Monday, October 24, 2011: 10:48 AM
Grand Ballroom CD (Hyatt Regency Chicago)
(ESP) Applied Health Economics, Services, and Policy Research

Candidate for the Lee B. Lusted Student Prize Competition

Sabina S. Alistar, MS, Stanford University, Stanford, CA

Purpose: Pre-exposure prophylaxis with oral antiretroviral treatment (oral PrEP) for HIV-uninfected injection drug users (IDUs) is potentially useful in controlling HIV epidemics with a significant injection drug use component. The role oral PrEP in portfolios of interventions including methadone maintenance therapy (MMT) for drug users and antiretroviral treatment (ART) for infected individuals is unknown. We estimated the effectiveness and cost effectiveness of strategies for using oral PrEP (up to 50% of uninfected IDUs) in various combinations with MMT (25% of IDUs) and ART (80% of all eligible patients) in Ukraine, a representative case for mixed HIV epidemics.

Method: We expanded a previously developed dynamic compartmental model of the HIV epidemic in a population of non-IDUs, IDUs who inject opiates, and IDUs on methadone, adding an oral PrEP program (tenofovir, 50% susceptibility reduction) for uninfected IDUs. The model was populated with data from Ukraine. We modeled 1,000,000 individuals aged 15-49 stratified by HIV status and injection drug use. We analyzed packages of interventions consisting of MMT, ART and oral PrEP. We measured health care costs, quality-adjusted life years (QALYs), HIV prevalence, HIV infections averted, and incremental cost effectiveness. 

Result: Without incremental interventions, after 20 years HIV prevalence reached 67.3% in IDUs and 0.9% in non-IDUs.  A combination of MMT and oral PrEP for 25% of IDUs lowered HIV prevalence the most in both IDUs (46.2%) and the general population (0.7%). ART (80% access for eligible infected individuals), combined with MMT (25% of IDUs) and oral PrEP (25% of uninfected IDUs) averted the most infections (10,700), followed by ART (80% access) and oral PrEP (50% access), with 8,900 infections averted. The most cost-effective strategy was MMT (25% of IDUs), gaining 76,000 QALYs versus no intervention, at $530/QALY gained. The next most cost-effective strategy consisted of MMT (25% of IDUs) and ART (80% access), at $1,120/QALY gained. Further adding oral PrEP (25% access) was also cost-effective, at $12,240/QALY gained. Oral PrEP alone became cost-effective for annual PrEP costs comparable to annual HIV care costs.

Conclusion: Oral PrEP can be part of cost-effective intervention packages to control HIV epidemics where injection drug use is significant. Where budgets are limited, focusing on MMT and ART access should be the priority. Oral PrEP alone may become highly cost-effective if costs decline significantly.