{ "background": "Community health centres are a critical component of the primary healthcare system in Kenya, yet systematic assessments of their operational reliability are limited. Methodological rigour in evaluating their performance over time, particularly using longitudinal data, requires critical examination to inform evidence-based health systems strengthening.", "purpose and objectives": "This systematic review aims to evaluate the methodological approaches, specifically panel-data estimation techniques, used in empirical studies assessing the reliability of community health centre systems in Kenya. It seeks to catalogue the statistical models employed, appraise their appropriateness for health systems research, and identify prevalent methodological gaps.", "methodology": "A systematic search of multiple electronic databases was conducted following PRISMA guidelines. Peer-reviewed studies employing panel-data methods to analyse health centre performance metrics were included. Studies were critically appraised for their methodological design, model specification, and handling of panel-data complexities such as unobserved heterogeneity.", "findings": "The review identified a predominant reliance on basic static panel models, with over 60% of included studies employing a fixed-effects specification of the form $Y{it} = \\alphai + \\beta X{it} + \\epsilon{it}$. A key methodological shortcoming was the frequent failure to account for serial correlation, with fewer than 20% of studies reporting robust standard errors or conducting necessary diagnostic tests. This omission potentially biases inference on the determinants of system reliability.", "conclusion": "Current applications of panel-data econometrics in this domain are often methodologically simplistic, potentially compromising the validity of findings on health system performance and reliability. There is a significant gap in the use of dynamic models and rigorous error-structure analysis.", "recommendations": "Future research should adopt more sophisticated dynamic panel models and explicitly test for and address common panel-data issues. Capacity building in advanced longitudinal data analysis for health systems researchers is urgently needed. Journal editors and peer reviewers should enforce stricter methodological reporting standards.", "key words": "health systems research, panel data, econometric methods, primary healthcare, health services reliability, Kenya",