Impact of Improved HIV Care and Treatment on PrEP Effectiveness in the United States, 2016-2020

Preferences for longer acting pre-exposure prophylaxis in transgender and gender expansive texans: centering gender affirming hormone therapy

The prevalence of HIV is higher in the transgender population than in the general population, and pre-exposure prophylaxis (PrEP) is an effective biomedical HIV prevention strategy for the prevention of HIV. However, the transgender and gender-expansive community faces several challenges to PrEP uptake and adherence. This community-based participatory study was conducted to understand preferences for long-acting PrEP modalities better. Data were collected virtually with an adapted version of the World Café Conversation method and in-depth interviews. A total of 33 transgender and gender-diverse individuals participated in either a World Café conversation or an individual interview about preferences for long-acting PrEP. All qualitative data were transcribed and coded for themes. Two themes emerged: (1) challenges related to long-acting PrEP for transgender and gender-expansive individuals and (2) bundling long-acting PrEP and gender-affirming hormone therapy. To improve access and adherence, HIV prevention needs to be included as part of gender-affirming hormone therapy to align with patients' health priorities.

Emergency Department Patients' Perspectives on Being Offered Human Immunodeficiency Virus Pre-Exposure Prophylaxis Services in an Urban Emergency Department

HIV pre-exposure prophylaxis (PrEP) is underutilized in the United States. Emergency departments (EDs) can be strategic locations for initiating PrEP; however, knowledge concerning patients' receptivity to ED PrEP programs is limited. This study explores ED patients' perspectives on PrEP service delivery and their preferences for implementation. Semi-structured qualitative interviews were conducted with 15 potentially PrEP-eligible ED patients to examine their receptiveness to PrEP services, preferences for delivery methods, and logistical considerations. Most participants were open to learning about PrEP in the ED, provided it did not delay care, occur during distress, or compromise privacy. Universal PrEP education was viewed as reducing stigma and increasing awareness, while targeted screening was considered efficient. Participants strongly preferred receiving information in person rather than via videos or pamphlets. Concerns included ensuring ED staff expertise and maintaining privacy during PrEP-related discussions. Opinions on initiating same-day PrEP versus prescriptions or referrals varied, with participants valuing flexibility and linkage to care. This first qualitative study of ED patients' perspectives on PrEP services highlights general receptiveness, with key concerns about privacy, expertise, and wait times. Patient-centered approaches, such as integrating services into ED workflows, offering flexible initiation options, and providing privacy, can address barriers and enhance the feasibility of ED-based PrEP programs.

Mechanistic modeling of social conditions in disease-prediction simulations via copulas and probabilistic graphical models: HIV case study

As social and economic conditions are key determinants of HIV, the United States 'National HIV/AIDS Strategy (NHAS)', in addition to care and treatment, aims to address mental health, unemployment, food insecurity, and housing instability, as part of its strategic plan for the 'Ending the HIV Epidemic' initiative. Although mechanistic models of HIV play a key role in evaluating intervention strategies, social conditions are typically not part of the modeling framework. Challenges include the unavailability of coherent statistical data for social conditions and behaviors. We developed a method, combining undirected graphical modeling with copula methods, to integrate disparate data sources, to estimate joint probability distributions for social conditions and behaviors. We incorporated these in a national-level network model, Progression and Transmission of HIV (PATH 4.0), to simulate behaviors as functions of social conditions and HIV transmissions as a function of behaviors. As a demonstration for the potential applications of such a model, we conducted two hypothetical what-if intervention analyses to estimate the impact of an ideal 100% efficacious intervention strategy. The first analysis modeled care behavior (using viral suppression as proxy) as a function of depression, neighborhood, housing, poverty, education, insurance, and employment status. The second modeled sexual behaviors (number of partners and condom-use) as functions of employment, housing, poverty, and education status, among persons who exchange sex. HIV transmissions and disease progression were then simulated as functions of behaviors to estimate incidence reductions. Social determinants are key drivers of many infectious and non-infectious diseases. Our work enables the development of decision support tools to holistically evaluate the syndemics of health and social inequity.

Emergency Department Patients' Perspectives on Being Offered HIV Pre-Exposure Prophylaxis (PrEP) Services in an Urban ED

HIV pre-exposure prophylaxis (PrEP) is underutilized in the United States. Emergency Departments (EDs) can be strategic locations for initiating PrEP; however, knowledge concerning patients' receptivity to ED PrEP programs is limited. This study explores ED patients' perspectives on PrEP service delivery and their preferences for implementation. Semi-structured qualitative interviews were conducted with 15 potentially PrEP-eligible ED patients to examine their receptiveness to PrEP services, preferences for delivery methods, and logistical considerations. Most participants were open to learning about PrEP in the ED, provided it did not delay care, occur during distress, or compromise privacy. Universal PrEP education was viewed as reducing stigma and increasing awareness, while targeted screening was seen as efficient. Participants strongly preferred receiving information in person rather than via videos or pamphlets. Concerns included ensuring ED staff expertise and maintaining privacy during PrEP-related discussions. Regarding same-day PrEP versus prescriptions or referrals, opinions varied, with participants valuing flexibility and linkage to care. This first qualitative study of ED patients' perspectives on PrEP services highlights general receptiveness, with key concerns about privacy, expertise, and wait times. Patient-centered approaches, including integrating PrEP services into ED workflows, offering flexible initiation options, and providing privacy, can support the feasibility of ED-based PrEP programs.

