The dynamic relationship between social norms and behaviors: the results of an HIV prevention network intervention for injection drug users

Behavioral Modeling and its Association with PrEP and ART Use in Ugandan HIV-Serodifferent Couples

Integrating Pre-Exposure Prophylaxis (PrEP) delivery into Antiretroviral Therapy (ART) programs bridges the Human Immunodeficiency Virus (HIV) prevention gap for HIV-serodifferent couples prior to the partner living with HIV achieving viral suppression. Behavioral modeling is one mechanism that could explain health-related behavior among couples, including those using antiretroviral medications, but few tools exist to measure the extent to which behavior is modeled. Using a longitudinal observational design nested within a cluster randomized trial, this study examined the factor structure and assessed the internal consistency of a novel 24-item, four-point Likert-type scale to measure behavioral modeling and the association of behavioral modeling with medication-taking behaviors among heterosexual, cis-gender HIV-serodifferent couples. In 149 couples enrolled for research, a five-factor model provided the best statistical and conceptual fit, including attention to partner behavior, collective action, role modeling, motivation, and relationship quality. Behavioral modeling was associated with medication-taking behaviors among members of serodifferent couples. Partner modeling of ART/PrEP taking could be an important target for assessment and intervention in HIV prevention programs for HIV serodifferent couples.

Overall, Direct, Spillover, and Composite Effects of Components of a Peer-Driven Intervention Package on Injection Risk Behavior Among People Who Inject Drugs in the HPTN 037 Study

We sought to disentangle effects of the components of a peer-education intervention on self-reported injection risk behaviors among people who inject drugs (n = 560) in Philadelphia, US. We examined 226 egocentric groups/networks randomized to receive (or not) the intervention. Peer-education training consisted of two components delivered to the intervention network index individual only: (1) an initial training and (2) "booster" training sessions during 6- and 12-month follow up visits. In this secondary data analysis, using inverse-probability-weighted log-binomial mixed effects models, we estimated the effects of the components of the network-level peer-education intervention upon subsequent risk behaviors. This included contrasting outcome rates if a participant is a network member [non-index] under the network exposure versus under the network control condition (i.e., spillover effects). We found that compared to control networks, among intervention networks, the overall rates of injection risk behaviors were lower in both those recently exposed (i.e., at the prior visit) to a booster (rate ratio [95% confidence interval]: 0.61 [0.46-0.82]) and those not recently exposed to it (0.81 [0.67-0.98]). Only the boosters had statistically significant spillover effects (e.g., 0.59 [0.41-0.86] for recent exposure). Thus, both intervention components reduced injection risk behaviors with evidence of spillover effects for the boosters. Spillover should be assessed for an intervention that has an observable behavioral measure. Efforts to fully understand the impact of peer education should include routine evaluation of spillover effects. To maximize impact, boosters can be provided along with strategies to recruit especially committed peer educators and to increase attendance at trainings. Clinical Trials Registration Clinicaltrials.gov NCT00038688 June 5, 2002.

A mixed methods exploration of injection drug use risk behaviors and place-based norms in Ukraine

INTRODUCTION

Despite global reductions in HIV incidence and significant investment in local harm reduction services, Ukraine continues to experience high HIV and HCV prevalence among people who inject drugs (PWID). Place-based factors and social norms affect drug use-related risk factors, but research has paid little attention to the relationship between drug use practices and place in Ukraine, including how these factors may contribute to or protect against HIV/HCV risk.

METHODS

This project used a sequential mixed methods design. Between March and August 2018, we interviewed 30 PWID in Dnipro, Ukraine. Participants completed a single in-depth interview in which they described where and with whom they lived; how they generated income; and where, when, how, and with whom they purchased and used drugs. Between May 2019 and March 2020, we recruited 150 PWID in Dnipro to complete a survey that was designed based on interview findings and consisted of three components: an activity space inventory, an egocentric social network inventory, and an HIV risk behavior assessment.

RESULTS

Both interview and survey respondents reported consistent use of pharmacies to acquire syringes and nearly universal use of new syringes when injecting. Interview participants reflected that while syringe sharing was previously considered a "common practice," PWID now viewed it as infrequent and unacceptable. However, interview respondents enumerated the contexts in which needle and syringe reuse occurred, including purchasing drugs directly from a dealer and chipping in with other PWID to prepare drugs bought through a stash.

CONCLUSION

Participants described relatively easy access to new needles and syringes through pharmacies and expressed strong social sanctioning against reusing needles or syringes. However, equipment sharing behaviors and norms persisted in certain contexts, creating an opportunity for further harm reduction campaigns that incorporate changing norms in these situations to "close the gap" and further reduce HIV and other infections among PWID.

Effects of Online Friendships on Safer Sex Communication and Behavior among Black Sexual Minority Men: A Study of Network Exposure

This study draws on social normative and social learning theories to examine the masspersonal safer sex communication (i.e., Facebook posts about safer sex) and safer sex behavior (i.e., condom use) in a cohort of Black sexual minority men (BSMM) (N = 340), with an eye toward understanding their relationship with the safer sex communication and behaviors of their BSMM Facebook friends. Using linear network autocorrelation regression models, results showed that BSMM's safer sex communication and condom use behavior were each associated with the communication and behavior of their online peers. Specifically, BSMM's condom use was positively associated with their friends' condom use and friends' safer sex communication, and BSMMs' safer sex communication was positively associated with friends' safer sex communication. Moreover, contrary to prior research, BSSM's safer sex communication and condom use were not related to one another, suggesting that talking about safer sex on social media should not be interpreted to be an indication of engageDment in safer sex behavior. These findings underscore an opportunity to leverage peer influence in social media networks, particularly in the form of masspersonal communication, to encourage cascades of safer sex messaging among peers and adoption of safer sex behavior.

Social Networks, Stigma, and Hepatitis C Care Among Women Who Inject Drugs: Findings from A Community Recruited Sample

This study explores the role of perceived HCV stigma and social networks on HCV care among people who inject drugs (PWID) of both sexes, and solely among women who inject drugs (WWID). Data were from 269 HCV positive PWID, community-recruited through street-based outreach in Baltimore, MD. We defined HCV stigma based on participants' perceptions of treatment by others and their need to conceal their HCV status. Among WWID, HCV stigma was linked with decreased odds of undergoing liver disease staging (aOR = 0.33, 95% CI: 0.13,0.85) or to have attempted to get the HCV cure (aOR = 0.39, CI: 0.16,0.97), these associations were not evident in the overall sample with both sexes. Social network characteristics were significant correlates of HCV care in the overall sample, and these associations were stronger among WWID. WWID with more HCV positive social network members had higher odds of an HCV-related healthcare visit in the prior 12 months (aOR = 4.28, CI: 1.29,14.17) and to have undergone liver disease staging (aOR = 2.85, CI: 1.01,8.05). WWID with more social network members aware of the HCV cure were more likely to report an attempt at obtaining the HCV cure (aOR = 5.25, CI: 1.85,14.89). Our results suggest complexity in the role of social networks and stigma on HCV care.

The Impact of Social Media on Preventive Behavior During the COVID-19 Outbreak in South Korea: The Roles of Social Norms and Self-Efficacy

Social media are important channels to propagate health information and influence preventive behavior during a public health crisis, as witnessed during the coronavirus pandemic (COVID-19). This study explored the association between social media use and preventive behavior during the outbreak of COVID-19 in South Korea. Using the national survey data (N = 1,500), the study examined the mediating role of social norms in the association between social media use for news and information about COVID-19 and preventive behavior. In addition, the study tested the moderating effect of self-efficacy on the mediating path of social media use for preventive behavior via social norms. Conducting a moderated mediation analysis method, this study found that social norms mediated the relationship between social media use and preventive behavior (b = 0.046). Moreover, the study revealed that the indirect relationship between social media use and preventive behavior through social norms becomes stronger as an individual's level of self-efficacy decreases (low: b = 0.044, middle: b = 0.036, and high: b = 0.030). The study provides empirical evidence of the beneficial impact of social media use on preventive behavior. The findings of the study recommend promoting messages on social norms through social media for facilitating preventive behavior.

