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.

BackgroundNew York City (NYC) remains an epicenter of the HIV epidemic in the United States. Given the variety of evidence-based HIV prevention strategies available and the significant resources required to implement each of them, comparative studies are needed to identify how to maximize the number of HIV cases prevented most economically.MethodsA new model of HIV disease transmission was developed integrating information from a previously validated micro-simulation HIV disease progression model. Specification and parameterization of the model and its inputs, including the intervention portfolio, intervention effects and costs were conducted through a collaborative process between the academic modeling team and the NYC Department of Health and Mental Hygiene. The model projects the impact of different prevention strategies, or portfolios of prevention strategies, on the HIV epidemic in NYC.ResultsTen unique interventions were able to provide a prevention benefit at an annual program cost of less than $360,000, the threshold for consideration as a cost-saving intervention (because of offsets by future HIV treatment costs averted). An optimized portfolio of these specific interventions could result in up to a 34% reduction in new HIV infections over the next 20 years. The cost-per-infection averted of the portfolio was estimated to be $106,378; the total cost was in excess of $2 billion (over the 20 year period, or approximately $100 million per year, on average). The cost-savings of prevented infections was estimated at more than $5 billion (or approximately $250 million per year, on average).ConclusionsOptimal implementation of a portfolio of evidence-based interventions can have a substantial, favorable impact on the ongoing HIV epidemic in NYC and provide future cost-saving despite significant initial costs.

Background HIV remains a major cause of preventable morbidity and mortality in Kenya. The effects of behaviors that accompany unhealthy alcohol consumption are a pervasive risk factor for HIV transmission and progression. Our objective was to estimate the portion of HIV infections attributable to unhealthy alcohol use and to evaluate the impact of hypothetical interventions directed at unhealthy alcohol use on HIV infections and deaths. Methods We estimated outcomes over a time horizon of 20 years using a computer simulation of the Kenyan population. This computer simulation integrates a compartmental model of HIV transmission with a mechanistic model of HIV progression that was previously validated in sub-Saharan Africa. Integration of the transmission and progression models allows simultaneous consideration of alcohol’s effects on HIV transmission and progression (e.g. lowering antiretroviral adherence may increase transmission risk by elevating viral load, and may simultaneously increase progression by increasing the likelihood of AIDS). The simulation considers important aspects of heterogeneous sexual mixing patterns, including assortativeness of partners by age and activity level, age-discordant relationships, and high activity subgroups. Outcomes included number of new HIV infections, number of AIDS deaths, and infectivity (number of new infections per infected person per year). Results Our model estimated that the effects of behaviors accompanying unhealthy alcohol consumption are responsible for 13.0% of new HIV infections in Kenya. An alcohol intervention with effectiveness similar to that observed in a published randomized controlled trial of a cognitive-behavioral therapy (CBT)-based intervention in Kenya (45% reduction in unhealthy alcohol consumption) could prevent nearly half of these infections, reducing their number by 69,858 and reducing AIDS deaths by 17,824 over 20 years. Estimates were sensitive to assumptions with respect to the magnitude of alcohol’s underlying effects on condom use, antiretroviral therapy adherence, and STI prevalence Conclusions A substantial number of new HIV infections in Kenya are attributable to unhealthy alcohol use. An alcohol intervention with the effectiveness observed in a published randomized controlled trial has the potential to reduce infections over 20 years by nearly 5 percent and avert over 15,000 deaths related to HIV.

Background Increased eligibility guidelines of antiretroviral therapy (ART) may lead to greater routine viral load monitoring. However, in resource-constrained settings, the additional resources required by greater routine viral load monitoring may impair ability to comply with expanded eligibility guidelines for ART. Objective We use a published validated computer simulation of the HIV epidemic in East African countries (expanded to include transmission as well as disease progression) to evaluate the cost–effectiveness of routine viral load monitoring. Methods We explored alternative scenarios regarding cost, frequency, and switching threshold of routine viral load monitoring (including every 6 or every 12 months; and switching thresholds of 1000, or 10 000 copies/ml), as well as alternative scenarios regarding ART initiation (200, 350, 500 cells/μl, and no CD4+ cell threshold). For each ART initiation strategy, we sought to identify the viral load monitoring strategy at which the incremental cost–effectiveness ratio (ICER) of more frequent routine viral load testing became more favorable than the ICER of more expansive ART eligibility. Cost inputs were based on data provided by the Academic Model Providing Access to Healthcare (AMPATH), and disease progression inputs were based on prior published work. We used a discount rate of 3%, a time horizon of 20 years, and a payer perspective. Results Across a wide range of scenarios, and even when considering the beneficial effect of virological monitoring at reducing HIV transmission, earlier ART initiation conferred far greater health benefits for resources spent than routine virological testing, with ICERs of approximately $1000 to $2000 for earlier ART initiation, versus ICERs of approximately $5000 to $25 000 for routine virological monitoring. ICERs of viral load testing were insensitive to the cost of the viral load test, because most of the costs originated from the downstream higher costs of later regimens. ICERs of viral load testing were very sensitive to the relative cost of second-line compared with first-line regimens, assuming favorable value when the costs of these regimens were equal. Conclusion If all HIV patients are not yet treated with ART starting at 500 cells/μl and costs of second regimens remain substantially more expensive than first-line regimens, resources would buy more population health if they are spent on earlier ART rather than being spent on routine virological testing.

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