The 1,7-malaria reactive community-based testing and response (1,7-mRCTR) approach in Tanzania: a cost-effectiveness analysis

Abstract Background: Reactive case detection (RACD) for malaria control has been found effective in low transmission settings, but its impact and cost-effectiveness in moderate-high transmission settings are unknown. We conducted an economic evaluation alongside an empirical trial of a modified RACD strategy (1,7-mRCTR) in three high malaria transmission districts in Tanzania. Methods: The costs and cost-savings associated with the intervention to passive case detection alone were estimated, and a simulation model was utilized to assess cost-effectiveness in terms of incremental cost-effectiveness ratios (ICERs) for multiple endpoints. Empirical cost data were collected using household surveys. Only intervention-related programmatic costs were included in this analysis. The incremental costs of the intervention were calculated from under a societal perspective. Costs are reported in 2022 US dollars. The proximal health effects of the intervention were calculated using trial data and malaria registers. OpenMalaria, an open-source microsimulation model, was used to simulate unobserved and distal health effects of the intervention. The model was fit to baseline malaria prevalence and estimated percentage point decline in malaria prevalence from the corresponding impact evaluation. Cost-effectiveness endpoints include the incremental cost per: (i) person treated, (ii) additional malaria case detected using a combination of passive and reactive case detection, (iii) incident malaria case averted, (iv) malaria death averted, and (v) DALY averted. Propagated uncertainty was assessed via 2nd-order Monte Carlo simulation, including bootstrapping of empirical data distributions. Incremental costs per DALY averted were compared to a willingness-to-pay threshold based on estimated opportunity costs of healthcare spending in Tanzania. Results: The programmatic cost of the 1,7-mRCTR intervention was $5327 per 1000 population. The combination of reactive and passive case detection in the intervention arm resulted in an additional 445 malaria cases detected per 1000 compared to passive detection alone, yielding an incremental cost per additional case detected of $11.97. For distal health outcomes, the ICER associated with the 1,7-mRCTR intervention is $14,887 per death averted and $163 per DALY averted. Conclusions: The 1,7-mRCTR intervention appears to be cost-effective under a willingness-to-pay threshold of $417 per DALY averted, showing that modified RACD strategies can provide value for money in high transmission settings.