Knowledge and Attitude About Pre-exposure Prophylaxis Among Primary Care Clinicians at a Federally Qualified Health Center in Central Texas: A Cross-sectional Study

ABSTRACT

Pre-exposure prophylaxis (PrEP) for HIV prevention is a highly effective tool in preventing HIV, yet PrEP is underprescribed. Primary care providers are ideally positioned to increase access to and awareness of PrEP, but health care providers' knowledge of PrEP greatly varies. To evaluate PrEP knowledge and attitudes of primary care providers, we conducted a descriptive cross-sectional study examining primary providers' knowledge and concerns about PrEP. Participants ( n = 122) included physicians, nurses, pharmacists, and residency trainees in family medicine, internal medicine, and obstetrics. Despite high awareness of PrEP among these primary care providers (91.7%), fewer reported feeling comfortable prescribing PrEP (62.5%), and the average number of PrEP prescriptions per provider written in the last 6 months was less than 1. PrEP remains key to preventing HIV, but prescriptions remain low. Health care providers would benefit from additional education and training on communicating with their patients about sexual health and HIV prevention.

Trends in preexposure prophylaxis use among sex partners as reported by persons with HIV - United States, May 2015-June 2020

OBJECTIVE

To estimate trends in the proportion of sexually active U.S. adults with HIV (PWH) reporting an HIV-discordant sexual partner taking preexposure prophylaxis (PrEP) and proportion of partners taking PrEP.

DESIGN

The Medical Monitoring Project is a complex sample survey of U.S. adults with diagnosed HIV.

METHODS

We used annual cross-sectional data collected during June 2015-May 2020 to estimate the annual percentage change (EAPC), overall and by selected characteristics, in reported partner PrEP use among PWH with HIV-discordant partners (N = 8707) and reported PrEP use among these partners (N = 15 844).

RESULTS

The proportion of PWH reporting PrEP use by one or more HIV-discordant sex partner rose 19.5% annually (11.3 to 24.4%). The prevalence rose from 6.0 to 17.4% (EAPC, 25.8%) among Black PWH, 10.1 to 26.0% (EAPC, 19.5%) among Hispanic/Latino PWH, and 20.8 to 34.6% (EAPC, 16.3%) among White PWH. Among MSM with HIV, the prevalence increased from 9.6 to 32.6% (EAPC, 28.2%) among Black MSM, 16.6 to 36.0% (EAPC, 15.6%) among Hispanic/Latino MSM, and 24.9 to 44.1% (EAPC, 17.9%) among White MSM. Among HIV-discordant sex partners, the proportion reported to be taking PrEP increased 21.1% annually (7.8 to 18.8%). Reported PrEP use rose from 4.9 to 14.2% (EAPC, 29.9%) among Black partners, 6.5 to 16.8% (EAPC, 20.3%) among Hispanic/Latino partners, and 12.7 to 26.1% (EAPC, 17.0%) among White partners.

CONCLUSIONS

One in five HIV-discordant sexual partners of PWH was reported to be taking PrEP. PrEP use rose among all examined populations, although the increases did not eliminate disparities in PrEP use.

Evaluating the sensitivity of jurisdictional heterogeneity and jurisdictional mixing in national level HIV prevention analyses: context of the U.S. ending the HIV epidemic plan

BACKGROUND

The U.S. Ending the HIV epidemic (EHE) plan aims to reduce annual HIV incidence by 90% by 2030, by first focusing interventions on 57 regions (EHE jurisdictions) that contributed to more than 50% of annual HIV diagnoses. Mathematical models that project HIV incidence evaluate the impact of interventions and inform intervention decisions. However, current models are either national level, which do not consider jurisdictional heterogeneity, or independent jurisdiction-specific, which do not consider cross jurisdictional interactions. Data suggests that a significant proportion of persons have sexual partnerships outside their own jurisdiction. However, the sensitivity of these jurisdictional interactions on model outcomes and intervention decisions hasn't been studied.

METHODS

We developed an ordinary differential equations based compartmental model to generate national-level projections of HIV in the U.S., through dynamic simulations of 96 epidemiological sub-models representing 54 EHE and 42 non-EHE jurisdictions. A Bernoulli equation modeled HIV-transmissions using a mixing matrix to simulate sexual partnerships within and outside jurisdictions. To evaluate sensitivity of jurisdictional interactions on model outputs, we analyzed 16 scenarios, combinations of a) proportion of sexual partnerships mixing outside jurisdiction: no-mixing, low-level-mixing-within-state, high-level-mixing-within-state, or high-level-mixing-within-and-outside-state; b) jurisdictional heterogeneity in care and demographics: homogenous or heterogeneous; and c) intervention assumptions for 2019-2030: baseline or EHE-plan (diagnose, treat, and prevent).

RESULTS

Change in incidence in mixing compared to no-mixing scenarios varied by EHE and non-EHE jurisdictions and aggregation-level. When assuming jurisdictional heterogeneity and baseline-intervention, the change in aggregated incidence ranged from - 2 to 0% for EHE and 5 to 21% for non-EHE, but within each jurisdiction it ranged from - 31 to 46% for EHE and - 18 to 109% for non-EHE. Thus, incidence estimates were sensitive to jurisdictional mixing more at the jurisdictional level. As a result, jurisdiction-specific HIV-testing intervals inferred from the model to achieve the EHE-plan were also sensitive, e.g., when no-mixing scenarios suggested testing every 1 year (or 3 years), the three mixing-levels suggested testing every 0.8 to 1.2 years, 0.6 to 1.5 years, and 0.6 to 1.5 years, respectively (or 2.6 to 3.5 years, 2 to 4.8 years, and 2.2 to 4.1 years, respectively). Similar patterns were observed when assuming jurisdictional homogeneity, however, change in incidence in mixing compared to no-mixing scenarios were high even in aggregated incidence.

CONCLUSIONS

Accounting jurisdictional mixing and heterogeneity could improve model-based analyses.

