Urban-Rural Disparities in Geographic Healthcare Accessibility: A Comparative Study of Nigeria and Zambia.

Geographic access to healthcare remains a critical barrier to health equity in low- and middle-income countries, where infrastructure and service provision are unevenly distributed. Using the UN-endorsed Degree of Urbanisation framework, we assessed disparities in geographic healthcare accessibility across Nigeria and Zambia in 2020. Travel times to health facilities were modeled for both walking and motorized transport at 1 km resolution, and stratified by settlement type and demographic group. Results showed marked urban-rural disparities: while city residents could typically reach hospitals within minutes, rural populations faced journeys exceeding 4 h on foot. Motorized transport substantially improved accessibility but remained unavailable to many, leaving only 8% of Nigeria's population and 6% of Zambia's population within a 15-min walking distance of a hospital. Children in rural Nigeria were particularly disadvantaged, with longer hospital travel times compared to reproductive-age women and elderly adults, whereas demographic differences were less pronounced in Zambia. These findings highlight persistent geographic and demographic inequalities in access to care, underscoring the need for targeted investment in rural transport networks, strategic placement of health facilities, and tailored support for vulnerable populations. By linking harmonized urban-rural classifications with demographic health needs, this study provides actionable evidence for advancing universal health coverage and reducing inequities in rapidly urbanizing African contexts.