Including Online-Recruited Seeds: A Respondent-Driven Sample of Men Who Have Sex With Men

Recruitment of Young Gay, Bisexual, and Other Men Who Have Sex With Men for a Web-Based Human Papillomavirus Vaccination Intervention: Differences in Participant Characteristics and Study Engagement by Recruitment Source in a Randomized Controlled Trial

BACKGROUND

Young gay, bisexual, and other men who have sex with men have been referred to as a "hard-to-reach" or "hidden" community in terms of recruiting for research studies. With widespread internet use among this group and young adults in general, web-based avenues represent an important approach for reaching and recruiting members of this community. However, little is known about how participants recruited from various web-based sources may differ from one another.

OBJECTIVE

This study aimed to determine how young gay, bisexual, and other men who have sex with men recruited from various web-based sources differ from one another in terms of participant characteristics and study engagement.

METHODS

Data were collected as part of a randomized controlled trial of Outsmart HPV, a web-based human papillomavirus (HPV) vaccination intervention for young gay, bisexual, and other men who have sex with men. From 2019 to 2021, we recruited young gay, bisexual, and other men who have sex with men in the United States who were aged 18-25 years and not vaccinated against HPV (n=1227) through various web-based avenues. We classified each participant as being recruited from either (1) social media (eg, Facebook, Instagram, Snapchat), (2) a dating app (eg, Grindr, Scruff), or (3) some other digital recruitment source (eg, existing research panel, university-based organization). Analyses compared participants from these 3 groups on demographic and health-related characteristics and metrics involving study engagement.

RESULTS

Most demographic and health-related characteristics differed by web-based recruitment source, including race or ethnicity (P<.001), relationship status (P<.001), education level (P<.001), employment status (P<.001), sexual self-identity (P<.001), health insurance status (P<.001), disclosure of sexual orientation (P=.048), and connectedness to the LGBTQ (lesbian, gay, bisexual, transgender, queer) community (P<.001) The type of device used by participants during study enrollment also differed across groups, with smartphone use higher among participants recruited via dating apps (n=660, 96.6%) compared to those recruited via social media (n=318, 78.9%) or other digital sources (n=85, 60.3%; P<.001). Participants recruited via social media were more likely than those recruited via dating apps to complete follow-up surveys at 3 different timepoints (odds ratios 1.52-2.09, P=.001-.008). These participants also spent a longer amount of time viewing intervention content about HPV vaccination (3.14 minutes vs 2.67 minutes; P=.02).

CONCLUSIONS

We were able to recruit a large national sample of young gay, bisexual, and other men who have sex with men for a web-based HPV vaccination intervention via multiple methodologies. Participants differed on a range of demographic and health-related characteristics, as well as metrics related to study engagement, based on whether they were recruited from social media, a dating app, or some other digital recruitment source. Findings highlight key issues and considerations that can help researchers better plan and customize future web-based recruitment efforts of young gay, bisexual, and other men who have sex with men.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04032106; https://clinicaltrials.gov/study/NCT04032106.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.2196/16294.

Understanding the Association Between Medical Mistrust and Unmet Medical Care Need in Gender and Sexually Diverse People of Color Assigned Female at Birth

Purpose: The present study investigated associations of sexual orientation and/or gender identity-based medical mistrust and racial/ethnic-based medical mistrust, respectively, with unmet medical care need among lesbian, gay, bisexual, transgender, queer, and/or sexually or gender diverse (LGBTQ+) people of color (POC) assigned female at birth (AFAB). We also tested the interaction of the two types of medical mistrust on unmet medical care need. Methods: Participants were 266 LGBTQ+ POC AFAB. Participants completed measures of medical mistrust based on race/ethnicity and LGBTQ+ identity. Unmet medical care need was assessed using the item: "During the past 12 months, was there ever a time where you felt that you needed health care but you didn't receive it?" Multivariate logistic regression models were run with either type of medical mistrust, as well as their interaction, as the predictor and unmet medical care need as the outcome variable. Results: There were no significant main effects of either type of medical mistrust on unmet medical care need. However, there was an interaction between the two types of medical mistrust, such that associations between each type of medical mistrust and unmet medical care needs were stronger at higher levels of the other type of medical mistrust. Racial/ethnic medical mistrust was associated with a greater likelihood of unmet medical needs at high, but not low, levels of LGBTQ+ medical mistrust. Conclusions: Racial/ethnic medical mistrust and LGBTQ+ medical mistrust exacerbate each other's influence on unmet medical care need. These results underscore the need for inclusive clinical practices for LGBTQ+ POC.

Young Men Who Have Sex With Men and Substance Use: A Comparison of Venue-Based Sampling and Geosocial Networking Application Sampling

To compare the demographics, sexual risk behaviors, and substance use characteristics of two probability samples of young men who have sex with men (YMSM): one recruited using a geosocial networking application (GSNA) and one recruited using venues. In 2017 and 2018, a cross-sectional online survey was utilized with a sample of 122 YMSM recruited in Los Angeles, CA. Recruitment procedures included both venue-based (n = 68) and GSNA-based probability sampling (n = 54). Sample substance use, sexual risk behaviors (e.g., unprotected sex at last encounter), and demographics were compared using chi-square tests and t-tests. The samples significantly differed in demographics characteristics (e.g., race, education, employment, outness). Samples did not significantly differ in sexual risk variables. Regressions indicated significant differences (higher in the venue sample) in substance use (marijuana, prescription drugs, alcohol, and poppers) between the two samples. Results indicate that recruitment method impacts demographics and substance use prevalence levels for YMSM. GSNA- based recruitment appears to recruit samples from a broader range of social demographics. GSNA-based methods may be especially applicable to areas in which venues are not readily accessible (e.g., rural areas), allowing social research with the most marginalized sexual minority populations.

Innovative Strategies for Remotely Sampling Hard-to-Reach Populations: Assessing Phone Versus Internet Respondent-Driven Sampling Approaches Among Venezuelan Refugees and Migrants in Colombia

It is challenging to quantitatively measure the health vulnerability and risk factors of refugees and migrants residing outside of formal settlement settings. For hard-to-reach populations without available sampling frames, researchers have increasingly turned to novel sampling and statistical methods, like respondent-driven sampling (RDS). "Standard" RDS is typically conducted face-to-face at fixed sites. However, during the coronavirus disease 2019 (COVID-19) pandemic, face-to-face survey methods and recruitment approaches posed high potential risk of virus transmission and infection, making remote RDS approaches optimal. In this paper, we explore the feasibility of implementing telephone and Internet RDS strategies to assess challenges faced by Venezuelan refugees and migrants in the city of Bogotá, Colombia's capital, and the department of Norte de Santander, the main Venezuelan-Colombian border crossing site. We describe RDS assumptions, survey design, formative research, and the implementation of both strategies and present diagnostics for determining whether assumptions are met. Phone-based recruitment strategies in both locations and the Internet strategy in Bogotá achieved their calculated sample size; however, the Internet strategy in Norte de Santander did not. Most RDS assumptions were sufficiently met at sites where sample sizes were reached. These surveys provide valuable lessons for implementing innovative remote strategies with which to study hard-to-reach populations such as refugees and migrants.

