Application of Bayesian Spatiotemporal Logistic Regression to Child Mortality in Nigeria

This study investigates the persistent challenge of under-five mortality in Nigeria despite notable global progress in reducing child deaths. Conventional models often assume homogeneous relationships between risk factors and outcomes, neglecting spatial and temporal heterogeneity. To address this limitation, we develop a Bayesian Geographically and Temporally Weighted Logistic Regression (GTWLR) framework an extension of the Geographically and Temporally Weighted Regression (GTWR) model to binary outcomes. The Bayesian GTWLR model incorporates spatial and temporal weighting, prior knowledge, and full uncertainty quantification. Model estimation was implemented using the Integrated Nested Laplace Approximation (INLA) for computational efficiency and robust inference. Using data from the Nigeria Demographic and Health Surveys (NDHS), the model captures local variations in under-five mortality, identifies high-risk regions, and quantifies uncertainty through posterior credible intervals.This approach offers a rigorous statistical foundation for evidence-based policymaking, enabling geographically targeted interventions aligned with Sustainable Development Goal (SDG) 3.2.