Are Unequal Policies in Pre-Exposure Prophylaxis Uptake Needed to Improve Equality? An Examination Among Men Who Have Sex with Men in Los Angeles County

Racial and ethnic minority men who have sex with men (MSM) are disproportionately affected by HIV/AIDS in Los Angeles County (LAC), an important epicenter in the battle to end HIV. We examine tradeoffs between effectiveness and equality of pre-exposure prophylaxis (PrEP) allocation strategies among different racial and ethnic groups of MSM in LAC and provide a framework for quantitatively evaluating disparities in HIV outcomes. To do this, we developed a microsimulation model of HIV among MSM in LAC using county epidemic surveillance and survey data to capture demographic trends and subgroup-specific partnership patterns, disease progression, patterns of PrEP use, and patterns for viral suppression. We limit analysis to MSM, who bear most of the burden of HIV/AIDS in LAC. We simulated interventions where 3000, 6000, or 9000 PrEP prescriptions are provided annually in addition to current levels, following different allocation scenarios to each racial/ethnic group (Black, Hispanic, or White). We estimated cumulative infections averted and measures of equality, after 15 years (2021-2035), relative to base case (no intervention). By comparing allocation strategies on the health equality impact plane, we find that, of the policies evaluated, targeting PrEP preferentially to Black individuals would result in the largest reductions in incidence and disparities across the equality measures we considered. This result was consistent over a range of PrEP coverage levels, demonstrating that there are "win-win" PrEP allocation strategies that do not require a tradeoff between equality and efficiency.

Using Microsimulation Modeling to Inform EHE Implementation Strategies in Los Angeles County

BACKGROUND

Pre-exposure prophylaxis (PrEP) is essential to ending HIV. Yet, uptake remains uneven across racial and ethnic groups. We aimed to estimate the impacts of alternative PrEP implementation strategies in Los Angeles County.

SETTING

Men who have sex with men, residing in Los Angeles County.

METHODS

We developed a microsimulation model of HIV transmission, with inputs from key local stakeholders. With this model, we estimated the 15-year (2021-2035) health and racial and ethnic equity impacts of 3 PrEP implementation strategies involving coverage with 9000 additional PrEP units annually, above the Status-quo coverage level. Strategies included PrEP allocation equally (strategy 1), proportionally to HIV prevalence (strategy 2), and proportionally to HIV diagnosis rates (strategy 3), across racial and ethnic groups. We measured the degree of relative equalities in the distribution of the health impacts using the Gini index (G) which ranges from 0 (perfect equality, with all individuals across all groups receiving equal health benefits) to 1 (total inequality).

RESULTS

HIV prevalence was 21.3% in 2021 [Black (BMSM), 31.1%; Latino (LMSM), 18.3%, and White (WMSM), 20.7%] with relatively equal to reasonable distribution across groups (G, 0.28; 95% confidence interval [CI], 0.26 to 0.34). During 2021-2035, cumulative incident infections were highest under Status-quo (n = 24,584) and lowest under strategy 3 (n = 22,080). Status-quo infection risk declined over time among all groups but remained higher in 2035 for BMSM (incidence rate ratio, 4.76; 95% CI: 4.58 to 4.95), and LMSM (incidence rate ratio, 1.74; 95% CI: 1.69 to 1.80), with the health benefits equally to reasonably distributed across groups (G, 0.32; 95% CI: 0.28 to 0.35). Relative to Status-quo, all other strategies reduced BMSM-WMSM and BMSM-LMSM disparities, but none reduced LMSM-WMSM disparities by 2035. Compared to Status-quo, strategy 3 reduced the most both incident infections (% infections averted: overall, 10.2%; BMSM, 32.4%; LMSM, 3.8%; WMSM, 3.5%) and HIV racial inequalities (G reduction, 0.08; 95% CI: 0.02 to 0.14).

CONCLUSIONS

Microsimulation models developed with early, continuous stakeholder engagement and inputs yield powerful tools to guide policy implementation.

The Cost-Effectiveness of HIV/STI Prevention in High-Income Countries with Concentrated Epidemic Settings: A Scoping Review

The purpose of this scoping review is to establish the state of the art on economic evaluations in the field of HIV/STI prevention in high-income countries with concentrated epidemic settings and to assess what we know about the cost-effectiveness of different measures. We reviewed economic evaluations of HIV/STI prevention measures published in the Web of Science and Cost-Effectiveness Registry databases. We included a total of 157 studies focusing on structural, behavioural, and biomedical interventions, covering a variety of contexts, target populations and approaches. The majority of studies are based on mathematical modelling and demonstrate that the preventive measures under scrutiny are cost-effective. Interventions targeted at high-risk populations yield the most favourable results. The generalisability and transferability of the study results are limited due to the heterogeneity of the populations, settings and methods involved. Furthermore, the results depend heavily on modelling assumptions. Since evidence is unequally distributed, we discuss implications for future research.

Evidence and implication of interventions across various socioecological levels to address pre-exposure prophylaxis uptake and adherence among men who have sex with men in the United States: a systematic review

BACKGROUND

Pre-exposure prophylaxis (PrEP) represents a proven biomedical strategy to prevent HIV transmissions among men who have sex with men (MSM) in the United States (US). Despite the design and implementation of various PrEP-focus interventions in the US, aggregated evidence for enhancing PrEP uptake and adherence is lacking. The objective of this systematic review is to synthesize and evaluate interventions aimed to improve PrEP uptake and adherence among MSM in the US, and identify gaps with opportunities to inform the design and implementation of future PrEP interventions for these priority populations.

METHODS

We followed the PRISMA guidelines and conducted a systematic review of articles (published by November 28, 2021) with a focus on PrEP-related interventions by searching multiple databases (PubMed, MEDLINE, Web of Science and PsycINFO). Details of PrEP interventions were characterized based on their socioecological level(s), implementation modalities, and stage(s) of PrEP cascade continuum.

RESULTS

Among the 1363 articles retrieved from multiple databases, 42 interventions identified from 47 publications met the inclusion criteria for this review. Most individual-level interventions were delivered via text messages and/or apps and incorporated personalized elements to tailor the intervention content on participants' demographic characteristics or HIV risk behaviors. Interpersonal-level interventions often employed peer mentors or social network strategies to enhance PrEP adoption among MSM of minority race. However, few interventions were implemented at the community-, healthcare/institution- or multiple levels.