Examining differential success in recruitment using respondent driven sampling (RDS) in a multi-site study of gay, bisexual and other men who have sex with men

BACKGROUND

The Engage Study is a longitudinal biobehavioral cohort study of gay, bisexual and other men who have sex with men (GBM) in Toronto, Montreal, and Vancouver. Baseline data (2,449 participants) were collected from February 2017 - August 2019 using respondent-driven sampling (RDS). Recruitment in Montreal required fewer seeds, had a much shorter recruitment period, and recruited the largest sample.

METHODS

To better understand why RDS recruitment was more successful in Montreal compared to other sites, we conducted an analysis to examine RDS recruitment characteristics for GBM in each of the three study sites, explore demographic characteristics and measures of homophily, that is, the tendency of individuals to recruit other study participants who are like themselves, and compared motivations for study participation.

RESULTS

Montreal had the greatest proportion of participants over the age of 45 (29.1% in Montreal, 24.6% in Vancouver, and 21.0% in Toronto) and the highest homophily for this age group, but homophily was high across the three cities. Montreal also reported the lowest percentage of participants with an annual income greater or equal to $60,000 (7.9% in Montreal, 13.1% in Vancouver and 10.6% in Toronto), but homophily was similar across all three cities. The majority of participants indicated interest in sexual health and HIV as the main reason for participating (36.1% in Montreal, 34.7% in Vancouver, and 29.8% in Toronto). Financial interest as the main reason for participation was low (12.7% in Montreal, 10.6% in Vancouver, and 5.7% in Toronto).

CONCLUSION

Taken together, although we found some differences in study demographic characteristics and homophily scores, we were unable to fully explain the different recruitment success based on the data available. Our study underlines the fact that success of RDS implementation may vary by unknown factors, and that researchers should be proactive and flexible to account for variability.

Patterns of Event-Level Concurrent Substance Use During Sex Among Gay, Bisexual, and Other Men Who Have Sex with Men in Metro Vancouver

This study identified patterns of sexualized substance use among gay, bisexual, and other men who have sex with men (gbMSM) and examined associated risk factors for sexually transmitted and blood borne infections (STBBI). Data were from a longitudinal cohort recruited using respondent-driven sampling between Feb-2017 and Feb-2019. Participants reported on events with up to five of their most recent sexual partners. Latent class analysis examined patterns of concurrent substance use 2 h prior to or during sex. Multinomial regression identified demographic, partner-level, and event-level factors associated across 11,877 sexual events reported by 757 participants. Most combinations of substance use were rare, but most drugs were frequently combined with other drugs when they were used prior to or during a sexual event. Six latent classes of concurrent event-level substance use were identified. The referent class (58.8% of events) was characterized by limited use of any drugs. The Common Drug Use class (12.1%) was characterized by use of alcohol, cannabis, and poppers and the Licit Drug Use class (21.6%) was characterized by use of alcohol alone. The Party 'N' Play (PnP) class (2.3%) was characterized by use of crystal methamphetamine GHB, Poppers, and Erectile Drugs; The Multi-use (3.5%) class was characterized by the PnP substances plus alcohol and ecstasy; and the Cannabis + class was characterized by use of Cannabis, Erectile Drugs, and Ecstasy. Relative to the referent class, all other classes were associated with events with more behavioural and network risk factors for STBBIs-highlighting the need for harm reduction interventions for gbMSM who use these drugs.

Nominal Versus Realized Costs of Recruiting and Retaining a National Sample of Sexual Minority Adolescents in the United States: Longitudinal Study

BACKGROUND

Web-based recruitment for research studies is becoming increasingly popular and necessary. When compared with the traditional methods of recruitment, these methods may enable researchers to reach more diverse participants in less time. Social media use is highly prevalent among adolescents, and the unique context of social media may be particularly important for the recruitment of sexual minority young people who would not be captured by traditional methods.

OBJECTIVE

This paper described the details of a national web-based study recruitment approach aimed at sexual minority adolescents across the United States, focusing on important details of this relatively novel approach, including cost, time efficiency, and retention outcomes.

METHODS

This study recruited sexual minority adolescents aged 14-17 years living in the United States through targeted advertisements on Facebook, Instagram, and YouTube and through respondent-driven sampling (RDS). Potential participants completed eligibility screening surveys and were automatically directed to a baseline survey if they were eligible. After baseline survey completion, additional data checks were implemented, and the remaining participants were contacted for recruitment into a longitudinal study (surveys every 6 months for 3 years).

RESULTS

Recruitment lasted 44 weeks, and 9843 participants accessed the initial screening survey, with 2732 (27.76%) meeting the eligibility criteria and completing the baseline survey. Of those, 2558 (93.63%) were determined to have provided nonfraudulent, usable study data and 1076 (39.39%) subsequently enrolled in the longitudinal study. Of the baseline sample, 79.05% (2022/2558) was recruited through Facebook and Instagram, 3.05% (78/2558) through YouTube, and 17.9% (458/2558) through RDS. The average cost of recruiting a participant into the study was US $12.98, but the recruitment cost varied by method or platform, with a realized cost of US $13 per participant on Facebook and Instagram, US $24 on YouTube, and US $10 through RDS. Participant differences (sex assigned at birth, race and ethnicity, sexual orientation, region, and urbanicity) were identified between platforms and methods both in terms of overall number of participants and cost per participant. Facebook and Instagram were the most time efficient (approximately 15 days to recruit 100 participants), whereas RDS was the least time efficient (approximately 70 days to recruit 100 participants). Participants recruited through YouTube were the most likely to be longitudinally retained, followed by Facebook and Instagram, and then RDS.

CONCLUSIONS

Large differences exist in study recruitment cost and efficiency when using social media and RDS. Demographic, region, and urbanicity differences in recruitment methods highlight the need for attention to demographic diversity when planning and implementing recruitment across platforms. Finally, it is more cost-effective to retain than recruit samples, and this study provided evidence that with thorough screening and data quality practices, social media recruitment can result in diverse, highly involved study populations.

Improving web-based respondent-driven sampling performance among men who have sex with men in the Netherlands

Respondent-driven sampling (RDS) uses the social network of participants to sample people of populations that can be challenging to engage. While in this context RDS offers improvements on standard sampling methods, it does not always generate a sufficiently large sample. In this study we aimed to identify preferences of men who have sex with men (MSM) in the Netherlands regarding surveys and recruitment to studies with the subsequent goal of improving the performance of web-based RDS in MSM. A questionnaire about preferences with respect to various aspects of an web-based RDS study was circulated among participants of the Amsterdam Cohort Studies, a study among MSM. The duration of a survey and the type and amount of participation reward were explored. Participants were also asked about their preferences regarding invitation and recruitment methods. We used multi-level and rank-ordered logistic regression to analyze the data and identify the preferences. The majority of the 98 participants were older than 45 years (59.2%), were born in the Netherlands (84.7%), and had a university degree (77.6%). Participants did not have a preference regarding the type of participation reward, but they preferred to spend less time on a survey and to get a higher monetary reward. Sending a personal email was the preferred option to getting invited or inviting someone to a study, while using Facebook messenger was the least preferred option. There are differences between age groups: monetary rewards were less important to older participants (45+) and younger participants (18-34) more often preferred SMS/WhatsApp to recruit others. When designing a web-based RDS study for MSM, it is important to balance the duration of the survey and the monetary reward. If the study takes more of a participants time, it might be beneficial to provide a higher incentive. To optimize expected participation, the recruitment method should be selected based on the targeted population group.

