The cost-effectiveness of preexposure prophylaxis for HIV prevention in the United States in men who have sex with men

Abstract

Background: A recent randomized, controlled trial showed that daily oral preexposure chemoprophylaxis (PrEP) was effective for HIV prevention in men who have sex with men (MSM). The Centers for Disease Control and Prevention recently provided interim guidance for PrEP in MSM at high risk for HIV. Previous studies did not reach a consistent estimate of its cost-effectiveness.

Objective: To estimate the effectiveness and cost-effectiveness of PrEP in MSM in the United States.

Design: Dynamic model of HIV transmission and progression combined with a detailed economic analysis.

Data sources: Published literature.

Target population: MSM aged 13 to 64 years in the United States.

Time horizon: Lifetime.

Perspective: Societal.

Intervention: PrEP was evaluated in both the general MSM population and in high-risk MSM and was assumed to reduce infection risk by 44% on the basis of clinical trial results.

Outcome measures: New HIV infections, discounted quality-adjusted life-years (QALYs) and costs, and incremental cost-effectiveness ratios.

Results of base-case analysis: Initiating PrEP in 20% of MSM in the United States would reduce new HIV infections by an estimated 13% and result in a gain of 550,166 QALYs over 20 years at a cost of $172,091 per QALY gained. Initiating PrEP in a larger proportion of MSM would prevent more infections but at an increasing cost per QALY gained (up to $216,480 if all MSM receive PrEP). Preexposure chemoprophylaxis in only high-risk MSM can improve cost-effectiveness. For MSM with an average of 5 partners per year, PrEP costs approximately $50,000 per QALY gained. Providing PrEP to all high-risk MSM for 20 years would cost $75 billion more in health care-related costs than the status quo and $600,000 per HIV infection prevented, compared with incremental costs of $95 billion and $2 million per infection prevented for 20% coverage of all MSM.

Results of sensitivity analysis: PrEP in the general MSM population would cost less than $100,000 per QALY gained if the daily cost of antiretroviral drugs for PrEP was less than $15 or if PrEP efficacy was greater than 75%.

Limitation: When examining PrEP in high-risk MSM, the investigators did not model a mix of low- and high-risk MSM because of lack of data on mixing patterns.

Conclusion: PrEP in the general MSM population could prevent a substantial number of HIV infections, but it is expensive. Use in high-risk MSM compares favorably with other interventions that are considered cost-effective but could result in annual PrEP expenditures of more than $4 billion.

Primary funding source: National Institute on Drug Abuse, Department of Veterans Affairs, and National Institute of Allergy and Infectious Diseases.

Figure 1. Cost-Effectiveness of PrEP for HIV Prevention

Incremental costs and quality-adjusted life years (QALYs) are plotted for each PrEP use scenario in the general MSM population and in high-risk MSM, with the origin corresponding to the status quo of no PrEP. The lines show the incremental cost-effectiveness ratio relative to the next lower level of PrEP use (the preceding scenario with a lower percentage of MSM starting PrEP). Under each PrEP use scenario, individuals initiate PrEP immediately and remain on PrEP for the 20-year time horizon or until they turn 65. PrEP is assumed to be 44% effective and cost $10,083 per year, inclusive of monitoring costs. Incremental costs and QALYs are calculated over a 20-year time horizon and are discounted to the present at 3% annually. Note: H–R = high-risk, PrEP = preexposure prophylaxis, MSM = men who have sex with men.

Figure 2. Cost-Effectiveness of PrEP for HIV Prevention as a Function of PrEP Efficacy and Cost

(a) This two-way sensitivity analysis shows ranges of the incremental cost-effectiveness ratio for initiating 20% of the general MSM population on PrEP as a function of PrEP efficacy and cost. Costs depicted on the vertical axis are annual and include all ARV and monitoring costs. The horizontal axis denotes PrEP efficacy, measured as the percentage reduction in the probability of an uninfected individual acquiring HIV infection from an infected individual. The color at each point signifies the incremental cost-effectiveness ratio for that PrEP efficacy and cost. For example, the incremental cost-effectiveness ratio is less than $100,000/quality-adjusted life year (QALY) gained when PrEP efficacy is greater than 75% or when efficacy is at least 40% and costs are less than $5,427 per year. Incremental costs and QALYs used to calculate the incremental cost-effectiveness ratios are calculated over a 20-year time horizon and are discounted to the present at 3% annually. (b) This two-way sensitivity analysis shows ranges of the incremental cost-effectiveness ratio for initiating all high-risk MSM on PrEP as a function of PrEP efficacy and cost. Costs depicted on the vertical axis are annual and include all ARV and monitoring costs. The horizontal axis denotes PrEP efficacy, measured as the percentage reduction in the probability of an uninfected individual acquiring HIV infection from an infected individual. The color at each point signifies the incremental cost-effectiveness ratio for that PrEP efficacy and cost. For example, at our base-case cost, the incremental cost-effectiveness ratio is less than $100,000/QALY gained as long as PrEP efficacy is greater than 22%. Incremental costs and QALYs used to calculate the incremental cost-effectiveness ratios are calculated over a 20-year time horizon and are discounted to the present at 3% annually. Note: PrEP = preexposure prophylaxis, MSM = men who have sex with men, ICER = incremental cost-effectiveness ratio.