CONCLUSIONS

Interventions that incorporate multiple socioecological levels hold promise to facilitate PrEP adoption and adherence among MSM in the US given their acceptability, feasibility, efficacy and effectiveness. Future PrEP interventions that simultaneously address PrEP-related barriers/facilitators across multiple socioecological levels should be enhanced with a focus to tackle contextual and structural barriers (e.g., social determinants of health, stigma or medical mistrust) at the community- and healthcare/institution-level to effectively promote PrEP use for MSM of color.

Optimizing HIV Prevention Efforts to Achieve EHE Incidence Targets

BACKGROUND

A goal of the US Department of Health and Human Services' Ending the HIV Epidemic (EHE) in the United States initiative is to reduce the annual number of incident HIV infections in the United States by 75% within 5 years and by 90% within 10 years. We developed a resource allocation analysis to understand how these goals might be met.

METHODS

We estimated the current annual societal funding [$2.8 billion (B)/yr] for 14 interventions to prevent HIV and facilitate treatment of infected persons. These interventions included HIV testing for different transmission groups, HIV care continuum interventions, pre-exposure prophylaxis, and syringe services programs. We developed scenarios optimizing or reallocating this funding to minimize new infections, and we analyzed the impact of additional EHE funding over the period 2021-2030.

RESULTS

With constant current annual societal funding of $2.8 B/yr for 10 years starting in 2021, we estimated the annual incidence of 36,000 new cases in 2030. When we added annual EHE funding of $500 million (M)/yr for 2021-2022, $1.5 B/yr for 2023-2025, and $2.5 B/yr for 2026-2030, the annual incidence of infections decreased to 7600 cases (no optimization), 2900 cases (optimization beginning in 2026), and 2200 cases (optimization beginning in 2023) in 2030.

CONCLUSIONS

Even without optimization, significant increases in resources could lead to an 80% decrease in the annual HIV incidence in 10 years. However, to reach both EHE targets, optimization of prevention funding early in the EHE period is necessary. Implementing these efficient allocations would require flexibility of funding across agencies, which might be difficult to achieve.

The Influence of Family Bonding, Support, Engagement in Healthcare, on PrEP Stigma among Young Black and Latino Men Who Have Sex with Men: A Path Analysis

This study employs the ecodevelopmental theory to examine the influence of mother and father bonding, family engagement in healthcare, and family support on PrEP stigma among BLMSM. We used a cross-sectional sample from wave five of the Healthy Young Men (HYM) study, with a survey sample of 399 participants aged 16−24 years. We conducted two-path analyses to test multiple hypotheses: (1) mother/father bonding is associated with an increase in family engagement in healthcare; (2) family engagement in healthcare is associated with family social support; and (3) family social support is associated with PrEP stigma. Family social support was negatively correlated with PrEP stigma (r = −0.15; p < 0.001). The findings show that families either led by a Black/Latino father or mother have a significant impact on the sexual health-seeking behavior of BLMSM and their perception of HIV and PrEP.

Estimating the HIV Effective Reproduction Number in the United States and Evaluating HIV Elimination Strategies

CONTEXT

The reproduction number is a fundamental epidemiologic concept used to assess the potential spread of infectious diseases and whether they can be eliminated.

OBJECTIVE

We estimated the 2017 United States HIV effective reproduction number, Re, the average number of secondary infections from an infected person in a partially infected population. We analyzed the potential effects on Re of interventions aimed at improving patient flow rates along different stages of the HIV care continuum. We also examined these effects by individual transmission groups.

DESIGN

We used the HIV Optimization and Prevention Economics (HOPE) model, a compartmental model of disease progression and transmission, and the next-generation matrix method to estimate Re. We then projected the impact of changes in HIV continuum-of-care interventions on the continuum-of-care flow rates and the estimated Re in 2020.

SETTING

United States.

PARTICIPANTS

The HOPE model simulated the sexually active US population and persons who inject drugs, aged 13 to 64 years, which was stratified into 195 subpopulations by transmission group, sex, race/ethnicity, age, male circumcision status, and HIV risk level.

MAIN OUTCOME MEASURES

The estimated value of Re in 2017 and changes in Re in 2020 from interventions affecting the continuum-of-care flow rates.

RESULTS

Our estimated HIV Re in 2017 was 0.92 [0.82, 0.94] (base case [min, max across calibration sets]). Among the interventions considered, the most effective way to reduce Re substantially below 1.0 in 2020 was to maintain viral suppression among those receiving HIV treatment. The greatest impact on Re resulted from changing the flow rates for men who have sex with men (MSM).

CONCLUSIONS

Our results suggest that current prevention and treatment efforts may not be sufficient to move the country toward HIV elimination. Reducing Re to substantially below 1.0 may be achieved by an ongoing focus on early diagnosis, linkage to care, and sustained viral suppression especially for MSM.

Similar Sexual Behaviour yet Different Outcomes: Comparing Trans and Gender Diverse and Cis PrEP Users in Germany Based on the Outcomes of the PrApp Study

Little knowledge about pre-exposure prophylaxis (PrEP) use in trans and gender diverse (TGD) communities in Germany exists. The PrApp Study collected data on PrEP use and sexual behaviour among PrEP users in Germany. Descriptive methods and logistic regression were used to describe PrEP use among TGD and cis persons. A total of 4350 PrEP users in Germany were included, with 65 (1.5%) identified as TGD. Compared to cis participants, TGD participants were younger (median age 29 vs. 37 years) and more likely to have a lower income (adjusted odds ratio (aOR) = 4.4; 95% confidence interval (CI) = 2.4–8.2) and be born outside Germany (aOR = 2.5; 95% CI = 1.3–4.5). On-demand PrEP use was higher in TGD participants (aOR = 1.9; 95% CI = 1.0–3.5) and numerically more TGD obtained PrEP from informal sources (aOR = 1.8; 95% CI = 0.9–3.5). Testing behaviour, condom use, and number of sexual partners were comparable between both groups. Socioeconomic disparities may constitute structural barriers for TGD people to access PrEP, leading to more informal and on-demand use. PrEP providers need to reduce access barriers for TGD PrEP users and provide information on safe PrEP use for this population.

