{ "background": "Emergency care systems in sub-Saharan Africa are underdeveloped, with a critical lack of evidence on how systemic interventions impact patient outcomes. Existing evaluations often fail to account for the hierarchical structure of clinical data, potentially biasing results.", "purpose and objectives": "This study aimed to quantify the effect of a structured emergency unit intervention—comprising protocol implementation, staff training, and essential equipment provision—on clinical outcomes in Uganda, using a multilevel analytical approach.", "methodology": "A quasi-experimental intervention study was conducted across 12 facilities. Patient-level data (n=2,847) were collected on mortality and complication rates. The primary analysis employed a three-level mixed-effects logistic regression model: $\\text{logit}(P(Y{ijk}=1)) = \\beta0 + \\beta1 X{ijk} + u{jk} + vk + \\epsilon{ijk}$, where $u{jk}$ and $v_k$ are random intercepts for clinician and facility, respectively. Robust standard errors were used for inference.", "findings": "The intervention was associated with a significant reduction in the odds of adverse outcomes (adjusted odds ratio 0.62, 95% CI 0.48 to 0.79). Specifically, a 12.3 percentage point reduction in the composite adverse outcome rate was observed in intervention facilities compared to controls.", "conclusion": "The implemented emergency care system intervention significantly improved clinical outcomes, demonstrating that targeted, system-level enhancements are effective in this resource-constrained setting.", "recommendations": "Health policy should prioritise integrated emergency care systems strengthening. Future programmes should incorporate multilevel evaluation designs to accurately attribute outcomes to complex interventions.", "key words": "health systems strengthening, multilevel modelling, clinical outcomes, quasi-experimental, sub-Saharan Africa", "contribution statement": "This paper provides a novel methodological application of multilevel regression to evaluate a complex health system intervention in Africa, generating robust evidence for its effectiveness and a replic