{ "background": "The systematic assessment of clinical outcomes in decentralised community health centres is critical for health systems strengthening in sub-Saharan Africa. Existing evaluations often rely on cross-sectional data, which fail to account for unobserved heterogeneity and temporal dynamics, limiting causal inference and policy relevance.", "purpose and objectives": "This review aims to critically evaluate the application of panel-data econometric methods for assessing clinical outcomes within Tanzania's community health centre system. It seeks to synthesise methodological strengths, identify common pitfalls, and propose a robust analytical framework for longitudinal health facility data.", "methodology": "A systematic search and narrative synthesis of peer-reviewed literature and grey sources was conducted. The core methodological evaluation focuses on panel-data models, notably the fixed-effects estimator specified as $Y{it} = \\alphai + \\beta X{it} + \\epsilon{it}$, where $Y{it}$ is the clinical outcome for facility $i$ at time $t$, $\\alphai$ captures time-invariant facility heterogeneity, and $X_{it}$ is a vector of time-varying covariates. Inference using cluster-robust standard errors is emphasised.", "findings": "The synthesis indicates that controlling for unobserved facility-level confounders via fixed-effects models substantially alters estimated programme impacts. A predominant theme is that analyses neglecting panel structure overstate effect sizes; for instance, one reviewed study found a reported association between drug availability and outpatient attendance halved when accounting for facility-level fixed effects. The methodological rigour of existing studies is highly variable.", "conclusion": "Panel-data methods offer a superior approach for evaluating clinical outcomes in community health settings by providing more reliable estimates of causal effects. Their adoption is essential for generating evidence that can effectively guide resource allocation and health policy.", "recommendations": "Future research should prioritise the construction and analysis of longitudinal facility datasets. Analysts must explicitly test for and model temporal dynamics and unobserved heterogeneity. Capacity building in advanced econometric techniques for health researchers is urgently needed.", "key words": "panel