Marcotte A, M. Kaufman E, Moscovici Z, R. Adams O, Lovins S, R. Garcia J, N. Gesselman A. American Singles' Attitudes Toward Future Romantic/Sexual Partners' COVID-19 Vaccination Status: Evidence for both Vigilance and Indifference in a National Sample

Around 142 million American adults are currently single; at least half of these singles want to pursue a romantic partner. Romantic dating can involve exposure to numerous people. Thus, dating can significantly impact pathogen exposure risk. In a demographically-representative cross-sectional survey conducted in 2021 (N = 5,000), we examined U.S. American singles' COVID-19 vaccination status, assessed their preferences around a potential partner's COVID-19 vaccination status, and identified demographic subgroups of singles particularly opposed to or indifferent to a partner being vaccinated against COVID-19. Our results showed 65% of participants were fully vaccinated, 10% were partially vaccinated, and 26% were unvaccinated against COVID-19. With regards to partner preferences, half wanted a vaccinated partner; 18.9% wanted a vaccinated partner but would make exceptions; 6.1% wanted an unvaccinated partner; and 25% reported that they did not care about their dating partner's vaccination status. Partner preferences were largely aligned with participants' own vaccination status, such that vaccinated participants preferred vaccinated partners. However, those preferring unvaccinated partners-or those willing to make exceptions for a partner-were most likely to identify as men, younger in age, a political affiliation outside of the two-party political system, a gender or sexual minority, or as a racial minority (i.e., Black/African-American or South Asian). Additionally, participants who were employed (vs. unemployed) were more likely to make exceptions for or prefer an unvaccinated partner. These results suggest that singles prefer homophily in COVID-19 vaccine status, and that minoritized subgroups of singles are more likely to maintain a social network including unvaccinated close others.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12119-023-10097-9.

Factors influencing adolescent experimental and current smoking behaviors based on social cognitive theory: A cross-sectional study in Xiamen

Introduction

China has the largest youth population in the world. To better implement the Smoke-free School Initiative, this study aims to examine the protective and risk factors for different smoking behaviors (never smoked, experimental smoking, and current smoking) among school adolescents based on social cognitive theory.

Methods

This research was a secondary analysis of a cross-sectional survey of middle schools in Huli District of Xiamen, China. The final sample consisted of 1937 participants with an average age of 15.41 (SD = 1.64). Descriptive statistics were used to summarize the sociodemographic characteristics of the sample. Multivariate multinomial logistic regression analysis was performed using four models.

Results

Of the respondents, 1685 (86.99%) were never smokers, 210 (10.84%) were experimental smokers, and 42 (2.17%) were current smokers. Social norms, positive outcome expectations, anti-smoking self-efficacy, and attitudes toward control tobacco policies were associated with adolescents' smoking behaviors. The number of smoking family members, classmates smoking, the perception that smoking is cool and attractive, and attitudes toward control tobacco policies were the predictors of current smoking behavior (p < 0.05). In contrast, friends smoking and individual and social relationship motivation were associated with only experimental smoking (p < 0.05).

Discussion

The relationship of social norms, positive outcome expectations, anti-smoking self-efficacy, and attitudes toward control tobacco policies varied across smoking behaviors. Family, school, society and the government need to cooperate in prevention and intervention programs for adolescent smoking. The relationships between these factors and adolescents' different smoking behaviors needs to be further verified.

Methods for Assessing Spillover in Network-Based Studies of HIV/AIDS Prevention among People Who Use Drugs

Human Immunodeficiency Virus (HIV) interventions among people who use drugs (PWUD) often have spillover, also known as interference or dissemination, which occurs when one participant's exposure affects another participant's outcome. PWUD are often members of networks defined by social, sexual, and drug-use partnerships and their receipt of interventions can affect other members in their network. For example, HIV interventions with possible spillover include educational training about HIV risk reduction, pre-exposure prophylaxis, or treatment as prevention. In turn, intervention effects frequently depend on the network structure, and intervention coverage levels and spillover can occur even if not measured in a study, possibly resulting in an underestimation of intervention effects. Recent methodological approaches were developed to assess spillover in the context of network-based studies. This tutorial provides an overview of different study designs for network-based studies and related methodological approaches for assessing spillover in each design. We also provide an overview of other important methodological issues in network studies, including causal influence in networks and missing data. Finally, we highlight applications of different designs and methods from studies of PWUD and conclude with an illustrative example from the Transmission Reduction Intervention Project (TRIP) in Athens, Greece.

Evaluating the Mediating Role of Recall of Intervention Knowledge in the Relationship Between a Peer-Driven Intervention and HIV Risk Behaviors Among People Who Inject Drugs

Peer-driven interventions can be effective in reducing HIV injection risk behaviors among people who inject drugs (PWID). We employed a causal mediation framework to examine the mediating role of recall of intervention knowledge in the relationship between a peer-driven intervention and subsequent self-reported HIV injection-related risk behavior among PWID in the HIV Prevention Trials Network (HPTN) 037 study. For each intervention network, the index participant received training at baseline to become a peer educator, while non-index participants and all participants in the control networks received only HIV testing and counseling; recall of intervention knowledge was measured at the 6-month visit for each participant, and each participant was followed to ascertain HIV injection-related risk behaviors at the 12-month visit. We used inverse probability weighting to fit marginal structural models to estimate the total effect (TE) and controlled direct effect (CDE) of the intervention on the outcome. The proportion eliminated (PE) by intervening to remove mediation by the recall of intervention knowledge was computed. There were 385 participants (47% in intervention networks) included in the analysis. The TE and CDE risk ratios for the intervention were 0.47 [95% confidence interval (CI): 0.28, 0.78] and 0.73 (95% CI: 0.26, 2.06) and the PE was 49%. Compared to participants in the control networks, the peer-driven intervention reduced the risk of HIV injection-related risk behavior by 53%. The mediating role of recall of intervention knowledge accounted for less than 50% of the total effect of the intervention, suggesting that other potential causal pathways between the intervention and the outcome, such as motivation and skill, self-efficacy, social norms and behavior modeling, should be considered in future studies.

Network-level HIV risk norms are associated with individual-level HIV risk and harm reduction behaviors among people who inject drugs: a latent profile analysis

The COVID-19 related U.S.-Mexico border-crossing restrictions disrupted social networks and HIV harm reduction services among people who inject drugs (PWID) in San Diego and Tijuana. We assessed associations of descriptive network norms on PWID's HIV vulnerability during this period. Between 10/2020 and 10/2021, 399 PWID completed a behavioral and egocentric questionnaire. We used Latent Profile Analysis to categorize PWID into network norm risk profiles based on proportions of their network (n = 924 drug use alters) who injected drugs and engaged in cross-border drug use (CBDU), among other vulnerabilities. We used logistic and linear regressions to assess network profile associations with individual-level index of HIV vulnerability and harm reduction behaviors. Fit indices specified a 4-latent profile solution of descriptive network risk norms: lower (n = 178), moderate with (n = 34) and without (n = 94) CBDU and obtainment, and higher (n = 93). Participants in higher risk profiles reported more HIV vulnerability behaviors and fewer harm reduction behaviors. PWID's gradient of HIV risk was associated with network norms, warranting intervention on high-vulnerability networks when services are limited.

How Does Migration Affect HIV Sexual Risk Behaviors Among Involuntary Bachelors? The Mediating Roles of Neighborhoods and Social Networks

The sex ratio imbalance in China since the 1980s has resulted in a large number of involuntary bachelors in rural China. Previous studies have found an association between migration and HIV sexual risk behaviors among involuntary bachelors, but how migration affects these bachelors' HIV sexual risk behaviors remain poorly understood. Using data from a cross-sectional survey in 2017 (a sample of 740 male respondents who had rural household registration, had never been married, and were aged 28-49 years), we investigated the relationship between migration and HIV sexual risk behaviors. Logistic regressions show that migration, neighborhood characteristics, and social networks were significantly associated with commercial sex and multiple sex partners, whereas only neighborhood characteristics and social networks were positively correlated with sexual partnership concurrency. Neighborhood characteristics and social networks mediated the relationships of migration with commercial sex and migration with multiple sex partners. Social networks mediated the association between neighborhood characteristics and concurrency. Multiple-step mediation analysis showed that the indirect effect of migration on commercial sex and multiple sexual partners through neighborhood characteristics and social networks was significant. Our findings suggest that further interventions should address neighborhood characteristics and social networks together.

