A Cost-Effectiveness Analysis of Preexposure Prophylaxis for the Prevention of HIV Among Los Angeles County Men Who Have Sex with Men
Published in: Clinical Infectious Diseases, v. 63, no. 11, Dec. 2016, p. 1495-1504
Posted on RAND.org on November 29, 2016
- What is the cost-effectiveness associated with two HIV prevention strategies, test-and-treat (expanded HIV testing plus immediate treatment) and pre-exposure prophylactic (PrEP) treatment, relative to the status quo for high-risk individuals?
Substantial gaps remain in understanding the trade-offs between the costs and benefits of choosing alternative human immunodeficiency virus (HIV) prevention strategies, including test-and-treat (expanded HIV testing combined with immediate treatment) and PrEP (initiation of preexposure prophylaxis by high-risk uninfected individuals) strategies.
We develop a mathematical epidemiological model to simulate HIV incidence among men residing in Los Angeles County, California, aged 15-65 years, who have sex with men. We combine these incidence data with an economic model to estimate the discounted cost, effectiveness (quality-adjusted life-years [QALYs]), and incremental cost-effectiveness ratios of various HIV prevention strategies using a societal perspective and a lifetime horizon.
PrEP and test-and-treat yield the largest reductions in HIV incidence, and are highly cost-effective ($27 863/QALY and $19 302/QALY, respectively) relative to status quo and at a US willingness-to-pay threshold of $150 000/QALY saved. Status quo and 12 test-and-treat and PrEP strategies determine the frontier for efficient decisions. More aggressive strategies are costlier, but more effective, albeit with diminishing returns. The relative effectiveness of PrEP is sensitive to the initial HIV prevalence rate, PrEP and antiretroviral therapy (ART) adherence and initiation rates, the probabilities of HIV transmission, and the rates of sexual partner mixing.
PrEP and test-and-treat offer cost-effective alternatives to the status quo. The success of these strategies depends on ART and PrEP adherence and initiation rates. The lack of evidence on adherence behaviors toward PrEP, therefore, warrants further studies.
- Relative to the status quo, the most efficient test-and-treat prevention strategies could cost under $25,000 per quality-adjusted life year (QALY) gained.
- The most efficient PrEP strategies could cost under $38,000 per QALY gained, relative to the status quo.
- Estimates of cost for both strategies are consistent with some studies, but much lower than others, which may be due to differences in modeling assumptions and initial HIV prevalence in other geographical settings.
- More aggressive treatments are more effective and cost more than the status quo, but these treatments also offer benefits in terms of early detection, prevention, and survival.
- Settings with constrained budgets may find the test-and-treat strategy best fits their needs; conversely settings with less constrained budgets may prefer to use the PrEP approach.