Candidate for the Lee B. Lusted Student Prize Competition
Purpose: In a recent randomized controlled trial, daily oral preexposure chemoprophylaxis (PrEP) has been shown to be very effective for HIV prevention in men who have sex with men (MSM), and the US Centers for Disease Control and Prevention (CDC) recently provided interim guidance for its use among MSM who are at high risk for sexual acquisition of HIV. Previous studies failed to reach a consistent estimate of its cost-effectiveness.
Method: We used an epidemic modeling framework combined with detailed economic analysis to estimate costs and health outcomes for various PrEP strategies. We developed a dynamic model of the HIV epidemic among MSM aged 13-64 in the US, with annual HIV incidence of 0.8% in the base case, representing an average across the US. We assumed in the base case that PrEP reduces HIV infection risk by 73%, as seen among MSM reporting high adherence to PrEP. We estimated the number of new infections, quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratio for each strategy.
Result: If PrEP is initiated in 20% of the MSM population in the US, we estimate a reduction in new HIV infections of 21% and a gain of 893,000 QALYs over 20 years at a cost of $103,000 per QALY, given an effectiveness of 73%. Initiating PrEP in a larger proportion of the MSM population averts more infections but at increasing cost per QALY gained (more than $120,000 per QALY gained when at least 60% of the population is placed on PrEP). If PrEP is 44% effective in reducing infection risk, new HIV infections are reduced by 13% and PrEP costs $168,000 per QALY gained. PrEP has a more favorable incremental cost-effectiveness ratio in sub-groups of MSM with higher incidence, costing less than $50,000 per QALY gained when annual incidence is greater than 1.5%.
Conclusion: Use of PrEP for HIV prevention in the general MSM population is modestly expensive, but PrEP may be cost-effective by conventional standards in high-risk sub-groups of MSM.