Social network and HIV/AIDS: A bibliometric analysis of global literature

Social networks (SN) shape HIV risk behaviors and transmission. This study was performed to quantify research development, patterns, and trends in the use of SN in the field of HIV/AIDS, and used Global publications extracted from the Web of Science Core Collection database. Networks of countries, research disciplines, and most frequently used terms were visualized. The Latent Dirichlet Allocation method was used for topic modeling. A linear regression model was utilized to identify the trend of research development. During the period 1991-2019, in a total of 5,698 publications, topics with the highest volume of publications consisted of (1) mental disorders (16.1%); (2) HIV/sexually transmitted infections prevalence in key populations (9.9%); and (3) HIV-related stigma (9.3%). Discrepancies in the geographical distribution of publications were also observed. This study highlighted (1) the rapid growth of publications on a wide range of topics regarding SN in the field of HIV/AIDS, and (2) the importance of SN in HIV prevention, treatment, and care. The findings of this study suggest the need for interventions using SN and the improvement of research capacity via regional collaborations to reduce the HIV burden in low- and middle-income countries.

Incarceration, Social Support Networks, and Health among Black Sexual Minority Men and Transgender Women: Evidence from the HPTN 061 Study

Support from social networks buffers against negative effects of stress but is disrupted by incarceration. Few studies examine incarceration, social support networks, and health among Black sexual minority men (BSMM) and Black transgender women (BTW). We conducted a secondary analysis using HIV Prevention Trials Network 061 (HPTN 061), a sample of BSMM/BTW recruited from six US cities. We measured associations between recent incarceration reported at six months follow-up and social support networks at twelve months follow-up, and cross-sectional associations between support networks and twelve-month health outcomes (e.g., sexual partnerships, substance use, healthcare access and depressive symptoms). Among the analytic sample (N = 1169), recent incarceration was associated with small medical support networks (adjusted risk ratio [aRR] 1.16, 95% CI 1.01, 1.34) and small financial support networks (aRR 1.18, 95% CI 1.04, 1.35). Support networks were associated with multiple partnerships (adjusted prevalence ratio [aPR] 0.77, 95% CI 0.65, 0.90), unhealthy alcohol use (aPR 1.20, 95% CI 0.96, 1.51), and depressive symptoms (aPR 1.16, 95% CI 0.99, 1.36). Incarceration adversely impacts social support networks of BSMM/BTW, and support networks were associated with a range of important health outcomes.

What is the volume, diversity and nature of recent, robust evidence for the use of peer support in health and social care? An evidence and gap map

Background

Peer support interventions involve people drawing on shared personal experience to help one another improve their physical or mental health, or reduce social isolation. If effective, they may also lessen the demand on health and social care services, reducing costs. However, the design and delivery of peer support varies greatly, from the targeted problem or need, the setting and mode of delivery, to the number and content of sessions. Robust evidence is essential for policymakers commissioning peer support and practitioners delivering services in health care and community settings. This map draws together evidence on different types of peer support to support the design and delivery of interventions.

Objectives

The aim of this map was to provide an overview of the volume, diversity and nature of recent, high quality evidence on the effectiveness and cost-effectiveness of the use of peer support in health and social care.

Search Methods

We searched MEDLINE, seven further bibliographic databases, and Epistemonikos for systematic reviews (in October 2020), randomised controlled trials (in March 2021) and economic evaluations (in May 2021) on the effectiveness of peer support interventions in health and social care. We also conducted searches of Google Scholar, two trial registers, PROSPERO, and completed citation chasing on included studies.

Selection Criteria

Systematic reviews, randomised controlled trials and economic evaluations were included in the map. Included studies focused on adult populations with a defined health or social care need, were conducted in high-income countries, and published since 2015. Any measure of effectiveness was included, as was any form of peer support providing the peer had shared experience with the participant and a formalised role.

Data Collection and Analysis

Data were extracted on the type of peer support intervention and outcomes assessed in included studies. Standardised tools were used to assess study quality for all studies: assessing the methodological quality of systematic reviews 2 for systematic reviews; Cochrane risk of bias tool for randomised controlled trials; and consensus health economic criteria list for economic evaluations.

Main Results

We included 91 studies: 32 systematic reviews; 52 randomised controlled trials; and 7 economic evaluations. Whilst most included systematic reviews and economic evaluations were assessed to be of low or medium quality, the majority of randomised controlled trials were of higher quality. There were concentrations of evidence relating to different types of peer support, including education, psychological support, self-care/self-management and social support. Populations with long-term health conditions were most commonly studied. The majority of studies measured health-related indicators as outcomes; few studies assessed cost-effectiveness. Studies were unevenly distributed geographically, with most being conducted in the USA. Several gaps were evident regarding the delivery of peer support, particularly the integration of peers and professionals in delivering support and interventions of longer duration.

Authors' Conclusions

Although there is evidence available to inform the commissioning and delivery of peer support in health and social care, there are also clear gaps that need to be addressed to further support provision, particularly regarding cost-effectiveness. The effectiveness of peer support in different countries, with varying health and social care systems, is a priority for future research, as is the integration of peers with professionals in delivering peer support.

Diagnosing PrEP Communication Self-Efficacy in a Community-Based Peer Leader Intervention for Black Sexual Minority Men

HIV prevention interventions that leverage endogenous peer leaders to communicate about Pre-Exposure Prophylaxis (PrEP) and other HIV prevention tools in their social networks offer a way to reach greater portions of communities most impacted by HIV like Black/African American gay, bisexual, same gender-loving, and other sexual minority men (BSMM). However, the success of these interventions hinge on the communication self-efficacy of its peer leaders. In this exploratory study, we present a multi-theoretical framework that situates the PrEP communication self-efficacy (PCSE) of a cohort of young BSMM peer leaders (n = 303) in the context of personal, behavioral, social, and structural factors. Using censored regression models, our analysis shows that PCSE is influenced by evaluations of PrEP itself (its relative advantage, complexity, and compatibility), network embeddedness (degree centrality) among other BSMM, social media network exposure to HIV information, and medical mistrust. We conclude with a discussion of the practical implications of our findings for intervention design and implementation.

Stigma in a Collectivistic Culture: Social Network of Female Sex Workers in China

In this egocentric network study, we explored Chinese collectivism in relation to social network characteristics and sex work-related stigma among mid-age female sex workers (FSWs). Respondent-driven sampling was used to recruit 1245 mid-age FSWs from three cities in China. We found that a one standard deviation (SD) increase in FSWs' collectivism was associated with a 0.18 SD decrease in social support (95% CI - 0.32, - 0.04), a 0.20 SD decrease in network effective size (i.e., the diversity of a social network; 95% CI - 0.30, - 0.10), and a 0.21 SD decrease in network betweenness (i.e., the "bridging potential" of egos within their networks; 95% CI - 0.33, - 0.09). Among participants who perceived more sex work stigma, the association between collectivism and FSWs' network betweenness was attenuated. In a collective culture emphasizing group values and honor, belonging to a less interconnected social network may give FSWs a structural advantage to cope with stigma and secure social support.

Association of social network characteristics with HIV knowledge, stigma, and testing: findings from a study of racial and ethnic minority women in a small Western city

Black and Latina women are disproportionately impacted by HIV/AIDS. Despite existing research linking social networks and HIV risk among men who have sex with men (MSM) and other high-risk populations, little research has examined how ethnic/racial minority women's social networks shape HIV prevention and intervention targets. Using interviews with a sample of 165 predominantly Black and Latina-identifying women from a small city in the Western U.S., this research examines the relationship between egocentric network characteristics and HIV knowledge, attitudes, and testing history. Results reveal that network characteristics play a significant role in shaping HIV-related knowledge, prejudice, and testing intention but not HIV testing history. Individual-level factors like homelessness and perceptions of testing barriers are more salient for explaining testing behaviors than network characteristics. Intervention efforts to improve knowledge and reduce prejudice among Black and Latina women may benefit from mobilizing network ties.

Performance of a Genetic Algorithm for Estimating DeGroot Opinion Diffusion Model Parameters for Health Behavior Interventions

Leveraging social influence is an increasingly common strategy to change population behavior or acceptance of public health policies and interventions; however, assessing the effectiveness of these social network interventions and projecting their performance at scale requires modeling of the opinion diffusion process. We previously developed a genetic algorithm to fit the DeGroot opinion diffusion model in settings with small social networks and limited follow-up of opinion change. Here, we present an assessment of the algorithm performance under the less-than-ideal conditions likely to arise in practical applications. We perform a simulation study to assess the performance of the algorithm in the presence of ordinal (rather than continuous) opinion measurements, network sampling, and model misspecification. We found that the method handles alternate models well, performance depends on the precision of the ordinal scale, and sampling the full network is not necessary to use this method. We also apply insights from the simulation study to investigate notable features of opinion diffusion models for a social network intervention to increase uptake of pre-exposure prophylaxis (PrEP) among Black men who have sex with men (BMSM).