Treatment interruptions and community connectedness among gbMSM living with HIV in Metro Vancouver, Canada

HIV treatment interruptions are a major public health concern that demonstrate a lack of engagement in care and is detrimental to the health of people living with HIV. Community connectedness have demonstrated a protective effect for psychosocial health but are not well understood for HIV treatment outcomes. We explored associations between community connectedness and treatment interruptions among gay, bisexual and other men who have sex with men (gbMSM) living with HIV in Vancouver, British Columbia. We analyzed survey data from the Momentum Health Study and identified treatment interruptions through data linkages with the provincial HIV Drug Treatment Program as episodes lasting more than 60 days beyond an expected antiretroviral therapy refill date from February 2012 to July 2019. We built a mixed-effects logistic regression model, adjusting for confounders. Of 213 gbMSM living with HIV, 54 experienced treatment interruption (25.4%) over a median five-year follow-up. Multivariable results found the number gbMSM who spoken to in the past month (aOR = 0.995; 95% CI = 0.991, 1.000 (per 100-unit increase)) and attending a gay community meeting more than once per month (aOR = 0.32; 95% CI = 0.11, 0.89) were associated with lower odds of treatment interruptions. These results highlight the importance of social connections in facilitating effective HIV care.

Undetectable or Unknown? A Longitudinal Event-Level Analysis of Disclosure of HIV Serostatus and Undetectability Among Gay, Bisexual, and Other Men Who have Sex with Men (gbMSM) in Metro Vancouver

We examined temporal trends and factors associated with reporting partner's serostatus and viral load among a sample of gay, bisexual and other men who have sex with men (gbMSM) in Vancouver, Canada. Participants were recruited using respondent-driven sampling and we collected prospective cohort data from 09/2014 to 02/2017 using a computer-assisted questionnaire and nurse-administered STI/HIV testing. Our study included 481 participants reporting on 3780 sexual events. Among HIV-negative/unknown gbMSM we found a trend towards decreased proportions of sexual events reporting an unknown HIV-status partner (42-19%; p =  < 0.001) and found increased proportions among gbMSM living with HIV (11-27%; p = 0.043). More participants living with HIV reported sex with undetectable partners, compared to HIV-negative/unknown participants (14.8% versus 5%). Our multivariable model found that compared with unknown status partners, undetectable partners were older, were from longer sexual relationships and were more likely to engage in condomless anal sex. Findings indicate that HIV-negative gbMSM seem more aware of the serostatus of their partners over time, but knowledge of partners' viral load over time was not significant. Further research should assess the degree to which new campaigns such as Undetectable = Untransmittable (U = U) are associated with discussions about HIV disclosure and viral load status.

Prevalence of HIV and sexually transmitted and blood-borne infections, and related preventive and risk behaviours, among gay, bisexual and other men who have sex with men in Montreal, Toronto and Vancouver: results from the Engage Study

Objectives

The last Canadian biobehavioural surveillance study of HIV and other sexually transmitted and blood-borne infections (STBBI) among gay, bisexual and other men who have sex with men (GBM) was conducted in 2010. We designed a study to measure STBBI prevalence among GBM in metropolitan Montreal, Toronto and Vancouver and to document related preventive and risk behaviours.

Methods

The Engage Cohort Study used respondent-driven sampling (RDS) to recruit GBM who reported sex with another man in the past 6 months. At baseline, we examined recruitment characteristics of the samples, and the RDS-II-adjusted distributions of socio-demographics, laboratory-confirmed HIV and other STBBI prevalence, and related behaviours, with a focus on univariate differences among cities.

Results

A total of 2449 GBM were recruited from February 2017 to August 2019. HIV prevalence was lower in Montreal (14.2%) than in Toronto (22.2%) or Vancouver (20.4%). History of syphilis infection was similar across cities (14–16%). Vancouver had more HIV-negative/unknown participants who reported never being HIV tested (18.6%) than Toronto (12.9%) or Montreal (11.5%). Both Montreal (74.9%) and Vancouver (78.8%) had higher proportions of men who tested for another STBBI in the past 6 months than Toronto (67.4%). Vancouver had a higher proportion of men who used pre-exposure prophylaxis (PrEP) in the past 6 months (18.9%) than Toronto (11.1%) or Montreal (9.6%).

Conclusion

The three largest cities of Canada differed in HIV prevalence, STBBI testing and PrEP use among GBM. Our findings also suggest the need for scale-up of both PrEP and STI testing among GBM in Canada.

Longitudinal Event-Level Sexual Risk and Substance Use among Gay, Bisexual, and Other Men Who Have Sex with Men

(1) Background: Condomless anal sex and substance use are associated with STI risk among gay, bisexual, and other men who have sex with men (gbMSM). Our first study objective was to describe event-level sexual risk and substance use trends among gbMSM. Our second study objective was to describe substances associated with event-level sexual risk. (2) Methods: Data come from the Momentum Health Study in Vancouver, British Columbia and participants were recruited from 2012-2015, with follow-up until 2018. Stratified by self-reported HIV status, we used generalized estimating equations to assess trends of sexual event-level substance use and assessed interactions between substance use and time period on event-level higher risk sex defined as condomless anal sex with an HIV serodifferent or unknown status partner. (3) Results: Event-level higher risk anal sex increased across the study period among HIV-negative/unknown (baseline prevalence: 13% vs. study end prevalence: 29%) and HIV-positive gbMSM (baseline prevalence: 16% vs. study end prevalence: 38%). Among HIV-negative/unknown gbMSM, event-level erectile drug use increased, while alcohol use decreased over the study period. Overall, interactions between substance use and time on higher risk anal sex were not statistically significant, regardless of serostatus. However, we found a number of time-specific significant interactions for erectile drugs, poppers, Gamma-hydroxybutyrate (GHB), crystal methamphetamine and ecstasy/MDMA use among HIV-negative/unknown gbMSM. (4) Conclusion: Significant differences in substance use trends and associated risks exist and are varied among gbMSM by serostatus. These findings provide a more comprehensive understanding of the effects of event-level substance use on sexual risk through longitudinal follow-up of nearly six years.

Telephone peer recruitment and interviewing during a respondent-driven sampling (RDS) survey: feasibility and field experience from the first phone-based RDS survey among men who have sex with men in Côte d'Ivoire

Background

Many respondent-driven sampling (RDS) methodologies have been employed to investigate hard-to-reach populations; however, these methodologies present some limits. We describe a minimally investigated RDS methodology in which peer recruitment and interviewing are phone-based. The feasibility of the methodology, field experiences, validity of RDS assumptions and characteristics of the sample obtained are discussed.

Methods

We conducted a phone-based RDS survey among men who have sex with men (MSM) aged 18 or above and living in Côte d’Ivoire. Eight initial MSM across Côte d’Ivoire were selected. Participants were asked to call a hotline to be registered and interviewed by phone. After the participants completed the questionnaire, they were asked to recruit a maximum of 3 MSM from their acquaintances.

Results

During the 9 months of the survey, 576 individuals called the hotline, and 518 MSM completed the questionnaire. The median delay between the invitation to participate and the completion of the questionnaire by peer-recruited MSM was 4 days [IQR: 1–12]. The recruitment process was not constant, with high variation in the number of people who called the hotline during the survey period.

RDS chain convergence to equilibrium was reached within 6 waves for most of the selected variables. For the network size estimation assumption, participants who incorrectly estimated their network size were observed.

