Housing modification to prevent malaria in Uganda: an analysis of costs, willingness to pay, and equity

Innovative, equitable, and sustainable multisectoral solutions are required to address persistently high global malaria deaths, widespread insecticide and antimalarial resistance, and falling funding for malaria control. Housing modification presents a promising option. Alongside a cluster-randomized control trial in Eastern Region, Uganda, we analysed the costs and households' willingness to pay (WTP) for two housing modification interventions, screening and eave tubes, focusing on equity and scale-up potential.

Taking a disaggregated societal perspective, we assessed financial and economic costs of installing two housing modification interventions in approximately 4000 homes (20000 people). We collected WTP data through three cross-sectional household surveys (n = 1500 households each) using modified structured haggling and calculated price elasticity of demand. We used multivariable regressions and concentration indices to analyse how costs and WTP varied by household characteristics. To identify potential financing gaps, we compared WTP to costs and examined variation by household wealth quintiles.

Screening cost a mean of $116 (societal economic costs; 95%CI $112-120) United States Dollars (2022 USD) per house; eave tubes cost $50 (95%CI $48-52). When annualized over 5 years, screening cost $4.22 per person protected per year and eave tubes cost $3.03. Installation cost more in the wealthiest versus poorest quintiles for both screening ($151 vs $69) and eave tubes ($95 vs $31). Over 75% of respondents were willing to pay something for the interventions, but these values represented only a small fraction of the costs, with a higher fraction in the wealthiest vs poorest quintiles (screening: 12% vs 7%; eave tubes: 18% vs 14%).

While housing modification has relatively high upfront costs, its annual cost per person protected is comparable to other malaria interventions. Households, especially the poorest, are unwilling or unable to pay the full cost of housing modifications. Equitable scale-up would require additional financing and/or demand-boosting interventions.

NCT04622241 (clinicaltrials.gov).