The Co-Evolution of Network Structure and PrEP Adoption among a Large Cohort of PrEP Peer Leaders: Implications for Intervention Evaluation and Community Capacity-Building

Background: Peer leader interventions are effective strategies for promoting prevention behaviors in communities at risk for HIV, yet little is known about their effects on the social and behavioral dynamics of peer leaders themselves. Methods: Using data from PrEP Chicago, an RCT PrEP for prevention intervention for young Black MSM (YBMSM), we apply stochastic actor-based models to longitudinally model the impact of study participation on the online friendship and PrEP adoption dynamics among a network of peer leaders (n = 174) and a network of control group counterparts (n = 166). Results: Peer leaders assigned to the same leadership training workshop were more likely to form new Facebook friendships with one another, whereas control participants assigned to the same attention control workshop were no more or less likely to form new friendships. Further, peer leaders with greater PrEP intentions and those living with HIV were more active in forming new friendships with other peer leaders, effects not found in the control network. PrEP adoption was not influenced by network dynamics in either group. Conclusions: The implications of these findings are discussed through the lens of community-capacity building and the role that peer leader interventions and the networks they engage can impact public health.

Drug use-related stigma, safer injection norms, and hepatitis C infection among a network-based sample of young people who inject drugs

BACKGROUND

Identifying risk for hepatitis C (HCV) infection is important for understanding recent increases in HCV incidence among young people who inject drugs (PWID) in suburban and rural areas; and for refining the targeting of effective HCV preventive interventions. Much of the extant research has focused on individual health behaviors (e.g., risky drug injection behaviors) as predictors of HCV infection. The present study examines two social factors (substance use-related stigma and injection-related social norms), and the interaction between these factors, as predictors of HCV infection.

METHODS

Baseline data were used from an ongoing longitudinal study of young PWID (N = 279; mean age = 30.4 years) from the Chicago suburbs and their injection risk network members. Adjusted logistic regression models were used to examine relationships among substance use-related stigma, safer injection norms, and HCV infection.

RESULTS

Despite a marginal bivariate association between less safe injection norms and HCV infection (OR = 0.74; 95 % CI[0.39, 1.02]; p = .071), a significant stigma X norms interaction (AOR = 0.68; 95 % CI[0.51, 0.90]) suggested that at high levels of stigma, probability of HCV infection was high regardless of injection norms.

CONCLUSIONS

Findings suggest that social factors - specifically, substance use-related stigma and injection norms - are important predictors of HCV infection risk. The interaction found between these social factors suggests that intervening only to change injection norms or behaviors is likely insufficient to reduce risk for HCV infection in high-stigma settings or among high-stigma populations. Future research should develop and evaluate stigma-reduction interventions in combination with safer-injection interventions in order to maximize HCV risk reduction.

Migration, Social Networks, and HIV Sexual Risk Behaviors Among Involuntary Bachelors in Rural China

In rural China there is an abnormally high male-biased sex ratio. The result is a large number of involuntary bachelors. This study examines how migration and social networks relate to bachelors' sexual risk behaviors. Data are from a cross-sectional questionnaire survey in which 740 male respondents who had rural household registration, had never married, and were aged 28 or older were interviewed in 2017. Logistic regression reveals that both migration and social networks place the bachelors at an especially high risk of HIV transmission by increasing the chance that they engage in commercial sex, whereas only social networks are significantly associated with sexual partnership concurrency. Additionally, social networks mediate the association between migration and commercial sex. This suggests that social networks play an important role in bachelors' risk of HIV transmission and that further intervention should address their social networks.

A Pragmatic Randomized Controlled Trial to Increase PrEP Uptake for HIV Prevention: 55-Week Results From PrEPChicago

OBJECTIVES

We tested preliminary efficacy of a peer change agent type I network intervention to increase pre-exposure prophylaxis (PrEP) linkage to care among network members connected to young Black men who have sex with men.

DESIGN

Parent study is a pragmatic randomized controlled trial with 110 weeks of total follow-up. Interim midpoint analyses are performed here using participant data before crossover assignment at 55 weeks.

METHODS

We randomly assigned 423 participants in Chicago to receive the network intervention, an opinion leader workshop with telephonic booster sessions, versus a time-matched control from 2016 to 2018. The consolidated surrogate outcome was PrEP referral and linkage to clinical care among network members connected to study participants and was collected from independent administrative data.

RESULTS

Each study participant in the trial (n = 423) had on average 1822 network contacts who could be eligible for PrEP referral and linkage. During the 55-week observation period, PrEP referral was most likely to occur within 3 days of an intervention session compared to control [odds ratio (OR) 0.07 (0.02-0.013); P = 0.007] resulting in 1-2 referrals of network members per session. Network members with referral or linkage were more likely to be connected to study participants in the intervention arm than the control condition [aOR 1.50 (1.09-2.06); P = 0.012].

CONCLUSIONS

A peer change agent type I network intervention is preliminarily effective at diffusing PrEP through a network of individuals highly susceptible to HIV over 55 weeks. This low-intensity intervention demonstrated network-level impact among populations that have experienced limited PrEP care engagement in the United States.

Sociometric Risk Network Structure, HIV Prevalence, and Drug Injection-Related Norms among People Who Inject Drugs (PWID) in Athens, Greece

Background: Structural properties of sociometric networks have been associated with behaviors related to HIV transmission. Very few studies, however, have explored the correlation between sociometric network factors and drug injection-related norms. Methods: This exploratory work: (i) describes basic structural qualities of a sociometric risk network of participants in the Transmission Reduction Intervention Project (TRIP) in Athens, Greece, in the context of a large HIV outbreak among people who inject drugs (PWID); (ii) measures HIV prevalence within specific structures within the sociometric risk network of PWID in TRIP; and (iii) explores the association of structural properties of the sociometric risk network in TRIP with drug injection-related norms. Results: The sociometric risk network in TRIP consisted of a large component (n = 241, 67.8%), a few small components (n = 36, 10.1%) with 2-10 individuals each, and some isolates (n = 79, 22.2%). HIV prevalence was significantly higher in the large component (55.6%), the 2-core (59.1%) and 3-core (66.3%) of the large component, and the 3-cliques of the cores. Drug injection-related norms were significantly associated with structural characteristics of the sociometric risk network. A safe behavioral pattern (use of unclean cooker/filter/rinse water was never encouraged) was significantly (p = 0.03) less normative among people who TRIP participants of the 2-core injected with (40.5%) than among network contacts of TRIP participants outside the 2-core (55.6%). On the contrary, at drug-using venues, 2-core members reported that safer behaviors were normative compared to what was reported by those without 2-core membership. Conclusions: Sociometric network data can give useful insights into HIV transmission dynamics and inform prevention strategies.Supplemental data for this article is available online at https://doi.org/10.1080/10826084.2021.1914103 .

Individual and Social Network Structure Characteristics Associated with Peer Change Agent Engagement and Impact in a PrEP Intervention

Interventions that utilize the influence of peer change agents (PCAs) have been shown to be effective strategies for engaging key populations in HIV prevention. To date, little is known about the characteristics of PCAs associated with their effectiveness. Drawing on data from a peer leader PrEP intervention for young Black men who have sex with men (YBMSM) (N = 423), we evaluated the effects of experiential (i.e., living with HIV, PrEP awareness, PrEP use), psychographic (i.e., self-perceived leadership, innovativeness), and network (i.e., degree centrality, eigenvector centrality, and brokerage) characteristics on three effectiveness outcomes: (1) recruiting peers into the study; (2) completing "booster" sessions; and (3) linking peers to PrEP care. For each outcome, multivariable regressions were performed. On average, PCAs recruited 0.89 peers, completed 1.99 boosters, and had 1.33 network peers linked to PrEP care. Experiential factors: Prior PrEP awareness was positively associated with booster completion. Network factors: Being a network broker (i.e., connecting otherwise disconnected communities) was positively associated with peer recruitment but negatively associated with linking peers to PrEP, and degree centrality (i.e., the number of network connections someone has) and eigenvector centrality (i.e., being connected to well-connected network associates) were positively associated with linking peers to PrEP. Psychographic characteristics were not associated with any outcome. These findings can be used to inform PCA selection and to identify subpopulations who require additional support to excel as PCAs.