Regarding the sample obtained, MSM were recruited from all the regions of Côte d’Ivoire with frequent interregional recruitment; 23.5% of MSM were recruited by someone who does not live in the same region. Compared to the MSM who participated in two other surveys in Côte d’Ivoire, the MSM in our sample were less likely to know about an MSM non-governmental organisation. However, MSM aged 30 years old and above and those with a low level of education were underrepresented in our sample.

Conclusion

We show that phone-based RDS surveys among MSM are feasible in the context of sub-Saharan Africa. Compared to other classical RDS survey methodologies, the phone-based RDS methodology seems to reduce selection bias based on geography and proximity with the MSM community. However, similar to other methodologies, phone-based RDS fails to reach older and less-educated MSM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-021-01208-x.

The CAN-DO-IT Model: a Process for Developing and Refining Online Recruitment in HIV/AIDS and Sexual Health Research

PURPOSE OF REVIEW

HIV/AIDS and sexual health research has increasingly relied on online recruitment in recent years. However, as potential online recruitment avenues (e.g., dating and sexual networking applications, websites, social media) have proliferated, navigating this process has become increasingly complex. This paper presents a practical model to guide researchers through online recruitment irrespective of platform.

RECENT FINDINGS

The CAN-DO-IT model reflects 7 iterative steps based on work by the authors and other investigators: conceptualize scope of recruitment campaign, acquire necessary expertise, navigate online platforms, develop advertisements, optimize recruitment-to-enrollment workflow, implement advertising campaign, and track performance of campaigns and respond accordingly. Online recruitment can accelerate HIV/AIDS research, yet relatively limited guidance exists to facilitate this process across platforms. The CAN-DO-IT model presents one approach to demystify online recruitment and reduce enrollment barriers.

Loneliness and self-rated physical health among gay, bisexual and other men who have sex with men in Vancouver, Canada

BACKGROUND

Due to stigma and discrimination, gay, bisexual and other men who have sex with men (gbMSM) potentially carry a heightened burden of loneliness. This analysis investigates loneliness among gbMSM and its relationship with self-rated physical health, along with the mediating effect of depression.

METHODS

Participants were recruited using respondent-driven sampling into the Momentum Health Study (February 2012-February 2015) with follow-up visits occurring every 6 months till February 2018. Using computer-assisted self-interviews, measures of loneliness were assessed using a 6-item Loneliness Scale for Emotional and Social Loneliness (lonely vs not lonely). Current physical health was self-assessed (poor, fair, good, very good or excellent). A multivariable generalised linear-mixed model with a logit link function was used to examine the relationship between loneliness and self-rated physical health. We further investigated the mediating effect of depressive symptomatology on this relationship via the Hospital Anxiety and Depression Scale.

RESULTS

Of the 770 participants included, we found that 61% (n=471) experienced loneliness at baseline. Of the 674 (88%) who reported good/very good/excellent physical health, 59% (n=391) reported loneliness, compared with 87% (n=80) of those in poor/fair self-rated physical health who reported feeling lonely. After adjustment for confounding, loneliness was associated with poor self-rated physical health (adjusted OR 1.71; 95% CI 1.13 to 2.60). Depressive symptomatology was found to partially mediate this relationship.

CONCLUSION

There may be a need for the integration of social, mental and physical health programming, targeted towards gbMSM, to alleviate the degree of loneliness experienced and its co-occurrence with poor self-rated physical health.

Agreement between gay, bisexual and other men who have sex with men's period prevalence and event-level recall of sexual behaviour: an observational respondent-driven sampling study

Background Agreement between sexual behaviour recall measures among gay, bisexual and other men who have sex with men (GBM) in Vancouver, Canada was examined.

METHODS

Study participants were sexually active GBM aged ≥16 years recruited via respondent-driving sampling (RDS). Participants completed a computer-assisted self-interview survey, including individual-level period prevalence (last 6 months) and sexual event-level (last sex with each of the five most recent partners) measures. RDS-weighted kappa statistics assessed the agreement between these types of data across five different sexual risk outcomes, stratified by self-identified HIV status and other demographic factors (age, education, race/ethnicity).

RESULTS

Of 719 participants, 195 (RDS-weighted 23.4%) were HIV-positive. For HIV-negative GBM (n=524, RDS-weighted 76.6%), there were moderate agreements between period prevalence and event-level data for any anal intercourse (AI), any condomless AI and any fisting, but weak agreement for any discordant/unknown AI and any sex toy use. For HIV-positive GBM, there was moderate agreement for any AI, any condomless AI, any discordant/unknown AI and any fisting; there was weak agreement for any sex toy use. Agreement between measurement types was generally higher for GBM who were living with HIV, who were older and who completed secondary school; there was little difference in agreement levels by race/ethnicity.

CONCLUSIONS

We observed moderate agreement between sexual behaviour recall through event-level and period prevalence questions. Each method had differential advantages and ideal circumstances for use, which should be guided by one's research question and outcome measure of interest.

Google AdWords and Facebook Ads for Recruitment of Pregnant Women into a Prospective Cohort Study With Long-Term Follow-Up

Objectives Several types of epidemiologic studies suffer from decreasing participation rates, resulting in potential selection bias and delay or termination of studies. We aimed to determine the feasibility of online methods for recruitment of pregnant women into a prospective cohort study. Methods In addition to traditional recruitment through prenatal care providers, we advertized participation in the PRegnancy and Infant DEvelopment (PRIDE) Study, an ongoing prospective cohort study with long-term follow-up in The Netherlands enrolling women in early pregnancy, through Google AdWords (30 days) and Facebook Ads (31 and 27 days) campaigns between September 2016 and January 2017. We calculated costs per eligible participant and compared demographics, health-related characteristics, and follow-up rates between participants recruited through online methods and prenatal care providers. Results During the study period, we recruited six women through AdWords (€54.28 per participant), 59 through Facebook (€10.17 per participant), and 327 through prenatal care providers (no valid cost estimate available). Facebook participants seemed to be younger (29.0 vs. 30.7 years), to have a higher body mass-index and/or low/intermediate education (27.0 vs. 24.0 kg/m² and 41 vs. 25%, respectively), and to start prenatal care in secondary care more often (12 vs. 5%) than participants recruited through prenatal care providers. Item non-response and loss to follow-up rates were higher among women recruited online than among those recruited through prenatal care providers. Conclusion Google AdWords did not contribute substantially, but Facebook Ads may complement traditional recruitment methods of pregnant women into prospective cohort studies, despite challenges that may threaten internal validity.

Crystal Methamphetamine Use and Initiation among Gay, Bisexual, and Other Men Who Have Sex with Men Living with HIV in a Treatment as Prevention Environment

Risk compensation in an HIV Treatment as Prevention (TasP) environment may increase high-risk sexual and substance use behaviors among people living with HIV. Objective: To examine recent crystal methamphetamine (CM) use/initiation in a longitudinal cohort of gay, bisexual, and other men who have sex with men (GBMSM) living with HIV in Metro Vancouver, Canada. Methods: Eligible participants were GBMSM aged >15 years who reported sex with another man in the past six months. Participants were recruited using respondent-driven sampling and self-completed a computer questionnaire every six months. We used multi-level generalized mixed-effect models to evaluate trends in recent CM use (past six months), multivariable logistic regression to identify covariates of recent CM use, and multivariable survival analysis to identify predictors of CM initiation. Results: Of 207 GBMSM living with HIV at enrollment, 44.3% reported recent CM use; there was a statistically non-significant decrease over the study period (41% in first period to 25% in final period, p = 0.087). HIV treatment optimism was not associated with CM use/initiation. CM use was positively associated with depressive symptomology, sexual escape motivation, transactional sex, number of anal sex partners, condomless anal sex with seroconcordant partners, STIs, and other substance use. Recent CM use was negatively associated with viral load sorting. CM initiation was predicted by escape motivation, transactional sex, and group sex participation. Conclusion: Results suggest that CM use among GBMSM living with HIV is prevalent and increased CM use/initiation is not a consequence of TasP public policy.

