Kenya trial lifts malaria testing from 7.9% to 26.7%–31.8%

At 140 pharmacies, patient and provider incentives raised testing from an 8% control baseline and reduced unnecessary antimalarial purchases.

Maria Dieci, Paul Gertler, Jonathan T. Kolstad and Carlos Paramo randomized 140 pharmacies in high-malaria-prevalence Kenyan counties among a control group and three incentive designs. Only 7.9% of transactions in control pharmacies included a rapid diagnostic test. Patient discounts increased testing by 23.9 percentage points, provider incentives by 18.8 points and combined incentives by 22.4 points; the differences among the three treatment effects were not statistically significant. Artemisinin-based combination therapy purchases fell by 8.4 to 15.3 points across the active arms, with varying statistical precision.

ContextAt least 60% of patients buying antimalarials in the study population were malaria-negative. Patient subsidies cut rapid-test prices by 90%. Provider incentives were not passed through as lower prices; pharmacists instead gave patients more explanation and treatment counseling. In the study sample, a negative test reduced the propensity to buy antimalarials from 100% to 5%. The authors estimate that each program dollar produced at least $1.32 in patient and provider welfare, a lower-bound return of 32%. Their claim that an optimized diagnosis-contingent contract delivers four times the welfare gains of free testing comes from a structural-model counterfactual, not a directly observed trial arm. This is an NBER working paper in a specific Kenyan pharmacy and malaria setting. Its broader applicability depends on local infection rates, patient beliefs, test and treatment prices, and provider behavior.