{ "background": "Community health centres are pivotal for primary care delivery in sub-Saharan Africa, yet systematic evaluations of their operational systems for improving agricultural health outcomes are limited. Existing assessments often lack the methodological rigour to disentangle centre-level system effects from individual patient-level factors.", "purpose and objectives": "This intervention study aimed to methodologically evaluate the impact of a structured health systems strengthening intervention on maize yield improvement—a key nutritional determinant—among farming households registered with community health centres. The primary objective was to quantify the intervention's effect while accounting for the hierarchical data structure.", "methodology": "We conducted a clustered, non-randomised intervention study across multiple regions. The intervention comprised integrated training for health workers on agricultural health linkages and revised patient tracking systems. Data from household surveys and centre records were analysed using a three-level mixed-effects linear regression model: $Y{ij} = \\beta0 + \\beta1 T{ij} + uj + vk + \\epsilon{ij}$, where $Y{ij}$ is yield for household $i$ in centre $j$, $T{ij}$ is treatment status, $uj$ and $vk$ are centre and district random effects, and $\\epsilon{ij}$ is the residual. Inference was based on robust standard errors.", "findings": "The multilevel analysis revealed a statistically significant positive effect of the health systems intervention on maize yields. Households affiliated with intervention centres experienced an average yield increase of 17.5% (95% CI: 12.1 to 22.9) compared to control centres, after adjusting for covariates. The intra-class correlation indicated that 15% of the variation in yield was attributable to centre-level system characteristics.", "conclusion": "The findings demonstrate that targeted strengthening of community health centre systems can significantly improve agricultural yields, thereby linking health service delivery directly to food production outcomes. The methodological approach successfully isolated the system-level contribution.", "recommendations": "Policy should integrate agricultural health metrics into health centre