Disseminated Effects in Agent Based Models: A Potential Outcomes Framework and Application to Inform Pre-Exposure Prophylaxis Coverage Levels for HIV Prevention

Pre-exposure prophylaxis (PrEP) for HIV prevention may not only benefit the individual who uses it, but also their uninfected sexual risk contacts. We developed an agent-based model using a novel trial emulation approach to quantify disseminated effects of PrEP use among men who have sex with men in Atlanta, USA from 2015 to 2017. Components (subsets of agents connected through partnerships in a sexual network, but not sharing partnerships with any other agents) were first randomized to an intervention coverage level or control, then within intervention components, eligible agents were randomized to PrEP. We estimated direct and disseminated (indirect) effects using randomization-based estimators and reported corresponding 95% simulation intervals across scenarios ranging from 10% to 90% coverage in the intervention components. A population of 11,245 agents was simulated with an average of 1,551 components identified. Comparing agents randomized to PrEP in 70% coverage components to control agents, there was a 15% disseminated risk reduction in HIV incidence (95% simulation intervals = 0.65, 1.05). Individuals not on PrEP may receive a protective benefit by being in a sexual network with higher PrEP coverage. Agent-based models are useful to evaluate possible direct and disseminated effects of HIV prevention modalities in sexual networks

Projected effects of disruptions to human immunodeficiency virus (HIV) prevention services during the coronavirus disease 2019 pandemic among Black/African American men who have sex with men in an Ending the HIV Epidemic priority jurisdiction

BACKGROUND: Disruptions in access to in-person human immunodeficiency virus (HIV) preventive care during the coronavirus disease 2019 (COVID-19) pandemic may have a negative impact on our progress towards the Ending the HIV Epidemic goals in the United States. METHODS: We used an agent-based model to simulate HIV transmission among Black/African American men who have sex with men in Mississippi over 5 years to estimate how different reductions in access affected the number of undiagnosed HIV cases, new pre-exposure prophylaxis (PrEP) starts, and HIV incidence. RESULTS: We found that each additional 25% decrease in HIV testing and PrEP initiation was associated with decrease of 20% in the number of cases diagnosed and 23% in the number of new PrEP starts, leading to a 15% increase in HIV incidence from 2020 to 2022. CONCLUSIONS: Unmet need for HIV testing and PrEP prescriptions during the COVID-19 pandemic may temporarily increase HIV incidence in the years immediately after the disruption period

Defining a recovery-oriented cascade of care for opioid use disorder: A community-driven, statewide cross-sectional assessment

Background In light of the accelerating and rapidly evolving overdose crisis in the United States (US), new strategies are needed to address the epidemic and to efficiently engage and retain individuals in care for opioid use disorder (OUD). Moreover, there is an increasing need for novel approaches to using health data to identify gaps in the cascade of care for persons with OUD. Methods and findings Between June 2018 and May 2019, we engaged a diverse stakeholder group (including directors of statewide health and social service agencies) to develop a statewide, patient-centered cascade of care for OUD for Rhode Island, a small state in New England, a region highly impacted by the opioid crisis. Through an iterative process, we modified the cascade of care defined by Williams et al. for use in Rhode Island using key national survey data and statewide health claims datasets to create a cross-sectional summary of 5 stages in the cascade. Approximately 47,000 Rhode Islanders (5.2%) were estimated to be at risk for OUD (stage 0) in 2016. At the same time, 26,000 Rhode Islanders had a medical claim related to an OUD diagnosis, accounting for 55% of the population at risk (stage 1); 27% of the stage 0 population, 12,700 people, showed evidence of initiation of medication for OUD (MOUD, stage 2), and 18%, or 8,300 people, had evidence of retention on MOUD (stage 3). Imputation from a national survey estimated that 4,200 Rhode Islanders were in recovery from OUD as of 2016, representing 9% of the total population at risk. Limitations included use of self-report data to arrive at estimates of the number of individuals at risk for OUD and using a national estimate to identify the number of individuals in recovery due to a lack of available state data sources. Conclusions Our findings indicate that cross-sectional summaries of the cascade of care for OUD can be used as a health policy tool to identify gaps in care, inform data-driven policy decisions, set benchmarks for quality, and improve health outcomes for persons with OUD. There exists a significant opportunity to increase engagement prior to the initiation of OUD treatment (i.e., identification of OUD symptoms via routine screening or acute presentation) and improve retention and remission from OUD symptoms through improved community-supported processes of recovery. To do this more precisely, states should work to systematically collect data to populate their own cascade of care as a health policy tool to enhance system-level interventions and maximize engagement in care