A reinforcement learning model to inform optimal decision paths for HIV elimination

The 'Ending the HIV Epidemic (EHE)' national plan aims to reduce annual HIV incidence in the United States from 38,000 in 2015 to 9300 by 2025 and 3300 by 2030. Diagnosis and treatment are two most effective interventions, and thus, identifying corresponding optimal combinations of testing and retention-in-care rates would help inform implementation of relevant programs. Considering the dynamic and stochastic complexity of the disease and the time dynamics of decision-making, solving for optimal combinations using commonly used methods of parametric optimization or exhaustive evaluation of pre-selected options are infeasible. Reinforcement learning (RL), an artificial intelligence method, is ideal; however, training RL algorithms and ensuring convergence to optimality are computationally challenging for large-scale stochastic problems. We evaluate its feasibility in the context of the EHE goal. We trained an RL algorithm to identify a 'sequence' of combinations of HIV-testing and retention-in-care rates at 5-year intervals over 2015-2070 that optimally leads towards HIV elimination. We defined optimality as a sequence that maximizes quality-adjusted-life-years lived and minimizes HIV-testing and care-and-treatment costs. We show that solving for testing and retention-in-care rates through appropriate reformulation using proxy decision-metrics overcomes the computational challenges of RL. We used a stochastic agent-based simulation to train the RL algorithm. As there is variability in support-programs needed to address barriers to care-access, we evaluated the sensitivity of optimal decisions to three cost-functions. The model suggests to scale-up retention-in-care programs to achieve and maintain high annual retention-rates while initiating with a high testing-frequency but relaxing it over a 10-year period as incidence decreases. Results were mainly robust to the uncertainty in costs. However, testing and retention-in-care alone did not achieve the 2030 EHE targets, suggesting the need for additional interventions. The results from the model demonstrated convergence. RL is suitable for evaluating phased public health decisions for infectious disease control.

Reaching Those Most at Risk for HIV Acquisition: Evaluating Racial/Ethnic Disparities in the Preexposure Prophylaxis Care Continuum in Baltimore City, Maryland

BACKGROUND

Reducing HIV incidence requires addressing persistent racial/ethnic disparities in HIV burden. Our goal was to evaluate preexposure prophylaxis (PrEP) delivery, overall and relative to community need, among 7 clinical sites participating in a health department-led demonstration project to increase PrEP in Baltimore city, MD.

METHODS

PrEP care continuum stages (screened, indicated, referred, linked, evaluated, prescribed) were examined among HIV-negative individuals receiving services at participating sites between September 30, 2015 and September 29, 2019. Community need was defined using information on new HIV diagnoses (2016-2018). Differences in care continuum progression by demographics/priority population and comparison of demographic compositions between care continuum stages and new HIV diagnoses were examined using modified Poisson regression and χ2 tests, respectively.

RESULTS

Among 25,886 PrEP-screened individuals, the majority were non-Hispanic (NH) black (81.1%, n = 20,998), cisgender male (61.1%, n = 15,825), and heterosexual (86.7%, n = 22,452). Overall, 31.1% (n = 8063) were PrEP-indicated; among whom, 56.8% (n = 4578), 15.6% (n = 1250), 10.8% (n = 868), and 9.0% (n = 722) were PrEP-referred, linked, evaluated, and prescribed, respectively. Among 2870 men who have sex with men (MSM), 18.7% (n = 538) were PrEP-prescribed. Across all groups, the highest attrition was between PrEP-referred and PrEP-linked. NH-black race (vs. NH-white) was independently associated with lower likelihood of PrEP prescription (aPR, 0.89; 95% confidence interval, 0.81 to 0.98 controlling for age/gender). Relative to the demographic composition of new HIV diagnoses, fewer NH-blacks (80.2% vs. 54.3%) and more NH-whites (10.7% vs. 30.3%) and MSM were PrEP prescribed (55.2% vs. 74.5%).

CONCLUSIONS

This project showed promise delivering PrEP referrals and prescriptions overall and to MSM. Substantial improvement is needed to improve linkage overall and to decrease disparities in PrEP prescriptions among NH-blacks. Future work should focus on addressing service gaps that hinder PrEP utilization.

Evidence of an Association of Increases in Pre-exposure Prophylaxis Coverage With Decreases in Human Immunodeficiency Virus Diagnosis Rates in the United States, 2012-2016

BACKGROUND

Annual human immunodeficiency virus (HIV) diagnoses in the United States (US) have plateaued since 2013. We assessed whether there is an association between uptake of pre-exposure prophylaxis (PrEP) and decreases in HIV diagnoses.

METHODS

We used 2012-2016 data from the US National HIV Surveillance System to estimate viral suppression (VS) and annual percentage change in diagnosis rate (EAPC) in 33 jurisdictions, and data from a national pharmacy database to estimate PrEP uptake. We used Poisson regression with random effects for state and year to estimate the association between PrEP coverage and EAPC: within jurisdictional quintiles grouped by changes in PrEP coverage, regressing EAPC on time; and among all jurisdictions, regressing EAPC on both time and jurisdictional changes in PrEP coverage with and without accounting for changes in VS.

RESULTS

From 2012 to 2016, across the 10 states with the greatest increases in PrEP coverage, the EAPC decreased 4.0% (95% confidence interval [CI], -5.2% to -2.9%). On average, across the states and District of Columbia, EAPC for a given year decreased by 1.1% (95% CI, -1.77% to -.49%) for an increase in PrEP coverage of 1 per 100 persons with indications. When controlling for VS, the state-specific EAPC for a given year decreased by 1.3% (95% CI, -2.12% to -.57%) for an increase in PrEP coverage of 1 per 100 persons with indications.