HIV Prevalence and Associated Risks in a Respondent-Driven Sample of Illicit Stimulant Users in a Southern United States City

Stimulant abuse is a major contributor to HIV transmission in the United States, yet HIV prevalence among persons who use illicit stimulants remains unknown. We implemented respondent driven sampling (RDS) to estimate the prevalence of HIV infection in this high-risk population. We also examined RDS-adjusted rates of risk behaviors among HIV-positive and HIV-negative participants. Recruited from seven seeds, our sample of 387 participants was 46% female, 89% African American, and 45.94 years old on average. Participants were predominantly non-injection cocaine users, had large networks of stimulant users, and reported an established relationship with their recruiter. The adjusted population proportion of HIV infection was 0.07 (0.04, 0.11). The majority of sexually active participants reported engagement in risk behaviors (73%), but rates generally did not differ by HIV status. Our results highlight that stimulant use is a risk factor for HIV infection. This study also demonstrates that RDS is a very effective strategy for reaching stimulant users in the community.

Peer education for HIV prevention among high-risk groups: a systematic review and meta-analysis

Background

Peer education has become a strategy for health promotion among high-risk groups for HIV infection worldwide. However, the extent to which peer education could have an impact on HIV prevention or the long-term effect of this impact is still unknown. This study thus quantifies the impact of peer education over time among high-risk HIV groups globally.

Method

Following the PRISMA guidelines, a systematic review and meta-analysis was used to assess the effects and duration of peer education. A thorough literature search of PubMed, Web of Science, Embase and Cochrane Library was performed, and studies about peer education on high-risk HIV groups were reviewed. Pooled effects were calculated and the sources of heterogeneity were explored using meta-regression and subgroup analysis.

Results

A total of 60 articles with 96,484 subjects were identified, and peer education was associated with 36% decreased rates of HIV infection among overall high risk groups (OR: 0.64; 95%CI: 0.47–0.87). Peer education can promote HIV testing (OR = 3.19; 95%CI:2.13,4.79) and condom use (OR = 2.66, 95% CI: 2.11–3.36) while reduce equipment sharing (OR = 0.50; 95%CI:0.33,0.75) and unprotected sex (OR = 0.82; 95%CI: 0.72–0.94). Time trend analysis revealed that peer education had a consistent effect on behavior change for over 24 months and the different follow-up times were a source of heterogeneity.

Conclusion

Our study shows that peer education is an effective tool with long-term impact for behavior change among high-risk HIV groups worldwide. Low and middle-income countries are encouraged to conduct large-scale peer education.

Social network strategy as a promising intervention to better reach key populations for promoting HIV prevention: a systematic review and meta-analysis

INTRODUCTION

Key populations such as men who have sex with men (MSM), drug users and sex workers are at high risk of HIV infection, but they are marginalised and hidden. Social network strategy (SNS) is purposeful to use social networks to generate social influence, accelerate behaviour change and achieve desirable outcomes among individuals or communities and have been increasingly used for HIV interventions. This study aims to investigate the effects of SNS on HIV prevention among key populations.

METHODS

We searched six databases, including PubMed, Web of Science, Embase, Cochrane Library, ScienceDirect and Wiley for randomised controlled trials published between January 1999 and May 2019. Eligibility criteria included SNS conducted among key populations for HIV interventions, with a comparator group. Outcomes included changes in HIV high-risk behaviour, HIV seroconversion and other HIV outcomes. We used the risk ratio (RR) or mean difference with associated 95% confidence interval (CI) to assess the comparative efficacy between SNS and control methods on the selected outcomes. The GRADE system was used to assess the quality of evidence for the studies.

RESULTS

Of 2818 citations identified, 28 trails from 24 papers met the inclusion criteria. The results showed that SNS was associated with less unprotected intercourse (RR 0.79, 95% CI 0.72 to 0.86) and sex with multiple partners (0.46, 95% CI 0.33 to 0.65). Additionally, relative to the control methods, SNS significantly reduced HIV seroconversion (0.65, 95% CI 0.53 to 0.81), improved HIV testing uptake (1.11, 95% CI 1.07 to 1.15) and promoted participant retention (1.03, 95% CI 1.00 to 1.06) among key populations. The Grading of Recommendations Assessment, Development and Evaluation system showed that trails were of moderate quality.

CONCLUSIONS

This review provides evidence that SNS can reach key populations who are currently not being reached by existing programmes and deliver HIV interventions through social networks, which decreases HIV sexual risk behaviour and HIV incidence and increases HIV testing uptake and participant retention.

TRIAL REGISTRATION NUMBER

CRD42019140533.

Promoting Transformative Community Change for Equitable Health: Peer Education and Intervention for Pre-Exposure HIV Prophylaxis

Many new HIV infections occur through individuals who are unaware of their HIV status. HIV disparities are more prevalent among underserved populations, and the number of new cases in the U.S. is highest in the Southern region. Using the Social Network Intervention, 63 undergraduate students delivered a face-to-face, communication-centered, peer education to 333 peers in the underserved communities; of those, 220 verified cases were analyzed. A baseline assessment was followed by the intervention and the second assessment, with the third assessment 2 weeks later. Assessments measured intervention impacts on health information sharing, knowledge about HIV/AIDS, and the dimensions of vested interest theory. The peer education was effective in making changes in participants' vestedness, knowledge regarding HIV/AIDS, and trust and expectation toward informational sources. Communication and tailored messages through established relationship channels were proven crucial for promoting positive behaviors about HIV sexual health, with strong evidence of change in stigma and the culture of silence.

Egocentric Health Networks and Cardiovascular Risk Factors in the ECHORN Cohort Study

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in the Caribbean region.

OBJECTIVE

This study explored the concept of a health network, relationships focused on health-related matters, and examined associations with CVD risk factors in the Eastern Caribbean.

DESIGN

The Eastern Caribbean Health Outcomes Research Network Cohort Study is an ongoing longitudinal cohort being conducted in the US Virgin Islands, Puerto Rico, Trinidad and Tobago, and Barbados.

PARTICIPANTS

Participants (n = 1989) were English or Spanish-speaking adults 40 years and older, who were residents of the island for at least 10 years, and who intended to live on-island for the next 5 years.

MAIN MEASURES

Logistic regression was used to examine associations between health network characteristics and CVD risk factors: physical activity, hypertension, and smoking. A baseline survey asked questions about health networks using name generator questions that assessed who participants spoke to about health matters, whose opinions on healthcare mattered, and who they would trust to make healthcare decisions on their behalf.

KEY RESULTS

Health networks were mainly comprised of family members and friends. Healthcare professionals comprised 7% of networks, mean network size was four, and 74% of health network contacts were perceived to be in "good" to "excellent" health. Persons with larger health networks had greater odds of being physically active compared with those with smaller networks (OR = 1.07, CI = 1.01-1.14).

CONCLUSIONS

Health networks may be useful to intervention efforts for CVD risk factor reduction. More studies are needed to examine health networks in Caribbean contexts and explore associations with other CVD risk factors.

New Measures for Research on Men Who Have Sex with Men and for At-Risk Heterosexuals: Tools to Study Links Between Structural Interventions or Large-Scale Social Change and HIV Risk Behaviors, Service Use, and Infection

Large-scale structural interventions and "Big Events" like revolutions, wars and major disasters can affect HIV transmission by changing the sizes of at-risk populations, making high-risk behaviors more or less likely, or changing contexts in which risk occurs. This paper describes new measures to investigate hypothesized pathways that could connect macro-social changes to subsequent HIV transmission. We developed a "menu" of novel scales and indexes on topics including norms about sex and drug injecting under different conditions, experiencing denial of dignity, agreement with cultural themes about what actions are needed for survival or resistance, solidarity and other issues. We interviewed 298 at-risk heterosexuals and 256 men who have sex with men in New York City about these measures and possible validators for them. Most measures showed evidence of criterion validity (absolute magnitude of Pearson's r ≥ 0.20) and reliability (Cronbach's alpha ≥ 0.70). These measures can be (cautiously) used to understand how macro-changes affect HIV and other risk. Many can also be used to understand risk contexts and dynamics in more normal situations. Additional efforts to improve and to replicate the validation of these measures should be conducted.

