Community health centres in Ethiopia are crucial for providing healthcare services to underserved populations. However, their reliability and effectiveness vary significantly across different regions. A mixed-method approach was employed, including quantitative data analysis through statistical regression models and qualitative interviews. The study used a difference-in-differences (DID) model for causal inference. The DID model revealed a significant positive effect of implementing standardised training programmes on service quality improvement in community health centres by 25%. The quasi-experimental design provided robust evidence for the reliability and effectiveness of community health centre systems, with specific contributions to policy-making and resource allocation. Standardised training programmes should be prioritised to enhance service quality uniformly across all community health centres in Ethiopia. Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.