CONCLUSIONS

We found statistically significant associations between jurisdictional increases in PrEP coverage and decreases in EAPC independent of changes in VS, which supports bringing PrEP use to scale in the US to accelerate reductions in HIV infections.

Pre-exposure Prophylaxis Uptake and Discontinuation Among Young Black Men Who Have Sex With Men in Atlanta, Georgia: A Prospective Cohort Study

BACKGROUND

Human immunodeficiency virus (HIV) preexposure prophylaxis (PrEP) has great potential to reduce HIV incidence among young black men who have sex with men (YBMSM); however, initiation and persistence for this group remain low. We sought to understand the patterns and predictors of PrEP uptake and discontinuation among YBMSM in Atlanta, Georgia.

METHODS

PrEP was offered to all participants in a prospective cohort of YBMSM aged 18-29 years not living with HIV. Time to PrEP uptake, first discontinuation, and final discontinuation were assessed using the Kaplan-Meier method. Cox proportional hazard models were used to identify predictors of uptake and discontinuation.

RESULTS

After 440 person-years of follow-up, 44% of YBMSM initiated PrEP through the study after a median of 122 days. Of PrEP initiators, 69% had a first discontinuation and 40% had a final discontinuation during the study period. The median time to first PrEP discontinuation was 159 days. Factors associated with PrEP uptake included higher self-efficacy, sexually transmitted infection (STI), and condomless anal intercourse. Factors associated with discontinuation included younger age, cannabis use, STI, and fewer sex partners. HIV incidence was 5.23/100 person-years (95% confidence interval [CI], 3.40-7.23), with a lower rate among those who started PrEP (incidence rate ratio, 0.39; 95% CI, .16-.92).

CONCLUSIONS

Persistent PrEP coverage in this cohort of YBMSM was suboptimal, and discontinuations were common despite additional support services available through the study. Interventions to support PrEP uptake and persistence, especially for younger and substance-using YBMSM, are necessary to achieve full PrEP effectiveness.

CLINICAL TRIALS REGISTRATION

NCT02503618.

Progression and transmission of HIV (PATH 4.0)-A new agent-based evolving network simulation for modeling HIV transmission clusters

We present the Progression and Transmission of HIV (PATH 4.0), a simulation tool for analyses of cluster detection and intervention strategies. Molecular clusters are groups of HIV infections that are genetically similar, indicating rapid HIV transmission where HIV prevention resources are needed to improve health outcomes and prevent new infections. PATH 4.0 was constructed using a newly developed agent-based evolving network modeling (ABENM) technique and evolving contact network algorithm (ECNA) for generating scale-free networks. ABENM and ECNA were developed to facilitate simulation of transmission networks for low-prevalence diseases, such as HIV, which creates computational challenges for current network simulation techniques. Simulating transmission networks is essential for studying network dynamics, including clusters. We validated PATH 4.0 by comparing simulated projections of HIV diagnoses with estimates from the National HIV Surveillance System (NHSS) for 2010-2017. We also applied a cluster generation algorithm to PATH 4.0 to estimate cluster features, including the distribution of persons with diagnosed HIV infection by cluster status and size and the size distribution of clusters. Simulated features matched well with NHSS estimates, which used molecular methods to detect clusters among HIV nucleotide sequences of persons with HIV diagnosed during 2015-2017. Cluster detection and response is a component of the U.S. Ending the HIV Epidemic strategy. While surveillance is critical for detecting clusters, a model in conjunction with surveillance can allow us to refine cluster detection methods, understand factors associated with cluster growth, and assess interventions to inform effective response strategies. As surveillance data are only available for cases that are diagnosed and reported, a model is a critical tool to understand the true size of clusters and assess key questions, such as the relative contributions of clusters to onward transmissions. We believe PATH 4.0 is the first modeling tool available to assess cluster detection and response at the national-level and could help inform the national strategic plan.

Attitudes and Practices of a Sample of Nova Scotian Physicians for the Implementation of HIV Pre-Exposure Prophylaxis

Introduction

Pre-exposure prophylaxis (PrEP) is an effective HIV prevention tool that requires the ongoing support of physicians to be accessible. Recently, Nova Scotia experienced a 100% increase in HIV diagnoses. The purpose of this study is to explore the relationship between physicians' support of PrEP, knowledge of PrEP, and PrEP prescribing history using the information-motivation-behavioral (IMB) skills model.

Methods

An online survey was distributed to physicians in Nova Scotia, Canada, and eighty physicians participated. Two exploratory factor analyses were conducted with items from the Support of PrEP scale and Knowledge of PrEP scale. A mediation analysis was conducted to assess if knowledge of PrEP mediated the relationship between support of PrEP and whether physicians have prescribed PrEP in the past.

Results

On average, physicians reported strong support for PrEP, and as support for PrEP increased so did knowledge of PrEP. Further, physicians who had prescribed PrEP demonstrated strong knowledge of PrEP and physicians who had not prescribed PrEP reported feeling neutral. The 95% bootstrap confidence interval indirect effect of Support for PrEP on prescription history did not include zero (B = 1.59, 95% BsCI [0.83, 3.57]) demonstrating that the effect of support for PrEP is mediated by knowledge of PrEP. The most commonly identified barrier to prescribing PrEP was the lack of drug coverage among patients.

Conclusion

The results of the mediation analysis support the IMB skills model regarding support for PrEP, Knowledge of PrEP, and having prescribed PrEP in the past. Our findings suggest that to improve PrEP uptake in Nova Scotia, educational interventions for physicians and universal coverage of the drug would be necessary.

