Community health centres (CHCs) in South Africa play a critical role in delivering primary healthcare services to underserved populations. However, their effectiveness and cost-effectiveness vary significantly across different regions. A total of 20 community health centres in diverse geographical areas were randomly selected for this study. Data collection included patient flow, service utilization rates, and financial expenditure. A mixed-methods approach combining quantitative survey data with qualitative interviews was employed to capture comprehensive insights. The analysis revealed that CHCs operating in rural settings had a higher proportion (45%) of patients seeking services for chronic diseases compared to urban areas (20%). While the study highlights variations in patient demographics and service utilization, it underscores the need for tailored interventions to enhance efficiency. Further research should prioritise developing context-specific strategies based on regional health needs. Policy recommendations include targeted funding adjustments and workforce development programmes. Community Health Centres, Cost-Effectiveness, Randomized Field Trial, South Africa Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.