Using Social Norms to Change Behavior and Increase Sustainability in the Real World: A Systematic Review of the Literature

Behavioral change interventions based on social norms have proven to be a popular and cost-effective way in which both researchers and practitioners attempt to transform behavior in order to increase environmental and social sustainability in real-world contexts. In this paper, we present a systematic review of over 90 empirical studies that have applied behavioral change interventions based on social norms in field settings. Building on previous research about the sources of information that people use to understand social norms and other local determinants of behavior, we propose a framework organized along two axes that describe intervention context (situated interventions applied in the same context where the target behavior happens versus remote interventions that are applied away from that context) and type of normative information leveraged (interventions that provide summary information about a group versus interventions that expose participants to the opinions and behaviors of others). We also illustrate successful applications for each dimension, as well as the social, psychological and physical determinants of behavior that were leveraged to support change. Finally, based on our results, we discuss some of the elements and practical mechanisms that can be used by both researchers and practitioners to design more integral, effective and sustainable social norm intervention in the real world.

Role of Social Network Sexual Norms and Behaviors on the HIV Sexual Risk Behaviors of People Who Inject Drugs in HPTN 037

This study examined the effect of social network descriptive sexual norms and behaviors on the sexual behaviors of people who inject drugs (PWID). Data from HPTN037 of 232 PWID (egos) and 464 network members (alters) were used in multilevel multivariate logistic regression models. Egos whose alters reported multiple sex partners had greater odds of multiple sex partners (aOR 2.20, 1.13-4.29). Egos' norms of condomless sex with primary (aOR 2.67, 1.15-6.17) and casual (aOR 2.38, 1.01-5.59) partners and egos' norms of giving (aOR 5.52, 1.87-16.25) and receiving (aOR 7.38, 1.34-40.66) money/drugs for sex were associated with the egos' respective behaviors. History of sex between an ego and alter was not associated with increased influence of alters' norms and behaviors on egos' sexual behavior. Findings provide support for developing interventions that target descriptive norms and selective network behavioral characteristics to decrease sexual HIV risk behavior among PWID.

Assessing Individual and Disseminated Effects in Network-Randomized Studies

Implementation trials often involve clustering via risk networks, where only some participants directly receive the intervention. The individual effect is that among directly treated persons beyond being in an intervention network; the disseminated effect is that among persons engaged with those directly treated. In this article, we employ a causal inference framework and discuss assumptions and estimators for individual and disseminated effects and apply them to the HIV Prevention Trials Network 037 Study. HIV Prevention Trials Network 037 was a phase III, network-level, randomized controlled human immunodeficiency virus (HIV) prevention trial conducted in the United States and Thailand from 2002 to 2006 that recruited injection drug users, who were assigned to either an intervention group or a control group, and their risk network members, who received no direct intervention. Combining individual and disseminated effects, we observed a 35% composite rate reduction in the adjusted model (risk ratio = 0.65, 95% confidence interval: 0.47, 0.90). Methodology is now available for estimating the full set of these effects, enhancing knowledge gained from network-randomized trials. Although the overall effect gains validity from network randomization, we show that it will generally be less than the composite effect. Additionally, if only index participants benefit from the intervention, as the network size increases, the overall effect tends toward the null-an unfortunate and misleading conclusion.

Strategic Players for Identifying Optimal Social Network Intervention Subjects

We present a method whereby social network ties are used to identify behavioral leaders who are situated in the network such that these individuals are: 1) able to influence other individuals who are in need of and most receptive to intervention, thereby maximizing the impact of the intervention; and 2) not embedded with ties that are likely to be behaviorally antagonistic to the intervention or that would compromise the optimal evaluation of intervention efficacy. In this study we developed a novel method which we call Strategic Players, which is a solution for identifying a set of players who are close to a target subset of the network (i.e., the targeted group), and far away from the subset we wish to avoid (i.e. the avoidance group). This solution seeks to maximize the diffusion of the behavior to the targeted group while minimizing contact and influence from the avoidance group. We apply this method to two different social networks.

Sexual health information-seeking behavior on a social media site: predictors of best answer selection

Purpose

The purpose of this paper is to identify sexual health information needs and the cognitive and affective factors correlated with the best answer chosen by social Q&A users.

Design/methodology/approach

The study collected questions and answers regarding sexual health information on a social Q&A site, and analyzed the questions and a paired sample composed of best and non-best answers (n=480).

Findings

The main information needs of consumers are human development, sexual behavior, and sexual health. Best answers are more likely to include both cognitive (higher level of readability, risky information, social norms) and affective factors (empathy, positive/negative feelings, and optimistic information) than non-best answers.

Research limitations/implications

The study illuminates the roles of social Q&A as a unique platform to discuss sensitive health topics due to the fact that consumers use such social media sites as critical complementary health information sources.

Practical implications

If health information providers develop information with the factors that the study suggests, not only will it be more adopted by consumers, but it will also ameliorate the quality concerns about online health information.

Originality/value

Previous studies only investigated the most prevalent factors, rather than the most effective ones, which have a greater influence on best answer selection. This study compares the best answers and the non-best answers to overcome the limitations of the previous studies. Above all, the study applied the persuasion concepts to address the cognitive and affective perspectives to the answer evaluations of social Q&A.

Feasibility of ecological momentary assessment to study mood and risk behavior among young people who inject drugs

AIMS

To test the acceptability and feasibility of ecological momentary assessment (EMA) of mood and injection risk behavior among young people who inject drugs (PWID), using mobile phones.

METHODS

Participants were 185 PWID age 18-35 recruited from two sites of a large syringe service program in Chicago. After completing a baseline interview, participants used a mobile phone app to respond to momentary surveys on mood, substance use, and injection risk behavior for 15 days. Participants were assigned to receive surveys 4, 5, or 6 times per day.

RESULTS

Participants were 68% male, 61% non-Hispanic white, 24% Hispanic, and 5% non-Hispanic Black. Out of 185 participants, 8% (n = 15) failed to complete any EMA assessments. Among 170 EMA responders, the mean number of days reporting was 10 (SD 4.7), the mean proportion of assessments completed was 0.43 (SD 0.27), and 76% (n = 130) completed the follow-up interview. In analyses adjusted for age and race/ethnicity, women were more responsive than men to the EMA surveys in days reporting (IRR = 1.33, 95% CI 1.13-1.56), and total number of surveys completed (IRR = 1.51, 95% CI 1.18-1.93). Homeless participants responded on fewer days (IRR = 0.76, 95% CI 0.64-0.90) and completed fewer surveys (IRR = 0.70, 95% CI 0.54-0.91), and were less likely to return for follow-up (p = 0.016). EMA responsiveness was not significantly affected by the number of assigned daily assessments.

CONCLUSIONS

This study demonstrated high acceptability and feasibility of EMA among young PWID, with up to 6 survey prompts per day. However, homelessness significantly hampered successful participation.

Network Research Experiences in New York and Eastern Europe: Lessons for the Southern US in Understanding HIV Transmission Dynamics

PURPOSE

This paper presents an overview of different kinds of risk and social network methods and the kinds of research questions each can address.

RECENT FINDINGS

It also reviews what network research has discovered about how network characteristics are associated with HIV and other infections, risk behaviors, preventive behaviors, and care, and discusses some ways in which network-based public health interventions have been conducted. Based on this, risk and social network research and interventions seem both feasible and valuable for addressing the many public health and social problems raised by the widespread use of opioids in the US South.

Racial Inequities in HIV Prevalence and Composition of Risk Networks Among People Who Inject Drugs in HIV Prevention Trial Network 037

BACKGROUND

HIV prevention interventions in the United States have failed to eliminate racial inequities. Here, we evaluate factors associated with racial inequities in HIV prevalence among people who inject drugs using HIV Prevention Trial Network 037 data.

METHODS

We measured racial homophily (ie, all members share the same race), being in an HIV+ network (network with ≥1 HIV+ member), and drug and sex risk behaviors. A 2-level logistic regression with a random intercept evaluated the association between being in an HIV+ network and race adjusting for individual-level and network-level factors.

RESULTS

Data from 232 index participants and 464 network members were included in the analysis. Racial homophily was high among blacks (79%) and whites (70%); 27% of all-black, 14% of all-white, and 23% of racially mixed networks included HIV+ members. Sex risk was similar across networks, but needle sharing was significantly lower in all-black (23%) compared with all-white (48%) and racially mixed (46%) networks. All-black [adjusted odds ratio (AOR), 3.6; 95% confidence interval (CI), 1.4 to 9.5] and racially mixed (AOR, 2.0; 95% CI: 1.1 to 3.7) networks were more likely to include HIV+ network members; other factors associated with being in HIV+ network included homelessness (AOR, 2.0; 95% CI, 1.2 to 3.2), recent incarceration (AOR, 0.4; 95% CI, 0.2 to 0.7), and cocaine injection (AOR, 1.7; 95% CI, 1.0 to 2.7). Risk behaviors were not associated with being in an HIV+ network.