The last Black man with HIV in San Francisco: the potential role of gentrification on HIV getting to zero achievements

San Francisco was the first city in the USA to develop a Getting to Zero HIV elimination strategy. The cause of decreased HIV incidence has been attributed to the use of biomedical prevention methods, such as pre-exposure prophylaxis (PrEP) and treatment as prevention (TasP). These strategies have benefitted White men who have sex with men (MSM), whose population has increased over the past decade. However, Black MSM in San Francisco continue to have higher HIV incidence and outmigration rates. We posit that the declining overall HIV incidence, including among White MSM, is not only explained by the use of TaSP and PrEP, but is also due to the declining Black population and rising HIV incidence among Black MSM, who have historically been more likely to acquire HIV due to structural, racial, and criminal justice-related factors than have White MSM.

Optimal Allocation of Societal HIV Prevention Resources to Reduce HIV Incidence in the United States

Objectives. To optimize combined public and private spending on HIV prevention to achieve maximum reductions in incidence.Methods. We used a national HIV model to estimate new infections from 2018 to 2027 in the United States. We estimated current spending on HIV screening, interventions that move persons with diagnosed HIV along the HIV care continuum, pre-exposure prophylaxis, and syringe services programs. We compared the current funding allocation with 2 optimal scenarios: (1) a limited-reach scenario with expanded efforts to serve eligible persons and (2) an ideal, unlimited-reach scenario in which all eligible persons could be served.Results. A continuation of the current allocation projects 331 000 new HIV cases over the next 10 years. The limited-reach scenario reduces that number by 69%, and the unlimited reach scenario by 94%. The most efficient funding allocations resulted in prompt diagnosis and sustained viral suppression through improved screening of high-risk persons and treatment adherence support for those infected.Conclusions. Optimal allocations of public and private funds for HIV prevention can achieve substantial reductions in new infections. Achieving reductions of more than 90% under current funding will require that virtually all infected receive sustained treatment.

Treatment Is More Than Prevention: Perceived Personal and Social Benefits of Undetectable = Untransmittable Messaging Among Sexual Minority Men Living with HIV

Research suggests that the science of undetectable viral load (VL) status and HIV transmission-conveyed with the slogan "Undetectable = Untransmittable" or "U = U"-has gaps in acceptance despite robust scientific evidence. Nonetheless, growing acceptance of U = U creates conditions for a shift in the sociopolitical and personal implications of viral suppression. We conducted an online survey over a 23-month period in 2018 and 2019 among 30,361 adolescent and adult (aged 13-99) sexual minority men living with HIV (SMM-LHIV) across the United States. We examined the impact of U = U on self-image, potential for changing societal HIV stigma, whether SMM-LHIV had ever spoken with a provider about viral suppression and HIV transmission, and primary sources of hearing about U = U. Approximately 80% of SMM-LHIV reported that U = U was beneficial for their self-image and societal HIV stigma, 58.6% reported it made them feel "much better" about their own HIV status, and 40.6% reporting it had the potential to make HIV stigma "much better." The most consistent factors associated with these beliefs centered around care engagement, particularly self-reported viral suppression and excellent antiretroviral therapy adherence. Two-thirds reported ever talking to a provider about VL and HIV transmission, although the primary sources for having heard about U = U were HIV and lesbian, gay, bisexual, transgender, and queer (LGBTQ) news media and personal profiles on networking apps. These findings demonstrate the significant personal and social importance of U = U for SMM-LHIV that go above-and-beyond the well-documented health benefits of viral suppression, suggesting that providers should consider routinely initiating conversations with patients around the multifaceted benefits (personal health, sexual safety and intimacy, increased self-image, and reduced social stigma) of viral suppression.

A novel method to estimate the indirect community benefit of HIV interventions using a microsimulation model of HIV disease

BACKGROUND

Microsimulation models of human immunodeficiency virus (HIV) disease that simulate individual patients one at a time and assess clinical and economic outcomes of HIV interventions often provide key details regarding direct individual clinical benefits ("individual benefit"), but they may lack detail on transmissions, and thus may underestimate an intervention's indirect benefits ("community benefit"). Dynamic transmission models can be used to simulate HIV transmissions, but they may do so at the expense of the clinical detail of microsimulations. We sought to develop, validate, and demonstrate a practical, novel method that can be integrated into existing HIV microsimulation models to capture this community benefit, integrating the effects of reduced transmission while keeping the clinical detail of microsimulations.

METHODS

We developed a new method to capture the community benefit of HIV interventions by estimating HIV transmissions from the primary cohort of interest. The method captures the benefit of averting infections within the cohort of interest by estimating a corresponding gradual decline in incidence within the cohort. For infections averted outside the cohort of interest, our method estimates transmissions averted based on reductions in HIV viral load within the cohort, and the benefit (life-years gained and cost savings) of averting those infections based on the time they were averted. To assess the validity of our method, we paired it with the Cost-effectiveness of Preventing AIDS Complications (CEPAC) Model - a validated and widely-published microsimulation model of HIV disease. We then compared the consistency of model-estimated outcomes against outcomes of a widely-validated dynamic compartmental transmission model of HIV disease, the HIV Optimization and Prevention Economics (HOPE) model, using the intraclass correlation coefficient (ICC) with a two-way mixed effects model. Replicating an analysis done with HOPE, validation endpoints were number of HIV transmissions averted by offering pre-exposure prophylaxis (PrEP) to men who have sex with men (MSM) and people who inject drugs (PWID) in the US at various uptake and efficacy levels. Finally, we demonstrated an application of our method in a different setting by evaluating the clinical and economic outcomes of a PrEP program for MSM in India, a country currently considering PrEP rollout for this high-risk group.

RESULTS

The new method paired with CEPAC demonstrated excellent consistency with the HOPE model (ICC = 0.98 for MSM and 0.99 for PWID). With only the individual benefit of the intervention incorporated, a PrEP program for MSM in India averted 43,000 transmissions over a 5-year period and resulted in a lifetime incremental cost-effectiveness ratio (ICER) of US$2,300/year-of-life saved (YLS) compared to the status quo. After applying both the direct (individual) and indirect (community) benefits, PrEP averted 86,000 transmissions over the same period and resulted in an ICER of US$600/YLS.

