategies are therefore essential to ensuring that no community is left behind.