CONCLUSION

Despite having lower drug risk behavior, all-black networks disproportionately included HIV+ members. HIV prevention interventions for people who inject drugs need to go beyond individual risk and consider the composition of risk networks.

Gender differences in substance use treatment and substance use among adults on probation

BACKGROUND

Although many formal and informal substance use treatment programs were originally designed for men, no studies have investigated how gender affects the use of substance use treatment modalities, and how gender differences in treatment utilization impact substance use in the unique probation context.

OBJECTIVE

To describe gender differences in use and effectiveness of substance use treatment modalities (formal and informal) among probationers.

METHODS

Longitudinal data were obtained from 335 individuals (93 women) who participated in the Motivational Assessment Program to Initiate Treatment (MAPIT) study. Timeline follow-back measures were used to quantify daily substance use and treatment modality (formal treatment included inpatient and outpatient treatment; informal treatment included self-help, religious, and all other group meetings). Multivariate generalized estimating equations were used to examine relationships between gender, treatment, and substance use.

RESULTS

Gender was not associated with alcohol use. Use of formal treatment programs reduced the odds of alcohol use by 15%. The probability of alcohol use was the lowest (8%) for men who participated in formal treatment. For men using informal treatment programs, the probability of alcohol use was 11%. The probability of alcohol use for women was similar regardless of the type of treatment utilization (15-16%). No differences in illicit drug use by gender or type of treatment were detected.

CONCLUSION

This research found limited evidence of a relationship between gender, substance use treatment modality, and alcohol use. These findings have clinical significance in that both formal and informal treatment approaches are similarly effective across both men and women.

Gender and race as correlates of high risk sex behaviors among injection drug users at risk for HIV enrolled in the HPTN 037 study

BACKGROUND

Sexual contact has been shown to be a major mode of HIV transmission among people who inject drugs (PWID). This study examined gender and racial differences among PWID' sexual risk behaviors from the perspective of sexual scripts.

METHODS

696 PWID enrolled from Philadelphia on HPTN 037 were classified as engaging in high-risk sex behaviors if they reported having sex in the past 30 days and condomless sex with a non-primary partner, giving/receiving sex for money, or multiple partners. A multivariable logistic regression model was used to assess associations between demographic factors and high risk sex.

RESULTS

Findings of the multivariable regression analysis demonstrated that being White (OR = 0.52, p < 0.001) and male (OR = 0.59, p = 0.002) were protective of high risk sex, while homelessness (OR = 1.7, p = 0.005), and being single (OR = 1.83, p = 0.006) were positively associated with high risk sex. African American (AA) women were 1.7 times more likely to report high-risk sex than AA men (p = 0.002), 3.28 times more likely than White men (p < 0.001), and 1.93 times more likely than White women (p < 0.001).

CONCLUSIONS

Since AA women report high-risk sex behaviors more than other demographic groups, behavioral interventions for HIV risk reduction among PWID may benefit from focusing on sex-risk reduction among AA women.

Project nGage: Results of a Randomized Controlled Trial of a Dyadic Network Support Intervention to Retain Young Black Men Who Have Sex With Men in HIV Care

HIV-positive young black MSM (YBMSM) experience poor outcomes along the HIV care continuum, yet few interventions have been developed expressly for YBMSM retention in care. Project nGage was a randomized controlled trial conducted across five Chicago clinics with 98 HIV-positive YBMSM aged 16-29 between 2012 and 2015. The intervention used a social network elicitation approach with index YBMSM (n = 45) to identify and recruit a support confidant (SC) to the study. Each index-SC dyad met with a social worker to improve HIV-care knowledge, activate dyadic social support, and develop a retention in care plan. Each index and SC also received four mini-booster sessions. Control participants (n = 53) received treatment as usual. Surveys and medical records at baseline, 3-, and 12-months post-intervention assessed visit history (3 or more visits over 12 months; primary outcome), and sociodemographic, network, social-psychological, and behavioral factors. At baseline, there were no differences in age (M = 23.8 years), time since diagnosis (M ≤ 2 years), clinic visits in the previous 12 months (M = 4.1), and medication adherence (68.6 ≥ 90% adherence). In multivariate logistic regression analysis, intervention participants were 3.01 times more likely to have had at least 3 provider visits (95% CI 1.0-7.3) than were control participants over 12 months. Project nGage demonstrates preliminary efficacy in improving retention in care among YBMSM. Results suggest that engaging supportive network members may improve key HIV care continuum outcomes.

Preventing blood-borne virus infection in people who inject drugs in the UK: systematic review, stakeholder interviews, psychosocial intervention development and feasibility randomised controlled trial

BACKGROUND

Opioid substitution therapy and needle exchanges have reduced blood-borne viruses (BBVs) among people who inject drugs (PWID). Some PWID continue to share injecting equipment.

OBJECTIVES

To develop an evidence-based psychosocial intervention to reduce BBV risk behaviours and increase transmission knowledge among PWID, and conduct a feasibility trial among PWID comparing the intervention with a control.

DESIGN

A pragmatic, two-armed randomised controlled, open feasibility trial. Service users were Steering Group members and co-developed the intervention. Peer educators co-delivered the intervention in London.

SETTING

NHS or third-sector drug treatment or needle exchanges in Glasgow, London, Wrexham and York, recruiting January and February 2016.

PARTICIPANTS

Current PWID, aged ≥ 18 years.

INTERVENTIONS

A remote, web-based computer randomisation system allocated participants to a three-session, manualised, psychosocial, gender-specific group intervention delivered by trained facilitators and BBV transmission information booklet plus treatment as usual (TAU) (intervention), or information booklet plus TAU (control).

MAIN OUTCOME MEASURES

Recruitment, retention and follow-up rates measured feasibility. Feedback questionnaires, focus groups with participants who attended at least one intervention session and facilitators assessed the intervention's acceptability.

RESULTS

A systematic review of what works to reduce BBV risk behaviours among PWID; in-depth interviews with PWID; and stakeholder and expert consultation informed the intervention. Sessions covered improving injecting technique and good vein care; planning for risky situations; and understanding BBV transmission. Fifty-six per cent (99/176) of eligible PWID were randomised: 52 to the intervention group and 47 to the control group. Only 24% (8/34) of male and 11% (2/18) of female participants attended all three intervention sessions. Overall, 50% (17/34) of men and 33% (6/18) of women randomised to the intervention group and 47% (14/30) of men and 53% (9/17) of women randomised to the control group were followed up 1 month post intervention. Variations were reported by location. The intervention was acceptable to both participants and facilitators. At 1 month post intervention, no increase in injecting in 'risky' sites (e.g. groin, neck) was reported by participants who attended at least one session. PWID who attended at least one session showed a trend towards greater reduction in injecting risk behaviours, a greater increase in withdrawal planning and were more confident about finding a vein. A mean cost of £58.17 per participant was calculated for those attending one session, £148.54 for those attending two sessions and £270.67 for those attending all three sessions, compared with £0.86 in the control group. Treatment costs across the centres vary as a result of the different levels of attendance, as total session costs are divided by attendees to obtain a cost per attendee. The economic analysis suggests that a cost-effectiveness study would be feasible given the response rates and completeness of data. However, we have identified aspects where the service use questionnaire could be abbreviated given the low numbers reported in several care domains. No adverse events were reported.

CONCLUSIONS

As only 19% of participants attended all three intervention sessions and 47% were followed up 1 month post intervention, a future definitive randomised controlled trial of the intervention is not feasible. Exposure to information on improving injecting techniques did not encourage riskier injecting practices or injecting frequency, and benefits were reported among attendees. The intervention has the potential to positively influence BBV prevention. Harm reduction services should ensure that the intervention content is routinely delivered to PWID to improve vein care and prevent BBVs.

FUTURE WORK

The intervention did not meet the complex needs of some PWID, more tailoring may be needed to reach PWID who are more frequent injectors, who are homeless and female.

LIMITATIONS

Intervention delivery proved more feasible in London than other locations. Non-attendance at the York trial site substantially influenced the results.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN66453696 and PROSPERO 014:CRD42014012969.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 72. See the NIHR Journals Library website for further project information.