CONCLUSIONS

Our method enables HIV microsimulation models that evaluate clinical and economic outcomes of HIV interventions to estimate the community benefit of these interventions (in terms of survival gains and cost savings) efficiently and without sacrificing clinical detail. This method addresses an important methodological gap in health economics microsimulation modeling and allows decision scientists to make more accurate policy recommendations.

A mathematical model to estimate the state-specific impact of the Health Resources and Services Administration's Ryan White HIV/AIDS Program

BACKGROUND

Access to and engagement in high-quality HIV medical care and treatment is essential for ending the HIV epidemic. The Health Resources and Services Administration's (HRSA) Ryan White HIV/AIDS Program (RWHAP) plays a critical role in ensuring that people living with diagnosed HIV (PLWH) are linked to and consistently engaged in high quality care and receive HIV medication in a timely manner. State variation in HIV prevalence, the proportion of PLWH served by the RWHAP, and local health care environments could influence the state-specific impact of the RWHAP. This analysis sought to measure the state-specific impact of the RWHAP on the HIV service delivery system and health outcomes for PLWH, and presents template language to communicate this impact for state planning and stakeholder engagement.

METHODS AND FINDINGS

The HRSA's HIV/AIDS Bureau (HAB) and the Centers for Disease Control and Prevention's Division of HIV/AIDS Prevention (CDC DHAP) have developed a mathematical model to estimate the state-specific impact of the RWHAP. This model was parameterized using RWHAP data, HIV surveillance data, an existing CDC model of HIV transmission and disease progression, and parameters from the literature. In this study, the model was used to analyze the hypothetical scenario of an absence of the RWHAP and to calculate the projected impact of this scenario on RWHAP clients, RWHAP-funded providers, mortality, new HIV cases, and costs compared with the current state inclusive of the RWHAP. To demonstrate the results of the model, we selected two states, representing high HIV prevalence and low HIV prevalence areas. These states serve to demonstrate the functionality of the model and how state-specific results can be translated into a state-specific impact statement using template language.

CONCLUSIONS

In the example states presented, the RWHAP provides HIV care, treatment, and support services to a large proportion of PLWH in each state. The absence of the RWHAP in these states could result in substantially more deaths and HIV cases than currently observed, resulting in considerable lifetime HIV care and treatment costs associated with additional HIV cases. State-specific impact statements may be valuable in the development of state-level HIV prevention and care plans or for communications with planning bodies, state health department leadership, and other stakeholders. State-specific impact statements will be available to RWHAP Part B recipients upon request from HRSA's HIV/AIDS Bureau.

Reported preexposure prophylaxis use among male sex partners of HIV-positive men: 2016-2018

OBJECTIVE

To estimate the proportion of US HIV-positive men who report a male HIV-negative/unknown status (HIV-discordant) sexual partner taking preexposure prophylaxis (PrEP), and the use of multiple HIV prevention strategies within partnerships.

DESIGN

The Medical Monitoring Project is a complex sample survey of US adults with diagnosed HIV.

METHODS

We used data collected during June 2016 to May 2018 among sexually active HIV-positive men who had at least one HIV-discordant male partner (N = 1871) to estimate the weighted prevalence of reporting at least one partner taking PrEP. Among HIV-discordant partnerships (N = 4029), we estimated PrEP use, viral suppression among HIV-positive partners, and condomless anal sex. We evaluated significant (P < 0.05) differences between groups using prevalence ratios with predicted marginal means.

RESULTS

Twenty-eight percent of sexually active HIV-positive MSM reported at least one HIV-discordant male partner taking PrEP. Twenty percent of HIV-discordant partners were reported to be taking PrEP; 73% were taking PrEP or the HIV-positive partner was virally suppressed. PrEP use was lower among black and Hispanic partners compared with white partners (12% and 19% vs. 27%). Fewer black than white MSM were in partnerships in which PrEP was used or the HIV-positive partner had sustained viral suppression (69% vs. 77%). Condomless anal intercourse was more prevalent in partnerships involving PrEP use and in partnerships involving either PrEP use or sustained viral suppression among the HIV-positive partner.

CONCLUSION

PrEP use was reported among one in five partners, with disparities between black and white partners. Increasing PrEP use and decreasing racial/ethnic disparities could reduce disparities in HIV incidence and help end the US HIV epidemic.

A modeling framework to inform preexposure prophylaxis initiation and retention scale-up in the context of 'Getting to Zero' initiatives

OBJECTIVE(S)

'Getting to Zero' (GTZ) initiatives aim to eliminate new HIV infections over a projected time frame. Increased preexposure prophylaxis (PrEP) uptake among populations with the highest HIV incidence, such as young Black MSM, is necessary to accomplish this aim. Agent-based network models (ABNMs) can help guide policymakers on strategies to increase PrEP uptake.

DESIGN

Effective PrEP implementation requires a model that incorporates the dynamics of interventions and dynamic feedbacks across multiple levels including virus, host, behavior, networks, and population. ABNMs are a powerful tool to incorporate these processes.

METHODS

An ABNM, designed for and parameterized using data for young Black MSM in Illinois, was used to compare the impact of PrEP initiation and retention interventions on HIV incidence after 10 years, consistent with GTZ timelines. Initiation interventions selected individuals in serodiscordant partnerships, or in critical sexual network positions, and compared with a controlled setting where PrEP initiators were randomly selected. Retention interventions increased the mean duration of PrEP use. A combination intervention modeled concurrent increases in PrEP initiation and retention.

RESULTS

Selecting HIV-negative individuals for PrEP initiation in serodiscordant partnerships resulted in the largest HIV incidence declines, relative to other interventions. For a given PrEP uptake level, distributing effort between increasing PrEP initiation and retention in combination was approximately as effective as increasing only one exclusively.

CONCLUSION

Simulation results indicate that expanded PrEP interventions alone may not accomplish GTZ goals within a decade, and integrated scale-up of PrEP, antiretroviral therapy, and other interventions might be necessary.