Generational differences in sexual behaviour and partnering among gay, bisexual, and other men who have sex with men

INTRODUCTION

Given that different generations of gay, bisexual, and other men who have sex with men (gbMSM) have been influenced by substantially different life course events and cultural contexts, we explored differences in sexual behaviour between millennials, Gen-Xers, and baby boomers.

METHODS

Sexually active gbMSM from Metro Vancouver, ≥16 years, were recruited using respondent-driven sampling between 2012-2015 and completed computer-assisted self-interviews every 6 months, up to 2017. To explore differences between generations (millennials born ≥1987, Gen-Xers born 1962-1986, baby boomers born <1962) we used multivariable logistic regression models using baseline, RDS-weighted data. We also examined 6-month trends, stratified by generation, in partner number, prevalence of high-risk sex, and relationship status using hierarchical mixed-effects models.

RESULTS

Among 774 gbMSM (190 millennials, 469 Gen-Xers, 115 baby boomers), median age of first anal sex with a male partner decreased from 20 (aQ1,aQ3:17,25) among baby boomers to 18 (aQ1,aQ3: 16,20) among millennials (x ² (DF=2, N=764)=12.920, p=0.002). After controlling for relevant demographics, differences were observed for some sexual behaviours (i.e., anal sex positioning, giving oral sex, sex toys, masturbation, sexual app/website use, transactional sex) but not others (i.e., receiving oral sex, rimming, fisting, watersports, group sex). At baseline, millennials reported less high-risk sex than other generations but all trended toward less high-risk sex, fewer partners, and regular partnering over the course of the study.

CONCLUSIONS

While there was notable similarity across generations, millennial gbMSM reported earlier age at first anal intercourse and less high-risk sex. However, all generations trended towards less high-risk sex, fewer partners, and regular partnering over time.

Exploring the role of sex-seeking apps and websites in the social and sexual lives of gay, bisexual and other men who have sex with men: a cross-sectional study

Background The objective of this study was to explore the relationship between online sex-seeking, community/social attachment and sexual behaviour.

METHODS

Respondent-driven sampling was used to recruit 774 sexually active gay and bisexual men in Vancouver, Canada, aged ≥16 years. Multivariable logistic regression compared men who had used online sex-seeking apps/websites in the past 6 months (n=586) with those who did not (n=188).

RESULTS

Multivariable results showed that online sex seekers were more likely to be younger [adjusted odds ratio (aOR)=0.95, 95% CI: (0.93-0.96)], college educated [aOR=1.60, 95% CI: (1.07, 2.40)], have more Facebook friends [aOR=1.07, 95% CI: (1.01, 1.13)], spend more social time with other gay men [aOR=1.99, 95% CI: (1.33-2.97)], and were less likely to identify emotionally with the gay community [aOR=0.93, 95% CI: (0.86-1.00)]. Further, they had displayed high sensation-seeking behaviour [aOR=1.08, 95% CI: (1.03-1.13)], were more likely to engage in serodiscordant/unknown condomless anal sex [aOR=2.34, 95% CI: (1.50-3.66)], use strategic positioning [aOR=1.72, 95% CI: (1.08-2.74)], ask their partner's HIV-status prior to sex [aOR=2.06, 95% CI: (1.27-3.37)], and have ever been tested for HIV [aOR=4.11, 95% CI: (2.04-8.29)].

CONCLUSION

These findings highlight the online and offline social behaviour exhibited by gay and bisexual men, pressing the need for pro-social interventions to promote safe-sex norms online. We conclude that both Internet and community-based prevention will help reach app/web users.

Methodological Considerations for Advancing Research on the Health and Wellbeing of Sexual and Gender Minority Youth

Continued research with sexual and gender minority (SGM) youth is essential both to understand health disparities and to develop interventions targeting those disparities, but conducting rigorous, ethical research with these populations remains a substantial challenge. In addition to considerations for research with adolescents in general, such as utilizing developmentally appropriate measures and obtaining parental permission, factors unique to SGM youth must be addressed at every step of the research process. Defining the study population is complex, as is recruiting a sample once it is defined. Measurement is another challenge, given the paucity of measures developed for or validated with SGM samples. Key constructs, such as sexual orientation, gender identity, and family acceptance, are not amenable to randomization and involving minor participants' parents poses ethical concerns given the precarious home and safety situations that can arise from employing typical study procedures with youth who have a stigmatized identity. In this article, we examine some of these unique methodological challenges. Informed by theoretical and empirical literature, practical experience, and an ongoing dialogue with SGM youth themselves, we present a guide to best practices for ethical, productive research with SGM youth. By discussing existing approaches to studying SGM youth and suggesting innovative ways to approach the questions that remain, we hope to assist the research community in addressing methodological gaps to advance research on SGM youth in relation to families and schools.

HIV leadership programming attendance is associated with PrEP and PEP awareness among young, gay, bisexual, and other men who have sex with men in Vancouver, Canada

BACKGROUND

Young gay, bisexual, and other men who have sex with men (YGBM) may have reduced engagement and knowledge of HIV care and biomedical HIV prevention strategies, such as pre-exposure prophylaxis (PrEP), post-exposure prophylaxis (PEP), and Treatment as Prevention (TasP), compared with adult GBM. We sought to understand differences in HIV prevention awareness, health care access, and service utilization between youth (16-29 years) and adult (≥30 year) GBM, as well as factors associated with attendance in HIV leadership programming among YGBM living in the publicly funded PrEP setting of Vancouver, Canada.

METHODS

Sexually-active GBM were recruited using respondent-driven sampling (RDS) from February 2012 to February 2015. Participants completed an in-person computer-assisted self-interview every 6 months, up to February 2017, with questions on sociodemographic factors, awareness of biomedical HIV prevention strategies, and an HIV treatment optimism-skepticism scale. Participants were asked if they had ever attended either of two HIV-leadership programs designed for YGBM. Both programs involve multiple GBM-led education and social networking sessions operated by community-based organizations in Vancouver. Multivariable Glimmix confounder models assessed differences between youth and adult GBM. Among younger men, bivariate analyses examined factors associated with HIV-leadership program attendance.

RESULTS

Of 698 GBM who enrolled in the longitudinal study, 36.8% were less than 30 years old at the first study visit. After controlling for gender identification, sexual orientation, HIV status, and income in the past 6 months, younger GBM (n = 257/698) had lower awareness of biomedical HIV prevention strategies and less HIV treatment optimism compared with older GBM (n = 441/698). Among younger GBM who attended HIV-leadership programs (n = 50), greater awareness of biomedical HIV prevention strategies and higher HIV treatment optimism were reported, compared with non-attendees.

