Objective To compare the value and effectiveness of different prioritization strategies of pre-exposure prophylaxis (PrEP) in New York City (NYC). Design Mathematical modeling utilized as clinical trial is not feasible. Methods Using a model accounting for both sexual and parenteral transmission of HIV we compare different prioritization strategies (PPS) for PrEP to two scenarios—no PrEP and PrEP for all susceptible at-risk individuals. The PPS included PrEP for all MSM, only high-risk MSM, high-risk heterosexuals, and injection drug users, and all combinations of these four strategies. Outcomes included HIV infections averted, and incremental cost effectiveness (per-infection averted) ratios. Initial assumptions regarding PrEP included a 44% reduction in HIV transmission, 50% uptake in the prioritized population and an annual cost per person of $9,762. Sensitivity analyses on key parameters were conducted. Results Prioritization to all MSM results in a 19% reduction in new HIV infections. Compared to PrEP for all persons at-risk this PPS retains 79% of the preventative effect at 15% of the total cost. PrEP prioritized to only high-risk MSM results in a reduction in new HIV infections of 15%. This PPS retains 60% of the preventative effect at 6% of the total cost. There are diminishing returns when PrEP utilization is expanded beyond this group. Conclusions PrEP implementation is relatively cost-inefficient under our initial assumptions. Our results suggest that PrEP should first be promoted among MSM who are at particularly high-risk of HIV acquisition. Further expansion beyond this group may be cost-effective, but is unlikely to be cost-saving.

BackgroundUpdated World Health Organization guidelines have amplified debate about how resource constraints should impact monitoring strategies for HIV-infected persons on combination antiretroviral therapy (cART). We estimated the incremental benefit and cost effectiveness of alternative monitoring strategies for east Africans with known HIV infection.MethodsUsing a validated HIV computer simulation based on resource-limited data (USAID and AMPATH) and circumstances (east Africa), we compared alternative monitoring strategies for HIV-infected persons newly started on cART. We evaluated clinical, immunologic and virologic monitoring strategies, including combinations and conditional logic (e.g., only perform virologic testing if immunologic testing is positive). We calculated incremental cost-effectiveness ratios (ICER) in units of cost per quality-adjusted life year (QALY), using a societal perspective and a lifetime horizon. Costs were measured in 2008 US dollars, and costs and benefits were discounted at 3%. We compared the ICER of monitoring strategies with those of other resource-constrained decisions, in particular earlier cART initiation (at CD4 counts of 350 cells/mm3 rather than 200 cells/mm3).ResultsMonitoring strategies employing routine CD4 testing without virologic testing never maximized health benefits, regardless of budget or societal willingness to pay for additional health benefits. Monitoring strategies employing virologic testing conditional upon particular CD4 results delivered the most benefit at willingness-to-pay levels similar to the cost of earlier cART initiation (approximately $2600/QALY). Monitoring strategies employing routine virologic testing alone only maximized health benefits at willingness-to-pay levels (> $4400/QALY) that greatly exceeded the ICER of earlier cART initiation.ConclusionsCD4 testing alone never maximized health benefits regardless of resource limitations. Programmes routinely performing virologic testing but deferring cART initiation may increase health benefits by reallocating monitoring resources towards earlier cART initiation.

Background The WHO’s 2013 revisions to its Consolidated Guidelines on ARVs will recommend routine viral load monitoring (VLM), rather than clinical or immunological monitoring, as the preferred monitoring approach on the basis of clinical evidence. However, HIV programmes in resource-limited settings require guidance on the most cost-effective use of resources given other competing priorities, including expansion of ART coverage. Here we assess the cost-effectiveness of alternative patient monitoring strategies. Methods A range of monitoring strategies was evaluated, including clinical, CD4 and viral load monitoring alone and together at different frequencies and with different criteria for switching to second-line therapies. Three independently-constructed and validated models were analysed simultaneously. Costs were estimated based on resource use projected in the models and associated unit costs; impact was quantified as disability-adjusted life years (DALYs) averted. Alternatives were compared using incremental cost-effectiveness analysis. Results All models show that clinical monitoring delivers significant benefit compared to a hypothetical baseline scenario with no monitoring or switching. Regular CD4 cell count monitoring confers a benefit over clinical monitoring alone, at an incremental cost that makes it affordable in more settings than VLM, which is currently more expensive. VLM without CD4 every six to 12 months provides the greatest reductions in morbidity and mortality, but incurs a high cost per DALY averted, resulting in lost opportunities to generate health gains if implemented instead of increasing ART coverage or expanding ART eligibility. Interpretation The priority for HIV programmes should be to expand ART coverage, firstly at CD4 <350 cells and then at CD4 <500, using lower-cost clinical or CD4 monitoring. At current costs, VLM should be considered only after high ART coverage has been achieved. Point-of-care technologies and other factors reducing costs may make VLM more affordable in future. Funding The HIV Modelling Consortium is funded by the Bill and Melinda Gates Foundation. Funding for this work was also provided by the World Health Organization.

Supplemental Digital Content is available in the text