Comparative effectiveness and cost-effectiveness of antiretroviral therapy and pre-exposure prophylaxis for HIV prevention in South Africa

Abstract

BackgroundAntiretroviral therapy (ART) and oral pre-exposure prophylaxis (PrEP) are effective in reducing HIV transmission in heterosexual adults. The epidemiologic impact and cost-effectiveness of combined prevention approaches in resource-limited settings remain unclear.MethodsWe develop a dynamic mathematical model of the HIV epidemic in South Africa’s adult population. We assume ART reduces HIV transmission by 95% and PrEP by 60%. We model two ART strategies: scaling up access for those with CD4 counts ≤ 350 cells/μL (Guidelines) and for all identified HIV-infected individuals (Universal). PrEP strategies include use in the general population (General) and in high-risk individuals (Focused). We consider strategies where ART, PrEP, or both are scaled up to 100% of remaining eligible individuals yearly. We measure infections averted, quality-adjusted life-years (QALYs) gained and incremental cost-effectiveness ratios over 20 years.ResultsScaling up ART to 50% of eligible individuals averts 1,513,000 infections over 20 years (Guidelines) and 3,591,000 infections (Universal). Universal ART is the most cost-effective strategy at any scale ($160-$220/QALY versus comparable scale Guidelines ART expansion). General PrEP is costly and provides limited benefits beyond ART scale-up ($7,680/QALY to add 100% PrEP to 50% Universal ART). Cost-effectiveness of General PrEP becomes less favorable when ART is widely given ($12,640/QALY gained when added to 100% Universal ART). If feasible, Focused PrEP is cost saving or highly cost effective versus status quo and when added to ART strategies.ConclusionsExpanded ART coverage to individuals in early disease stages may be more cost-effective than current guidelines. PrEP can be cost-saving if delivered to individuals at increased risk of infection.

Cost-effectiveness of Injectable Preexposure Prophylaxis for HIV Prevention in South Africa

“…As a result, we cannot directly compare their findings to ours for age-prioritized PrEP under different modeling assumptions. Our data were also similar to those of Alistar et al [39], who predicted that unprioritized oral PrEP may cost $1172 per quality-adjusted life-year gained in South Africa whereas risk-prioritized PrEP was potentially cost-saving. Pretorius et al [40] predicted that 90% effective PrEP prioritized to South African women aged 25-35 years may cost over $20 000 per infection prevented over 10 years.…”

Evaluating the impact of pulse oximetry on childhood pneumonia mortality in resource-poor settings

“…PO1 and PO2 are most cost-effective in Niger ($3.72 and $2.97 per DALY, respectively), the Democratic Republic of the Congo ($6.81 and $4.81 per DALY, respectively) and Ethiopia ($6.57 and $5.00 per DALY, respectively), partly driven by the comparatively lower costs of hospital care in those countries. For comparison, an insecticide-treated mosquito net (ITN) to prevent malaria is estimated to cost between $5 and $31 per DALY averted 19 , whereas HIV antiretroviral therapy has been estimated to cost upwards of $150 per DALY averted 20 . …”

Modeling and Cost-Effectiveness in HIV Prevention

“…Microbicide gels used by women on a per sex-act basis have one of the lowest reported ICERs with $297/DALY averted in South Africa, assuming 54% efficacy in HIV prevention and use in 72% of sex acts [47]. Another study examined both PrEP and ART scale-up; it suggests universal ART is the most cost-effective strategy and that oral PrEP with 60% efficacy provided to all HIV-uninfected adults in South Africa would provide few benefits beyond ART scale-up, but that PrEP focused to the highest risk individuals could be cost-saving compared to the status quo [48]. In serodiscordant couples, an estimated ICER for PrEP plus increased ART coverage in Uganda is $5,354/DALY averted [49], and in South Africa a similar intervention – with inclusion of ART initiation among eligible serodiscordant partners – has an ICER of $10,383/DALY averted [50].…”

“…Importantly, these results excluded the costs of case identification and the frequent testing required to identify participants with high CD4 counts. Results of a different study implementing TasP for all HIV-infected adults in South Africa were also very cost-effective with an ICER between $160-$220/QALY gained and more favorable than providing PrEP to the HIV-negative population (also noted above) [48]. A study based in Uganda found expanding ART to 55% of serodiscordant couples resulted in an incremental cost per infection averted of $1,452 [49].…”