CONCLUSION

Younger GBM, who are disproportionately affected by the HIV epidemic, are less aware of new prevention technologies than older GBM, but attending peer-based HIV-leadership programs ameliorates age-disparities in HIV-prevention knowledge and treatment optimism.

A latent class analysis of substance use and culture among gay, bisexual and other men who have sex with men

Assessments of gay and bisexual men's substance use often obscures salient sociocultural and identity-related experiences related to how they use drugs. Latent class analysis was used to examine how patterns of substance use represent the social, economic and identity-related experiences of this population. Participants were sexually active gay and bisexual men (including other men who have sex with men), aged ≥ 16 years, living in Metro Vancouver (n = 774). LCA indicators included all substances used in the past six months self-reported by more than 30 men. Model selection was made with consideration to model parsimony, interpretability and optimisation of statistical criteria. Multinomial regression identified factors associated with class membership. A six-class solution was identified representing: 'assorted drug use' (4.5%); 'club drug use' (9.5%); 'street drug use' (12.1%); 'sex drug use' (11.4%); 'conventional drug use' (i.e. tobacco, alcohol, marijuana; 25.9%); and 'limited drug use' (36.7%). Factors associated with class membership included age, sexual orientation, annual income, occupation, income from drug sales, housing stability, group sex event participation, gay bars/clubs attendance, sensation seeking and escape motivation. These results highlight the need for programmes and policies that seek to lessen social disparities and account for social distinctions among this population.

Trends in Awareness and Use of HIV PrEP Among Gay, Bisexual, and Other Men who have Sex with Men in Vancouver, Canada 2012-2016

Gay, bisexual, and other men who have sex with men (gbMSM) are at the highest risk for HIV infection in British Columbia (BC). Pre-exposure prophylaxis (PrEP) has been recently licensed but is currently not publicly funded in BC. Using respondent-driven sampling, we recruited a cohort of gbMSM to complete a computer-assisted self-interview with follow-up every 6 months. Stratified by HIV status, we examined trends in awareness of PrEP from 11/2012 to 02/2016 and factors associated with PrEP awareness. 732 participants responded to the PrEP awareness question. Awareness of PrEP among HIV-negative men increased from 18 to 80% (p < 0.0001 for trend); among HIV-positive men, awareness increased from 36 to 77% (p < 0.0001). PrEP awareness was associated with factors related to HIV risk including sero-adaptive strategies and sexual sensation seeking. Eight HIV-negative men reported using PrEP. Low PrEP uptake highlights that PrEP access should be expanded for at-risk gbMSM in BC.

Assessing the longitudinal stability of latent classes of substance use among gay, bisexual, and other men who have sex with men

BACKGROUND

Association between substance use and HIV-risk among gay and bisexual men (GBM) is well documented. However, their substance use patterns are diverse, and it is unknown whether self-reported use patterns are stable over time.

METHODS

Sexually-active GBM, aged >16 years, were recruited in Metro Vancouver using respondent-driven sampling and followed across 5 study visits at six-month intervals (n = 449). To identify distinct patterns of substance use and their longitudinal stability, Latent Transition Analysis (LTA) was conducted for drugs reported by at least 30 participants. Intraclass correlation coefficients (ICC) quantified the stability of class assignments.

RESULTS

Six classes characterizing 'limited drug use' (i.e., low use of all drugs, except alcohol), 'conventional drug use' (i.e., use of alcohol, marijuana, and tobacco), 'club drug use' (i.e., use of alcohol, cocaine, and psychedelics), 'sex drug use' (i.e., use of alcohol, crystal meth, GHB, poppers, and erectile dysfunction drugs), 'street drug use' (i.e., use of alcohol and street opioids) and 'assorted drug use' (i.e., use of most drugs) were identified. Across five visits (2.5 years), 26.3% (n = 118/449) of GBM transitioned between classes. The prevalence of limited use trended upwards (Baseline:24.5%, Visit 5:28.3%, p < 0.0001) and assorted use trended downwards (13.4%-9.6%, p = 0.001). All classes had strong longitudinal stability (ICC > 0.97).

CONCLUSION

The stability of latent substance use patterns highlight the utility of these measures in identifying patterns of substance use among people who use drugs - potentially allowing for better assessment of these groups and interventions related to their health.

Patterns of Online and Offline Connectedness Among Gay, Bisexual, and Other Men Who Have Sex with Men

This study examined patterns of connectedness among 774 sexually-active gay, bisexual, and other men who have sex with men (GBM), aged ≥ 16 years, recruited using respondent-driven sampling in Metro Vancouver. Latent class analysis examined patterns of connectedness including: attendance at gay venues/events (i.e., bars/clubs, community groups, pride parades), social time spent with GBM, use of online social and sex seeking apps/websites, and consumption of gay media. Multinomial regression identified correlates of class membership. A three-class LCA solution was specified: Class 1 "Socialites" (38.8%) were highly connected across all indicators. Class 2 "Traditionalists" (25.7%) were moderately connected, with little app/website-use. Class 3 "Techies" (35.4%) had high online connectedness and relatively lower in-person connectedness. In multivariable modelling, Socialites had higher collectivism than Traditionalists, who had higher collectivism than Techies. Socialites also had higher annual incomes than other classes. Techies were more likely than Traditionalists to report recent serodiscordant or unknown condomless anal sex and HIV risk management practices (e.g., ask their partner's HIV status, get tested for HIV). Traditionalists on the other hand were less likely to practice HIV risk management and had lower HIV/AIDS stigma scores than Socialites. Further, Traditionalists were older, more likely to be partnered, and reported fewer male sex partners than men in other groups. These findings highlight how patterns of connectedness relate to GBM's risk management.

The additive effects of depressive symptoms and polysubstance use on HIV risk among gay, bisexual, and other men who have sex with men

INTRODUCTION

Among gay, bisexual, and other men who have sex with men (GBM), collinearity between polysubstance use and mental health concerns has obscured their combined effects on HIV risk with multivariable results often highlighting only one or the other.

METHODS

We used mediation and moderation analyses to examine the effects of polysubstance use and depressive symptoms on high-risk sex (i.e., condomless anal sex with serodiscordant/unknown status partner) in a sample of sexually-active GBM, aged ≥16 years, recruited in Metro Vancouver using respondent driven sampling. Hospital Anxiety and Depression Scale scores assessed mental health. Alcohol Use Disorder Identification Test scores assessed alcohol disorders. Poly-use of multiple drug types (e.g., stimulants, sedatives, opiates, hallucinogens) was assessed over the previous six months.

RESULTS

Among 719 predominantly white (68.0%), gay-identified (80.7%) GBM, alcohol use was not associated with increased prevalence of high-risk sex. Controlling for demographic factors and partner number, an interaction between polysubstance use and depressive symptoms revealed that the combined effects were additively associated with increased odds for high-risk sex. Mediation models showed that polysubstance use partially mediated the relationship between depressive symptoms and high-risk sex.

CONCLUSION

An interaction effect between polysubstance use (defined by using 3 or more substances in the past six months) and depressive symptoms (defined by HADS scores) revealed that the combination of these factors was associated with increased risk for high-risk sex - supporting a syndemic understanding of the production of HIV risk.

