Cost-Effectiveness of Using Conditional Economic Incentives to Improve Pre-exposure Prophylaxis Adherence Among Male Sex Workers

Introduction Conditional economic incentives can improve medication-taking behaviors among populations at risk of contracting human immunodeficiency virus (HIV). However, there are no data on the cost-effectiveness of incentive programs for improving pre-exposure prophylaxis (PrEP) adherence among male sex workers (MSWs) who have one of the highest HIV acquisition rates. Our objective was to assess the cost-effectiveness of incentive programs to improve adherence to pre-exposure prophylaxis (PrEP) among male sex workers Methods We conducted an economic evaluation of the PrEP Seguro randomized pilot trial in Mexico (ClinicalTrials.gov: NCT03674983). Among n = 110 MSWs, those randomized to the intervention received tiered incentives based on PrEP drug levels in scalp hair measured at three clinic visits over 6 months. The intervention led to a 28.7% increase in scalp hair PrEP concentration, consistent with increased adherence (p = 0.05). Here we use a micro-costing approach from the health system perspective to calculate costs. Quality-adjusted life years (QALYs) were estimated from the number of HIV infections averted through sufficient PrEP adherence (tenofovir concentration > 0.011 ng/mg corresponding to greater than or equal to three weekly doses). Incremental cost-effectiveness ratios (ICERs) estimated the cost/QALY gained owing to the intervention. Results The mean cost per patient was US $165.53 and $179.55 among standard care and incentive patients, respectively. Over 6 months of follow-up, 62% of standard care patients and 78% of incentive recipients were PrEP adherent. After the program, the lifetime average QALYs gained per infection avoided were 9.17 (minimum, maximum: 7.5, 10.8) and 9.84 (minimum, maximum: 8.05, 11.6) among standard care and incentive patients, respectively. The 6-month ICER was US $20.92/QALY gained by the intervention, which was highly cost-effective at a willingness-to-pay of US $8655 (Mexico's 2020 per capita gross domestic product (GDP)). Discussion Using behavioral economics approaches for enhancing adherence to HIV prevention may offer health and fiscal benefits through reduced HIV incidence. Fully powered implementation trials can determine future cost-effectiveness of scaling up incentives for PrEP adherence among high-risk populations.