Bohdan Nosyk, PhD, on Ending the US HIV Epidemic
New findings published in The Lancet HIV have shed light on steps needed to reach national targets by 2030 in the Ending the HIV Epidemic initiative.
In their economic modeling study, the researchers examined 23,040 combinations of 16 evidence-based interventions including HIV prevention, treatment, testing, engagement, and re-engagement.
They used a dynamic HIV transmission model calibrated with the best available evidence on structural and epidemiological conditions in 6 cities in the United States including Atlanta, Georgia; Baltimore, Maryland; Los Angeles, California; Miami, Florida; New York, New York; and Seattle, Washington. According to the researchers, these 6 cities account for nearly a quarter of all people living with HIV in the United States.
The main outcomes of the study were defined as averted HIV infections, quality-adjusted life-years (QALYs), total costs (in 2018 US dollars), and incremental cost-effectiveness ratios (ICER).
For each city, the researchers identified combination strategies that offered the greatest health benefits while still remaining cost-effective. Each city required a unique mix of treatment and prevention strategies between 9 individual interventions in Seattle and 13interventions in Miami. They noted that the implementation of these strategies at previously documented scale-up could reduce the incidence of HIV by between 30.7% (Seattle) and 50.1% (New York City) by 2030, at ICERs that ranged from cost-saving in cities like Atlanta, Baltimore, and Miami, to $95,416 per QALY in Seattle.
Implementing these combination intervention strategies at ideal levels was associated with HIV incidence reductions from 39.5% in Seattle to 83.6% in Baltimore. Although the total costs of implementation of these strategies across the cities at previously documented scale-up were projected to reach $559 million per year in 2024, these costs would be offset by long-term reductions in new HIV infections and delayed disease progression. In fact, Atlanta, Baltimore, and Miami projected cost savings between 2020 and 2040, the researchers noted.
The researchers concluded that, although evidence-based biomedical interventions can offer significant public health and economic value, these interventions must be accompanied by strategies geared towards overcoming social and structural barriers to HIV care.
Infectious Diseases Consultant discussed the implications of these findings further with lead study author Bohdan Nosyk, PhD, with the British Columbia Centre for Excellence in HIV/AIDS in Canada.
ID CON: In your paper, you and you colleagues noted that the HIV epidemic in the United States is a collection of diverse local microepidemics. Could you elaborate on this?
Dr Nosyk: The US HIV epidemic is not a homogenous national epidemic; rather, it is characterized by distinct microepidemics concentrated in so-called hotspot counties or cities, each with their own distinct demographic profiles and, importantly, differences in access to the tools available to combat the spread of HIV/AIDS, including needle exchange, pre-exposure prophylaxis (PrEP) and, of course, antiretroviral treatment. These factors have combined to create very different epidemics in places like Seattle and Miami, for instance, which are at the extremes among the cities we studied in terms of new HIV diagnoses.
ID CON: Could you describe some of the individual interventions for HIV reduction that were implemented into the cities assessed in your study, and some of the positive effects vs limitations you observed for each in their respective areas?
Dr Nosyk: We considered 6 different HIV testing interventions, delivered in different healthcare settings or through automated reminders through electronic medical records systems. Testing is cheap, and the benefits to early detection are substantial, so we found these interventions would save money over the long-term in most settings. We need to increase HIV testing by any means available.
PrEP was another strategy we considered, and we observed very different results across cities. In places like Seattle and New York, who have already made PrEP widely available and also have relatively smaller pools of undiagnosed or untreated people living with HIV/AIDS, we found that the value of further scaling up access to PrEP in a combination implementation strategy was not cost-effective. Its benefits did not outweigh the substantial costs of providing it, particularly if racial disparities in access aren’t reduced, which was a conservative assumption of our analysis. In cities like Atlanta or Miami, however, where there are considerably larger numbers of people with detectable virus and where PrEP is not as widely available, PrEP was highly cost-effective and would be a major difference-maker in the course of their epidemics.
ID CON: In your article, you and your colleagues noted that “complementary strategies to overcome social and structural barriers to HIV care will be required to reach national targets of the ending the HIV epidemic initiative by 2030.” Could you discuss some of these barriers and how they could potentially be overcome?
Dr Nosyk: Expanding health insurance coverage is a key factor, and expanding the reach of the Ryan White HIV/AIDS Program is a ready solution. However, there are other barriers including health system capacity constraints, particularly in the southern United States: the significant stigma still surrounding HIV, and gaps in health literacy that are preventing young gay men in particular from accessing PrEP. These are all factors that drive the wide differences in HIV incidence in whites compared with blacks and Hispanics in the United States.
ID CON: What key clinical takeaways do you hope to leave with infectious disease specialists and other health care practitioners treating HIV?
Dr Nosyk: Our results highlight the need for the limited human resources we have available to us to be delivered to the right places and the right people at the right time. The COVID-19 pandemic has raised the public’s awareness about the scarcity of resources–not just financial resources, but human resources–available in the health care system.
We need to be strategic about how we use these resources to ensure they are making the greatest possible impact. Our recommended strategies would require substantial staffing to ensure adequate implementation, particularly for labor-intensive interventions to diagnose and maintain people living with HIV/AIDS in treatment. These need to be accounted for as each county approaches its HIV/AIDS response.
Finally, our estimates are conservative; they focus solely on the direct health system costs of delivering the biomedical interventions we considered. Greater resources and efforts will be required to promote health literacy, reduce stigma and reach more marginalized and hard-to-reach populations.
ID CON: What are the next steps in terms of future research in this area?
Dr Nosyk: To date, my colleagues and I have made the assumption in our work that interventions are scaled up across racial/ethnic groups in proportion with current levels of access to care–in other words, no explicit focus on reducing disparities in healthcare access. It was a conservative assumption that we imposed particularly because it should not be expected that this will happen naturally.
We now want to focus on the potential impact of strategies designed explicitly to eliminate these disparities. Reducing these disparities is more difficult given the greater HIV prevalence among black and Hispanic men who have sex with men, and the greater likelihood of having relationships with partners from one’s own racial/ethnic group. This means that the preventive benefits one receives from available interventions do not necessarily translate across racial/ethnic groups. Thus, it is very important that we reach the groups most affected–young, black and Hispanic men who have sex with men in particular. These are going to be the key hurdles we need to cross if we are to meet the ambitious targets of the ‘Ending the HIV Epidemic’ strategy.
—Christina Vogt
Reference:
Nosyk B, Zang X, Krebs E, et al. Ending the HIV epidemic in the USA: an economic modelling study in six cities [Published online March 5, 2020]. Lancet HIV. doi:10.1016/S2352-3018(20)30033-3