Economic evaluation of primary health care integration and targeted mass drug administration in counties in western Kenya.

Introduction: The 2025 World Health Organization (WHO) Global Report on Neglected Tropical Diseases (NTDs) highlights major progress made worldwide in controlling and eliminating these diseases. Sustaining NTD control requires cost-efficient strategies integrated into routine health systems. We evaluated the cost-effectiveness of integrating soil-transmitted helminths (STH) and schistosomiasis (SCH) treatment into routine Primary Health care (PHC) services compared with the campaign-based approach across four counties and selected sub-counties, wards, and primary health facilities in western Kenya. While the overall study assessed feasibility, treatment coverage, and economic outcomes, this manuscript evaluated the cost-effectiveness of integrating STH/SCH treatment into primary healthcare (PHC) versus campaign-based mass drug administration (MDA) in western Kenya. Methods: A quasi-experimental mixed-method study design was adopted for field-based data collection and analysis in 24 wards (12 wards for PHC-integrated, 12 wards for the campaign) across four counties. Cost data was collected from programme records. Cost parameters were informed by the WHO-CHOICE disease model, and relevant economic evaluation literature. A Markov state-transition model simulated a 5,000-person cohort over 5 years, estimating the Disability Adjusted Life Years (DALYs) averted using Global Burden of Diseases (GBD)disability weights (0.006 light, 0.024 moderate, 0.049 heavy infection). ICERs were calculated from a health system perspective. Study teams supporting both intervention arms received training to ensure consistent implementation and clear differentiation between the campaign and PHC-integrated delivery models. Results: The costing analysis showed that the campaign-based approach accounted for the largest share of program expenditures Kes 17.26 million (USD 133,814) against Kes 9.74 million (USD 75,519) for PHC integrated; a 44% reduction, largely due to its higher logistical and operational requirements, although it achieved the highest immediate treatment coverage. In contrast, the PHC-integrated model operated with lower overall costs, primarily associated with consumables and routine service delivery, while relying on existing health system infrastructure and staff including the Community health providers (CHPs). Campaign-based approach achieved higher coverage of 102.3% compared to 77.3% averting 19,230 DALYs compared to 12,840 for PHC integrated (additional 6,390 DALYs). This however translated to USD 0.25 (Kes 32.48) (cost per person treated (387,852 targeted Vs 299,960 treated) against USD 0.3 (Kes 39.54) per person treated (426,207 targeted against 436,059 treated) by the campaign approach. Economic modelling using a simulated cohort of 1,000 individuals annually over a five-year time horizon indicated that PHC integration could generate cost savings over time compared with repeated campaign delivery, highlighting its potential as a more sustainable approach for long-term disease control within routine health systems. Qualitative findings showed strong stakeholder support for PHC integration as a more sustainable and patient-centered approach than campaign-based MDA. Although MDA achieved higher coverage, PHC integration improved continuity of care through existing health system structures. Participants identified supply chain reliability, sustainable financing, digital reporting, supportive supervision, continuous capacity building, and county ownership as critical prerequisites for successful scale-up. Together, the two approaches treated 736,019 people, illustrating complementary strengths of scale versus cost efficiency. Given this evidence, our calculated ICER for campaign-based MDA, USD 9.13 per DALY averted demonstrates exceptional value for money, well below Kenya's likely willingness-to-pay threshold of about USD 2,000. Conclusion: Campaign MDA is extremely cost-effective for rapid, large-scale DALY reduction. PHC integration is more economical and sustainable for routine delivery. A hybrid approach with PHC as the backbone with periodic campaigns, optimizes both impact and sustainability. While PHC integration generated cost savings over time compared with repeated campaign approach, a cumulative 5-year DALY averted scaled to full cohort of 5,000 individuals indicates the campaign intervention averts 6,390 more DALYs than the PHC integration.