District hospitals in Nigeria play a crucial role in providing primary health care services to underserved populations. However, their operational efficiency and cost-effectiveness are often underexplored. A mixed-methods approach was employed, combining quantitative data from financial records and qualitative insights through interviews with healthcare professionals. The quasi-experimental design involved comparing pre- and post-intervention metrics to assess changes in service delivery efficiency. District hospitals showed a significant decrease (35%) in patient wait times after implementing new scheduling protocols, though variability in resource allocation across districts remained substantial. While improvements were noted, further systematic interventions are required to address broader systemic issues affecting cost-effectiveness. Investment in standardised training programmes for staff and infrastructure upgrades is recommended to enhance long-term efficiency and service quality. District Hospitals, Quasi-Experimental Design, Cost-Effectiveness, Nigeria Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.