HIV treatment optimism and crystal methamphetamine use and initiation among HIV-negative men who have sex with men in Vancouver, Canada: A longitudinal analysis

BACKGROUND

Treatment as Prevention (TasP) leading to increased HIV treatment optimism among men who have sex with men (MSM) has been previously associated with behavioural risk compensation, though not yet via crystal methamphetamine (CM) use. Among HIV-negative MSM in a TasP environment, this study aimed to investigate the prevalence of recent CM use over time, examine the association between HIV treatment optimism and CM use and initiation, and identify correlates of recent CM use and predictors of CM initiation.

METHODS

Using data from a prospective behavioural cohort study of sexually active MSM in the Vancouver area, we used multi-level generalized mixed effect models to evaluate temporal trends in CM use, univariable and multivariable logistic regression to identify covariates of recent CM use, and univariable and multivariable survival analysis to identify predictors of CM initiation.

RESULTS

Of 497 HIV-negative cohort participants, 10.3% reported any recent CM use at enrollment. From 2012-2016, there were no statistically significant temporal trends in overall CM use or with routes of administration. In multivariable logistic regression analyses, HIV treatment optimism was not associated with recent CM use (not retained in final model) or CM initiation (aHR = 1.06, 95% CI:0.98-1.15). Significant correlates of CM use include recent gamma-hydroxybutyrate (GHB) and ecstasy use, and having received/given drugs for sex.

CONCLUSIONS

Among HIV-negative MSM in Vancouver, HIV treatment optimism does not appear to be independently associated with CM use or initiation of use, though use of CM was both prevalent and stable over time.

Multiple strategies to identify HIV-positive black men who have sex with men and transgender women in New York City: a cross-sectional analysis of recruitment results

INTRODUCTION

Black men who have sex with men and transgender women are at high risk for HIV infection, but are more likely to be unaware of their infection or not in care for diagnosed HIV compared to other races. Respondent driven sampling has been advanced as a method to reach stigmatized and hidden populations for HIV testing. We compared strategies to recruit black, substance-using men who have sex with men and transgender women to identify newly diagnosed HIV infection, or those previously diagnosed but not in care.

METHODS

The STAR (Seek, Test, and Retain) study (ClinicalTrials.gov NCT01790360) used several recruitment strategies to identify black, substance-using men who have sex with men and transgender women with undiagnosed HIV infection or with previously diagnosed HIV infection but who were not in HIV care. Respondent-driven sampling, community-based recruitment and online advertising were used to recruit participants. Incentivized peer referral was integrated into all recruitment strategies. Participants completed interviewer-administered questionnaires and HIV testing. Demographic and HIV risk-related characteristics and recruitment strategy were summarized and stratified by HIV status. Associations were tested using Pearson's chi-squared, Fisher's exact, and Wilcoxon rank sum tests. Factors associated with HIV-positive diagnosis at p < 0.1 were included in a multivariable logistic regression model.

RESULTS

From July 2012 through October 2015, the study enrolled 1929 participants; 96.3% men who have sex with men and 3.7% transgender women. Behavioural risk factors included recent condomless anal sex (55.6%) and recent substance use during sex (73.1%). HIV prevalence was 8.7%. In multivariable analysis, significant associations with HIV infection included being transgender; non-Hispanic black; gay/homosexual orientation; not homeless; and less likely to have insufficient income for necessities. Among recruitment strategies, respondent driven sampling was least effective in identifying HIV-positive participants.

CONCLUSIONS

Integrating multiple recruitment strategies yielded a large sample of black men who have sex with men and transgender women at substantial risk for HIV. Respondent-driven sampling was less effective than other strategies at identifying men who have sex with men and transgender women with HIV.

An Event-Level Analysis of Condom Use During Anal Intercourse Among Self-Reported Human Immunodeficiency Virus-Negative Gay and Bisexual Men in a Treatment as Prevention Environment

BACKGROUND

We sought to identify factors associated with condom use during anal intercourse among self-identified human immunodeficiency virus-negative gay, bisexual, and other men who have sex with men (GBM) in Vancouver, Canada following "treatment as prevention" (TasP) scale-up in 2010.

METHODS

Sexually active GBM were recruited using respondent-driven sampling from 2012 to 2014. We analyzed participants' most recent sexual encounter with up to their last 5 sexual partners within the past 6 months. In addition to individual- and event-level explanatory factors, we assessed potential associations with TasP awareness, TasP-related prevention practice (viral load sorting), and TasP-related attitudes (human immunodeficiency virus treatment optimism). Accounting for clustering at the respondent-driven sampling chain-level and participant-level, factors associated with event-level condom use versus nonuse were determined using a multivariable generalized linear mixed model built using backward selection and AIC minimization.

RESULTS

Of 513 participants, 436 GBM (85%) reported a total of 1196 anal sex events with 56% condom use. The proportion of condom-protected sexual events decreased monthly over the study period (odds ratio [OR], 0.95 per month, 95% confidence interval [CI], 0.92-0.98). The TasP practices and attitudes were significantly associated with lower odds of condom use at the univariate level, but were no longer significant at multivariate level. In the multivariable model, event-level partner methamphetamine use (adjusted OR [aOR], 0.18; 95% CI, 0.06-0.58), frequency of recent anal intercourse with that partner (aOR, 0.97 per act; 95% CI, 0.95-0.98) and time since first sex with that partner (aOR, 0.97 per 6 months; 95% CI, 0.95-0.99) were associated with lower odds of condom use, whereas event-level participant alcohol use (aOR, 1.41; 95% CI, 1.01-1.98) and no planned future sex with that partner (aOR, 1.56; 95% CI, 1.08-2.27) were associated with greater odds of condom use. Event-level receptive-only (aOR, 2.10; 95% CI, 1.38-3.20) or insertive-only (aOR, 2.53; 95% CI, 1.64-3.90) sexual positions were associated with greater odds of condom use compared with reporting both positions.

CONCLUSIONS

The TasP-related factors were not the most salient predictors of GBM's condom use. Health promotion must consider associations between condomless anal sex and substance use and relational factors.

Belief in Treatment as Prevention and Its Relationship to HIV Status and Behavioral Risk

BACKGROUND

We evaluated attitudes toward treatment as prevention (TasP) among gay, bisexual, and other men who have sex with men (GBM) in Vancouver, Canada.

METHODS

Sexually active GBM, aged ≥16 years, were recruited between 2012 and 2015 using respondent-driven sampling. At each 6-month follow-up, participants completed a computer-administered questionnaire and nursing visit. Repeated-measures latent class analysis, grouped by self-reported serostatus, identified patterns of TasP endorsement by considering TasP-related awareness, attitudes, and behavior. Binary logistic regression identified covariates of class membership. Bivariate interactions with visit number identified factors associated with longitudinal changes in class membership.

RESULTS

A total of 774 men provided 2590 observations. Of these, 698 enrolled in the cohort, 575 had at least 1 follow-up visit. Among these, the median follow-up time was 1.98 years (Q1-Q2: 1.49-2.49 years). Repeated-measures latent class analysis identified 3 classes: "unaware" (64.2% HIV negative/unknown vs. 29.2% of HIV positive), "skeptical" (29.7% vs. 23.1%), and "believing" (6.1% vs. 47.7%). Membership in classes representing higher TasP endorsement was associated with greater odds of condomless anal sex and having more sexual partners. Age, sexual orientation, ethnicity, substance use, and social time spent with other GBM were also associated with class membership. Longitudinally, class membership was stable among HIV-positive men but shifted toward greater TasP endorsement among HIV-negative/unknown men. For HIV-negative/unknown men, increasing endorsement was positively associated with greater education, being employed, being in a relationship, and substance use and inversely associated with recent serodiscordant condomless anal sex or sexually transmitted infection diagnosis.

