Abstract
{ "background": "Community health centres are a cornerstone of primary healthcare delivery in Tanzania, yet systematic evaluations of their operational reliability are scarce. Existing reviews often rely on conventional meta-analytic techniques that inadequately handle heterogeneous, multi-level data from diverse study designs.", "purpose and objectives": "This study aimed to methodologically evaluate the reliability of community health centre systems using a Bayesian hierarchical framework, and to derive governance-relevant inferences from the synthesised evidence.", "methodology": "A meta-analysis was conducted on studies reporting system performance metrics. A Bayesian hierarchical model was fitted to estimate the pooled reliability and study heterogeneity. The core model was $\\text{logit}(pi) = \\mu + \\alphaj[i] + \\beta Xi + \\epsiloni$, where $pi$ is the reliability proportion for observation $i$, $\\mu$ is the overall mean, $\\alphaj$ are study-level random effects, $\\beta$ represents covariate coefficients, and $\\epsilon_i$ is residual error. Posterior distributions were estimated using Markov chain Monte Carlo sampling.", "findings": "The pooled estimate for system reliability was 0.68 (95% credible interval: 0.62 to 0.73), indicating a substantial performance gap. The analysis revealed significant heterogeneity (τ = 0.41, 95% CrI: 0.28 to 0.59), with infrastructure adequacy and supply chain integrity being the most influential moderators.", "conclusion": "The Bayesian hierarchical approach provided a robust, probabilistic quantification of system reliability and its determinants, confirming that current performance is suboptimal and inconsistently reported across the literature.", "recommendations": "Governance interventions should prioritise infrastructure and supply chain reforms. Future research should adopt standardised reporting metrics to reduce measurement heterogeneity and improve evidence synthesis.", "key words": "health systems research, Bayesian meta-analysis, primary healthcare, health services research, sub-Saharan Africa", "contribution statement": "This study provides a