How do malaria testing and treatment subsidies affect drug shop client expenditures? A cross-sectional analysis in Western Kenya

OBJECTIVES: To examine how drug shop clients’ expenditures are affected by subsidies for malaria diagnostic testing and for malaria treatment, and also to examine how expenditures vary by clients’ malaria test result and by the number of medications they purchased. DESIGN: Secondary cross-sectional analysis of survey responses from a randomised controlled trial. SETTING: The study was conducted in twelve private drug shops in Western Kenya. PARTICIPANTS: We surveyed 836 clients who visited the drug shops between March 2018 and October 2019 for a malaria-like illness. This included children >1 year of age if they were physically present and accompanied by a parent or legal guardian. INTERVENTIONS: Subsidies for malaria diagnostic testing and for malaria treatment (conditional on a positive malaria test result). PRIMARY AND SECONDARY OUTCOME MEASURES: Expenditures at the drug shop in Kenya shillings (Ksh). RESULTS: Clients who were randomised to a 50% subsidy for malaria rapid diagnostic tests (RDTs) spent approximately Ksh23 less than those who were randomised to no RDT subsidy (95% CI (−34.6 to −10.7), p=0.002), which corresponds approximately to the value of the subsidy (Ksh20). However, clients randomised to receive free treatment (artemisinin combination therapies (ACTs)) if they tested positive for malaria had similar spending levels as those randomised to a 67% ACT subsidy conditional on a positive test. Expenditures were also similar by test result, however, those who tested positive for malaria bought more medications than those who tested negative for malaria while spending approximately Ksh15 less per medication (95% CI (−34.7 to 3.6), p=0.102). CONCLUSIONS: Our results suggest that subsidies for diagnostic health products may result in larger household savings than subsidies on curative health products. A better understanding of how people adjust their behaviours and expenditures in response to subsidies could improve the design and implementation of subsidies for health products. TRIAL REGISTRATION NUMBER: NCT03810014.