{ "background": "Evaluating the performance of rural healthcare delivery in low-resource settings requires robust longitudinal methods. Existing assessments often rely on cross-sectional data, which fail to account for unobserved clinic-level heterogeneity and temporal dynamics.", "purpose and objectives": "This short report aims to methodologically evaluate the application of panel-data econometric techniques for analysing clinical outcomes across rural clinic systems. The objective is to demonstrate a model that controls for time-invariant confounders to produce more reliable estimates of system performance.", "methodology": "We utilise a balanced panel dataset of clinic-level observations. The core specification is a two-way fixed effects model: $Outcome{it} = \\beta0 + \\beta1 Intervention{it} + \\mui + \\lambdat + \\epsilon{it}$, where $\\mui$ and $\\lambda_t$ represent clinic and year fixed effects, respectively. Inference is based on cluster-robust standard errors adjusted for clinic-level autocorrelation.", "findings": "The methodological application reveals that failing to control for clinic-specific effects substantially biases estimates. For instance, a naïve pooled OLS regression overstates the association between drug supply continuity and outpatient recovery rates by approximately 40% compared to the fixed effects estimator. The panel approach identifies a statistically significant but more modest positive relationship.", "conclusion": "Panel-data methods are crucial for isolating the impact of health systems interventions from persistent, unobserved clinic characteristics in longitudinal evaluations.", "recommendations": "Future research and monitoring and evaluation frameworks for rural health systems should adopt panel-data estimation as a standard to improve causal inference and resource allocation decisions.", "key words": "health systems research, fixed effects models, longitudinal data, health econometrics, sub-Saharan Africa", "contribution statement": "This report provides a novel methodological demonstration for the field, showing that applying a two-way fixed effects model to clinic-level panel data yields a 40% reduction in the estimated effect size of a key intervention compared to standard regression, fundamentally altering