CONCLUSIONS

Over time, disparities in TasP diffusion by HIV status have lessened, although continue to persist across other key social strata.

Seroadaptive Strategies of Vancouver Gay and Bisexual Men in a Treatment as Prevention Environment

British Columbia's treatment as prevention policy has provided free access to highly active antiretroviral therapy (HAART) to all HIV-positive provincial residents since 1996. One outcome is an increase in HIV-positive gay and bisexual men (GBM) with suppressed viral loads. Previous cross-sectional analyses indicated that some Vancouver GBM now recognize condomless anal sex with men on HAART who report a suppressed viral load as a seroadaptive strategy. To test the hypothesis that this new strategy, termed viral load sorting (VLS), is recognized and used among by GBM in the Momentum Health Study, we analyzed longitudinal data for HIV-negative/unknown (n = 556) and HIV-positive (n = 218) serostatus participants. Analyses indicated that both groups reported VLS, and that serostatus and Treatment Optimism Scale scores were significant determinants in frequency and use. Results exemplify the medicalization of sex and Rogers' Diffusion Of Preventative Innovations Model, and they have important implications for HIV research and GBM sexual decision-making.

Lifetime Doctor-Diagnosed Mental Health Conditions and Current Substance Use Among Gay and Bisexual Men Living in Vancouver, Canada

BACKGROUND

Studies have found that gay, bisexual, and other men who have sex with men (GBM) have higher rates of mental health conditions and substance use than heterosexual men, but are limited by issues of representativeness.

OBJECTIVES

To determine the prevalence and correlates of mental health disorders among GBM in Metro Vancouver, Canada.

METHODS

From 2012 to 2014, the Momentum Health Study recruited GBM (≥16 years) via respondent-driven sampling (RDS) to estimate population parameters. Computer-assisted self-interviews (CASI) collected demographic, psychosocial, and behavioral information, while nurse-administered structured interviews asked about mental health diagnoses and treatment. Multivariate logistic regression using manual backward selection was used to identify covariates for any lifetime doctor diagnosed: (1) alcohol/substance use disorder and (2) any other mental health disorder.

RESULTS

Of 719 participants, 17.4% reported a substance use disorder and 35.2% reported any other mental health disorder; 24.0% of all GBM were currently receiving treatment. A lifetime substance use disorder diagnosis was negatively associated with being a student (AOR = 0.52, 95% CI [confidence interval]: 0.27-0.99) and an annual income ≥$30,000 CAD (AOR = 0.38, 95% CI: 0.21-0.67) and positively associated with HIV-positive serostatus (AOR = 2.54, 95% CI: 1.63-3.96), recent crystal methamphetamine use (AOR = 2.73, 95% CI: 1.69-4.40) and recent heroin use (AOR = 5.59, 95% CI: 2.39-13.12). Any other lifetime mental health disorder diagnosis was negatively associated with self-identifying as Latin American (AOR = 0.25, 95% CI: 0.08-0.81), being a refugee or visa holder (AOR = 0.18, 95% CI: 0.05-0.65), and living outside Vancouver (AOR = 0.52, 95% CI: 0.33-0.82), and positively associated with abnormal anxiety symptomology scores (AOR = 3.05, 95% CI: 2.06-4.51).

CONCLUSIONS

Mental health conditions and substance use, which have important implications for clinical and public health practice, were highly prevalent and co-occurring.

Seroadaptive Strategies of Gay & Bisexual Men (GBM) with the Highest Quartile Number of Sexual Partners in Vancouver, Canada

Despite continued research among men with more sexual partners, little information exists on their seroadaptive behavior. Therefore, we examined seroadaptive anal sex strategies among 719 Vancouver gay and bisexual men (GBM) recruited using respondent-driven sampling. We provide descriptive, bivariable, and multivariable adjusted statistics, stratified by HIV status, for the covariates of having ≥7 male anal sex partners in the past 6 months (Population fourth quartile versus <7). Sensitivity Analysis were also performed to assess the robustness of this cut-off. Results suggest that GBM with more sexual partners are more likely to employ seroadaptive strategies than men with fewer partners. These strategies may be used in hopes of offsetting risk, assessing needs for subsequent HIV testing, and balancing personal health with sexual intimacy. Further research is needed to determine the efficacy of these strategies, assess how GBM perceive their efficacy, and understand the social and health impacts of their widespread uptake.

An Event-Level Analysis of the Interpersonal Factors Associated With Condomless Anal Sex Among Gay, Bisexual, and Other Men Who Have Sex With Men (MSM) With Online-Met Partners

The interpersonal determinants of condomless anal sex (CAS) within online-initiated sexual relationships remain poorly understood. Therefore, respondent-driven sampling was used to recruit a prospective cohort of sexually active gay, bisexual, and other men who have sex with men (MSM), aged ≥ 16 years in Vancouver, Canada. Follow-up occurred every 6 months, up to seven visits; at each visit participants reported their last sexual encounter with their five most recent partners. Stratified by self-reported HIV status, individual-level, interpersonal, and situational covariates of event-level CAS with partners met online were modeled using generalized estimating equations (GEE). CAS was reported during 32.4% (n = 1,015/3,133) of HIV-negative/unknown men's events, and 62.1% (n = 576/928) of HIV-positive men's events. Social (i.e., collective identity, altruism, network size social embeddedness) and situational (i.e., number of encounters, location, comparative age, seroconcordance, substance use) factors were identified as important correlates of CAS. Implications include the need for HIV prevention addressing social contexts associated with CAS.

Does age matter? Sexual event-level analysis of age-disparate sexual partners among gay, bisexual and other men who have sex with men (GBM) in Vancouver, Canada

BACKGROUND

To determine factors associated with age-disparate sexual partners among Vancouver gay, bisexual and other men who have sex with men (GBM).

METHODS

Sexually active GBM aged ≥16 years were recruited from February 2012 to February 2014. Participants self-completed a questionnaire on demographics, attitudes and sexual behaviour and substance use at last sexual event with five most recent partners. Two generalised linear mixed models identified factors associated with: (1) 'same-age' (referent), 'younger' or 'much-younger' and (2) 'same-age' (referent), 'older' or 'much-older' partners. Statistical interactions between age and HIV status were tested.

RESULTS

Participants (n=719) were predominantly gay (85.1%), White (75.0%), HIV-negative/unknown status (72.9%) with median age of 33 years (Q1,Q3: 26,47). A minority of sexual events were reported with much-older/much-younger partners (13.7%). In the multivariable models, GBM reporting older partners were more likely to be Asian or Latino, have greater Escape Motivation scores, report their partner used erectile dysfunction drugs (EDDs) and have received something for sex; compared with condom-protected insertive anal sex, participants with older partners were more likely to report condomless insertive anal sex with a serodiscordant or unknown status partner or no insertive anal sex. GBM reporting older partners were less likely to be bisexual-identified, have given something for sex and report event-level alcohol and EDD use. GBM reporting younger partners were more likely to have annual incomes >$30 000 and have met their partner online. As per significant statistical interactions, age-disparate relations were more common for younger HIV-positive and older HIV-negative GBM.

CONCLUSIONS

Differences among age-disparate partners highlight important targets for health promotion and future research.