Exploring the Factors Underlying the Narrowing Urban Advantage in Child Mortality in Sub-Saharan Africa: A Scoping Review

It is widely acknowledged that child mortality rates have been higher in rural than urban areas in sub-Saharan Africa (SSA); a phenomenon appreciated as the urban advantage. However, since at least the 1980s, this urban advantage has been narrowing, and in some cases reversing across SSA. While existing studies have primarily focused on establishing this relationship, few clearly define what constitutes urban or rural, with authors using different operationalizations. Even fewer explore the underlying drivers of change. Rural and urban health outcomes are associated with both the social determinants of health and the wider political economy of health systems. This study aims to elucidate the factors underpinning the narrowing urban advantage in by examining how such factors are differentially distributed and operate across urban and rural contexts. A scoping search was conducted for English-language peer-reviewed published articles after 1990 on urban and rural child health disparities in SSA. Databases used included PubMed, Embase, and Web of Science. Overall, 21 articles were included in the scope of this review. This review adhered to PRISMA-ScR guidelines (Preferred Reporting Items for Systematic Reviews and Meta-analyses Extension for Scoping Reviews). This review examines the extent to which urban areas in SSA continue to confer a survival advantage in child mortality, and the mechanisms underlying shifts in this trend. Four key categories of determinants-environmental, healthcare-related, sociodemographic, and disease/morbidity-related-consistently emerge across the literature, though their significance and strength vary across rural and urban settings. Notably, the review identifies a growing influence of intra-urban inequality, driven by informal urbanization and the expansion of slums, as a central factor in the narrowing urban advantage. The operationalization of urbanicity and rurality was inconsistent across studies, and rigid geographical classifications often obscured important spatial and contextual nuances. These findings underscore the limitations of conventional rural-urban comparisons and highlight the need for more nuanced frameworks that reflect the complex, evolving landscape of urban poverty and child health in SSA. The spatial reconfiguration of urban poverty appears to be modifying the distribution of child health risks in manners not captured by traditional urban-rural comparisons. Future research should focus on employing an urban continuum in demographic research, accounting for intra-urban inequities within the context of rapid urbanization processes which are altering the urban health landscape, and reshaping the social determinants of child mortality across the urban-rural spectrum.