{ "background": "District hospitals in sub-Saharan Africa face systemic inefficiencies, yet evidence on scalable interventions to improve operational performance remains limited. Current assessments often rely on observational data, lacking rigorous causal evaluation of integrated system reforms.", "purpose and objectives": "This study aimed to quantify the causal impact of a bundled intervention combining diagnostic capacity enhancement with governance restructuring on hospital efficiency. The primary objective was to measure gains in patient throughput and resource utilisation.", "methodology": "We conducted a stratified, parallel-group randomised field trial across 42 district hospitals. Facilities were randomised to receive the integrated intervention or continue standard practice. Efficiency was measured using a stochastic frontier analysis model: $\\ln(Output{it}) = \\beta0 + \\beta\\ln(Input{it}) + v{it} - u{it}$, where $v{it}$ is noise and $u_{it}$ represents inefficiency. Primary outcomes were the technical efficiency score and average length of stay, analysed using intention-to-treat with cluster-robust standard errors.", "findings": "The intervention group showed a significant increase in mean technical efficiency (0.72 vs. 0.61, p<0.01). The adjusted difference was 0.09 (95% CI: 0.03 to 0.15). A key theme from process data was that governance changes enabled more responsive reallocation of diagnostic resources.", "conclusion": "The integrated diagnostic and governance intervention produced a statistically significant improvement in hospital efficiency. This demonstrates that concurrently addressing technical and managerial constraints is effective.", "recommendations": "Policy should prioritise bundled technical-governance reforms over singular investments. Future implementation requires tailored support for governance restructuring to sustain diagnostic gains.", "key words": "health systems, stochastic frontier analysis, operational research, resource allocation, health policy, randomised trial", "contribution statement": "This paper provides the first causal evidence from a field trial on the efficiency gains of bundling diagnostic and governance interventions in district hospitals, introducing