Approaches to Sampling Gay, Bisexual, and Other Men Who Have Sex with Men from Geosocial-Networking Smartphone Applications: A Methodological Note

Geosocial-networking smartphone applications utilize global positioning system (GPS) technologies to connect users based on their physical proximity. Many gay, bisexual, and other men who have sex with men (MSM) have smartphones, and these new mobile technologies have generated quicker and easier modes for MSM to meet potential partners. In doing so, these technologies may facilitate a user’s ability to have multiple concurrent partners, thereby increasing their risk for acquiring HIV or other sexually transmitted infections. Researchers have sought to recruit users of these applications (e.g., Grindr, Jack’d, Scruff) into HIV prevention studies, primarily through advertising on the application. Given that these advertisements often broadly targeted large urban areas, these approaches have generated samples that are not representative of the population of users of the given application in a given area. As such, we propose a method to generate a spatially representative sample of MSM via direct messaging on a given application using New York City and its geography as an example of this sampling and recruitment method. These methods can increase geographic representativeness and wider access to MSM who use geosocial-networking smartphone applications

Acceptability of smartphone text- and voice-based ecological momentary assessment (EMA) methods among low income housing residents in New York City

Abstract Objectives This study aimed to evaluate the acceptability of smartphone-based text message- and voice-based ecological momentary assessment (EMA) methods among a sample of low-income housing residents in New York City. Using data from the community-based NYC Low Income Housing, Neighborhoods and Health Study (n = 112), the acceptability of text message- and voice-based EMA methods were assessed via survey. Results Overall, 88.4% of participants reported that they would participate in a study that utilized text message-based EMA. These analyses showed no appreciable differences by sub-groups (p > .05). Overall, 80.2% of participants reported that they would participate in a study that used voice-based EMA. This voice-based method was least acceptable among participants younger than 25 years old compared to participants of all other ages, χ2(2) = 10.107, p = .006 (among the younger participants 60.7% reported “yes” regarding the anticipated acceptability of voice-based EMA and 39.3% reported “no”). Overall, this work suggests that text message- and voice-based EMA methods are acceptable for use among low-income housing residents. However, the association between age and the acceptability of voice-based EMA suggests that these methods may be less suited for younger populations

Considerable interest in pre-exposure prophylaxis uptake among men who have sex with men recruited from a popular geosocial-networking smartphone application in London

Men who have sex with men (MSM) who use smartphone applications (apps) to meet sexual partners represent a high-risk subset of MSM. As such, the use of pre-exposure prophylaxis (PrEP) may be highly suitable. The purpose of the study was to evaluate awareness of and willingness to use PrEP among 179 HIV-uninfected MSM recruited in London who use these apps. Regression models were fit to assess the associations between perceived barriers and willingness to use PrEP in the future. Most (84.9%) had heard of PrEP and more than half (57.1%) were willing to use PrEP in the future if it were to become available. Low perceived risk for acquiring HIV (prevalence ratio (PR): 0.11; 95% confidence interval (CI): 0.04, 0.33) and concerns about PrEP-related side effects (PR: 0.01; 95% CI: 0.00, 0.04) were associated with being unwilling to use PrEP. Efforts to make PrEP widely available should be continued. Uptake interventions should focus on correcting self-perceptions of HIV risk and educate MSM about the potential side effects of PrEP use so that MSM can make more informed decisions about prevention options

Community-level norms and condomless anal intercourse among gay, bisexual, and other men who have sex with men who use geosocial-networking smartphone applications in the Deep South

Geosocial-networking smartphone applications represent an increasingly common virtual context in which men who have sex with men (MSM) meet their sexual partners. The purpose of the present study is to evaluate community-level sexual behavior norms and their associations with condom use among MSM in Atlanta, Georgia, recruited from a popular smartphone application (n = 92). Engagement in condomless anal intercourse was more common among participants who agreed that, among MSM in their community, (a) it is difficult to negotiate condom use in partnerships where condomless sex has already occurred and (b) suggesting condom use implies one distrusts their partner. These norms may represent barriers to increasing condom use