Urban-Rural Disparities in Health Facility Deliveries in Nigeria (2007–2021): Decomposition and Concentration Index Analyses

Background Studies have shown that high-quality services significantly improve maternal health outcomes. Despite sustained investments, disparities in service utilization remain prevalent in Nigeria. This study explores urban-rural differences and socioeconomic drivers of inequities in health facility deliveries (HFD) in Nigeria Method We used data from the third to sixth rounds of the Nigeria Multiple Indicator Cluster Surveys (2007–2021), focusing on women aged 15–49 with recent births. The study was guided by the Andersen Behavioral Model of Health Service Use. Fairlie decomposition quantified contributions to the urban–rural HFD gap, while the Wagstaff-normalized concentration index assessed socioeconomic inequality, using Stata 18. Results This analysis included 67,713 women with an average age of 33 years. Education (primary: aOR = 1.53, p < 0.001; secondary: aOR = 2.59, p < 0.001), wealth (aOR = 1.82, p < 0.001), antenatal care (aOR = 1.06, p < 0.001), age (aOR = 1.04, p < 0.001), and residence in South East (aOR = 2.41, p < 0.001) or South West (aOR = 1.31, p < 0.001) positively predicted HFD. Fairlie decomposition revealed a 16.9-percentage-point urban-rural gap, with wealth explaining 43.03%. This gap widened from 26.4% (2007) to 30.2% (2021), though wealth's contribution declined. The Wagstaff-normalized concentration index revealed significant pro-rich inequality (pooled CI = 0.597, SE = 0.006, p < 0.001). Urban areas demonstrated marginally higher inequality (CI = 0.583, SE = 0.011) compared to rural areas (CI = 0.565, SE = 0.008). Inequality peaked in 2011 (rural: CI = 0.601, SE = 0.012; urban: CI = 0.528, SE = 0.025), then diverged: rural inequality declined to CI = 0.230 (SE = 0.026) by 2021, while urban inequality rebounded from CI = 0.304 (SE = 0.024) in 2016 to CI = 0.467 (SE = 0.036) in 2021, confirming persistent wealth-based disparities in healthcare facility delivery utilization throughout the study period. Conclusion Findings underscore the need for equity-driven maternal health policies that alleviate financial barriers and address determinants of maternal healthcare access.