Emergency care units (ECUs) in Nigeria are crucial for managing acute medical emergencies effectively. A systematic literature search was conducted using databases such as PubMed, Scopus, and Web of Science. Studies published between and were included based on specific criteria related to ECU functionality and patient outcomes. The analysis revealed a significant improvement in patient survival rates (p < 0.05) when ECUs utilised an evidence-based triage system, with a proportion of 78% showing better clinical outcomes compared to non-ECU hospitals. ECU systems in Nigeria have demonstrated promising clinical outcomes but require further methodological validation and standardization for widespread adoption. Standardised training programmes and regular audits should be implemented to ensure consistent quality of care across all ECUs. Data sharing initiatives between facilities can facilitate benchmarking and continuous improvement. Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.