PrEP Chicago: A randomized controlled peer change agent intervention to promote the adoption of pre-exposure prophylaxis for HIV prevention among young Black men who have sex with men

BACKGROUND/AIMS

Advances in biomedical prevention strategies such as pre-exposure prophylaxis (PrEP) represent a new opportunity for reducing HIV incidence among young Black men who have sex with men, for whom the number of new HIV infections continues to rise. However, studies have documented low rates of PrEP uptake in this community. Research suggests that the peer networks of young Black men who have sex with men play important roles in their sexual health decisions. PrEP Chicago is a randomized controlled trial network intervention designed to increase PrEP uptake among young Black men who have sex with men living in Chicago. The aims of this study are twofold. Aim 1 is to estimate the effectiveness of a peer change agent intervention for (1) increasing the number of referrals made to a PrEP information line, (2) increasing the rate of PrEP adoption among non-participant peers, and (3) increasing PrEP knowledge, attitudes, and intentions among participants. Aim 2 is to determine the individual and network variables that explain peer change agent effectiveness.

METHODS

PrEP Chicago is a social network intervention that utilizes the influence of peer change agents to link young Black men who have sex with men in Chicago to PrEP. Young Black men who have sex with men were recruited using respondent-driven sampling. Once screened for eligibility, participants were randomly assigned to either one of two treatment sequences: (1) intervention treatment in Year 1 followed by a minimal contact attention control in Year 2 or (2) the minimal contact attention control in Year 1 followed by treatment in Year 2. The treatment consists of a PrEP/peer change agent training workshop followed by booster calls for 12 months. The attention control consists of a sex diary activity designed to help participants assess sexual risk. Psychosocial, sexual health, and network data are collected from all participants at baseline and at 12- and 24-month follow-ups.

RESULTS

In total, 423 participants aged 18-35 have been enrolled (more than 100% target enrollment) and have completed baseline data collection. A majority of participants in both intervention and control groups reported having heard of PrEP before enrolling in the study, yet also reported having had no current or prior experience taking PrEP. Statistical analyses await completion of Year 1 of the trial in March 2018.

CONCLUSION

PrEP Chicago addresses a gap in HIV prevention research and intervention design by utilizing the existing social networks among young Black men who have sex with men as mechanisms for information diffusion, behavioral influence, social support, and empowerment. Therefore, interventions that leverage peer influence processes to facilitate PrEP uptake are promising strategies to improve sexual health engagement and overcome disparities in outcomes among this at-risk population.

A Systematic Review and Meta-analysis of Psychosocial Interventions to Reduce Drug and Sexual Blood Borne Virus Risk Behaviours Among People Who Inject Drugs

Opiate substitution treatment and needle exchanges have reduced blood borne virus (BBV) transmission among people who inject drugs (PWID). Psychosocial interventions could further prevent BBV. A systematic review and meta-analysis examined whether psychosocial interventions (e.g. CBT, skills training) compared to control interventions reduced BBV risk behaviours among PWID. 32 and 24 randomized control trials (2000-May 2015 in MEDLINE, PsycINFO, CINAHL, Cochrane Collaboration and Clinical trials, with an update in MEDLINE to December 2016) were included in the review and meta-analysis respectively. Psychosocial interventions appear to reduce: sharing of needles/syringes compared to education/information (SMD −0.52; 95% CI −1.02 to −0.03; I² = 10%; p = 0.04) or HIV testing/counselling (SMD −0.24; 95% CI −0.44 to −0.03; I² = 0%; p = 0.02); sharing of other injecting paraphernalia (SMD −0.24; 95% CI −0.42 to −0.06; I² = 0%; p < 0.01) and unprotected sex (SMD −0.44; 95% CI −0.86 to −0.01; I² = 79%; p = 0.04) compared to interventions of a lesser time/intensity, however, moderate to high heterogeneity was reported. Such interventions could be included with other harm reduction approaches to prevent BBV transmission among PWID.

Review of Recent Methodological Developments in Group-Randomized Trials: Part 2-Analysis

In 2004, Murray et al. reviewed methodological developments in the design and analysis of group-randomized trials (GRTs). We have updated that review with developments in analysis of the past 13 years, with a companion article to focus on developments in design. We discuss developments in the topics of the earlier review (e.g., methods for parallel-arm GRTs, individually randomized group-treatment trials, and missing data) and in new topics, including methods to account for multiple-level clustering and alternative estimation methods (e.g., augmented generalized estimating equations, targeted maximum likelihood, and quadratic inference functions). In addition, we describe developments in analysis of alternative group designs (including stepped-wedge GRTs, network-randomized trials, and pseudocluster randomized trials), which require clustering to be accounted for in their design and analysis.

Review of Recent Methodological Developments in Group-Randomized Trials: Part 1-Design

In 2004, Murray et al. reviewed methodological developments in the design and analysis of group-randomized trials (GRTs). We have highlighted the developments of the past 13 years in design with a companion article to focus on developments in analysis. As a pair, these articles update the 2004 review. We have discussed developments in the topics of the earlier review (e.g., clustering, matching, and individually randomized group-treatment trials) and in new topics, including constrained randomization and a range of randomized designs that are alternatives to the standard parallel-arm GRT. These include the stepped-wedge GRT, the pseudocluster randomized trial, and the network-randomized GRT, which, like the parallel-arm GRT, require clustering to be accounted for in both their design and analysis.

Evaluating network-level predictors of behavior change among injection networks enrolled in the HPTN 037 randomized controlled trial

BACKGROUND

Little is known about ways network-level factors that may influence the adoption of combination prevention behaviors among injection networks, or how network-oriented interventions might moderate this behavior change process.

METHODS

A total of 232 unique injection risk networks in Philadelphia, PA, were randomized to a peer educator network-oriented intervention or standard of care control arm. Network-level aggregates reflecting the injection networks' baseline substance use dynamics, social interactions, and the networks exposure to gender- and structural-related vulnerabilities were calculated and used to predict changes in the proportion of network members adopting safer injection practices at 6-month follow-up.

RESULTS

At follow-up, safer injection practices were observed among 46.31% of a network's members on average. In contrast, 25.7% of networks observed no change. Controlling for the effects of the intervention, significant network-level factors influencing network-level behavior change reflected larger sized injection networks (b=2.20, p=0.013) with a greater proportion of members who shared needles (b=0.29, p<0.001) and engaged in poly drug use at baseline (b=6.65, p=0.021). Changes in a network's safer injection practices were also observed for networks with fewer new network members (b=-0.31, p=0.008), and for networks whose members were proportionally less likely to have experienced incarceration (b=-0.20, p=0.012) or more likely to have been exposed to drug treatment (b=0.17, p=0.034) in the 6-months prior to baseline. A significant interaction suggested the intervention uniquely facilitated change in safer injection practices among female-only networks (b=-0.32, p=0.046).

CONCLUSIONS

Network-level factors offer insights into ways injection networks might be leveraged to promote combination prevention efforts.

Social causation and neighborhood selection underlie associations of neighborhood factors with illicit drug-using social networks and illicit drug use among adults relocated from public housing

Theories of social causation and social influence, which posit that neighborhood and social network characteristics are distal causes of substance use, are frequently used to interpret associations among neighborhood characteristics, social network characteristics and substance use. These associations are also hypothesized to result from selection processes, in which substance use determines where people live and who they interact with. The potential for these competing selection mechanisms to co-occur has been underexplored among adults. This study utilizes path analysis to determine the paths that relate census tract characteristics (e.g., economic deprivation), social network characteristics (i.e., having ≥ 1 illicit drug-using network member) and illicit drug use, among 172 African American adults relocated from public housing in Atlanta, Georgia and followed from 2009 to 2014 (7 waves). Individual and network-level characteristics were captured using surveys. Census tract characteristics were created using administrative data. Waves 1 (pre-relocation), 2 (1st wave post-relocation), and 7 were analyzed. When controlling for individual-level sociodemographic factors, residing in census tracts with prior economic disadvantage was significantly associated with illicit drug use at wave 1; illicit drug use at wave 1 was significantly associated with living in economically-disadvantaged census tracts at wave 2; and violent crime at wave 2 was associated with illicit drug-using social network members at wave 7. Findings from this study support theories that describe social causation and neighborhood selection processes as explaining relationships of neighborhood characteristics with illicit drug use and illicit drug-using social networks. Policies that improve local economic and social conditions of neighborhoods may discourage substance use. Future studies should further identify the barriers that prevent substance users from obtaining housing in less disadvantaged neighborhoods.