District hospitals in Nigeria are pivotal healthcare facilities that serve as primary points of contact for millions of patients annually. Despite their critical role, there is limited empirical evidence on their operational effectiveness and efficiency. A mixed-method approach combining quantitative data from surveys with qualitative insights from interviews was employed. Multilevel regression models were utilised to analyse hierarchical data structures, accounting for both hospital-level and patient-level variations. The multilevel regression analysis revealed that implementing robust infection control measures significantly reduced the incidence of healthcare-associated infections (HAI) by 30% in district hospitals across Nigeria. This finding underscores the effectiveness of standardised protocols in mitigating HAI risks. This study provides valuable insights into enhancing the operational efficiency and patient safety within district hospital systems in Nigeria through evidence-based risk reduction strategies. Based on these findings, it is recommended that district hospitals in Nigeria adopt and enforce comprehensive infection control measures to further reduce HAI incidents. Additionally, ongoing training for healthcare staff in infection prevention should be prioritised. Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.