Pharmaceutical intervention for hypertension in a rural district of the Republic of Zambia: a model-based economic evaluation.

Objectives: In Zambia, 19.1% of the adult population had elevated blood pressure. Hence, the Ministry of Health in Zambia designated the improvement of hypertension (HTN) care services as a priority policy. However, there are limited data on cost-effective interventions to address HTN and their budget impact in sub-Saharan Africa. The objective of this paper is to investigate the cost-effectiveness of primary-level interventions for HTN (pharmaceutical treatments) compared with no treatment, and the budget impact, in the Chongwe District, rural Zambia.

Methods: A cost-utility analysis was undertaken from the perspective of healthcare provider, employing a cohort Markov model with a lifetime horizon. The model was developed and populated with evidence from the literature, including novel locally collected cost data. The analysis was run for the overall population aged 40 years and above and for subpopulations stratified by three levels of risk and gender in Chongwe District by using cost data directly collected. A probabilistic analysis was performed to assess the probability of cost-effectiveness.

Results: The dominant treatment for the general population was a combination therapy of diuretics and calcium blockers. The incremental cost-effectiveness ratio was US$1114 compared with no treatment. This was the most cost-effective first-line medication for HTN for all subgroup populations, except for the subgroups classified as low-risk defined by WHO. The estimated annual budget impact was US$1 015 605 in total if all HTN patients in Chongwe District received the most cost-effective treatment. Considering only material costs, the annual total budget was US$29 435.

Conclusion: The most cost-effective first-line medication for HTN in rural Zambia was the combination therapy of diuretics and calcium blockers for the general population. From the perspective of budget impact, local government could need to secure approximately US$30 000 to facilitate the delivery of the most cost-effective HTN medications to the entire population over 40 years in need.