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.

Virological suppression among gay, bisexual, and other men who have sex with men living with HIV in Vancouver, Canada: A longitudinal cohort study from 2012-2017

INTRODUCTION

In 2010, British Columbia (BC) implemented HIV Treatment as Prevention (TasP) as policy. We examined trends in virologic suppression and determinants of significant viremia among a prospective biobehavioural cohort of men who have sex with men (gbMSM) in Vancouver from 2012-2017.

METHODS

Respondent-driven sampling was used to recruit sexually active gbMSM (≥16 years) who completed biannual study visits with a computer-assisted self-interview and clinical CD4 and viral load (VL) testing. We linked participant data with the BC HIV Drug Treatment Program to obtain antiretroviral dispensing and VL data. We conducted a trend analysis of VL suppression using univariable generalized estimating equation (GEE) multi-level modelling and multivariable GEE to identify factors associated with episodes of VL ≥200 copies/mL.

RESULTS

Of 774 participants, 223 were living with HIV at baseline and 16 were diagnosed during follow-up (n = 239). We observed a significant trend towards reduced levels of unsuppressed VL (>200 copies/mL) from 22% (07/2012-12/2012) to 12% (07/2016-12/2016) (OR:0.87; 95%CI:0.83-0.91 for each 6-month period). Among those with at least one follow-up visit, (n = 178, median follow-up = 3.2 years, median age = 46.9 years), younger age (aOR:0.97; 95%CI:0.94-0.99, per year), ecstasy use (aOR:1.69; 95%CI:1.13-2.53), crystal methamphetamine use (aOR:1.71; 95%CI:1.18-2.48), seeking sex via websites (aOR:1.46; 95%CI:1.01-2.12), and lower HIV treatment optimism (aOR:0.94; 95%CI:0.90-0.97) were associated with episodes of elevated viremia.

CONCLUSIONS

During a period when TasP policy was actively promoted, we observed a significant trend towards reduced levels of unsuppressed VL. Continued efforts should promote HIV treatment optimism and engagement, especially among younger gbMSM and those who use ecstasy and crystal methamphetamine.

Factors associated with transactional sex among a cohort of gay, bisexual, and other men who have sex with men in Vancouver, Canada

Background Gay, bisexual, and other men who have sex with men (GBM) who engage in transactional sex (sex in exchange for drugs, money, or goods) experience increased risk of sexually transmitted infections (STI), including HIV. This study explored additional psychosocial and health-related factors associated with transactional sex among GBM. Methods Respondent-driven sampling was used to recruit GBM in Vancouver, Canada, from 2012 to 2015, with follow up every 6months until July2019. We examined factors associated with transactional sex using multivariable three-level mixed-effects modelling. Results Among 698 GBM, 22.1% reported ever receiving drugs, money, or goods for sex. Transactional sex was more likely to be reported by GBM who were younger (<30years) and who had lower incomes, less education, and insecure housing. GBM reporting transactional sex were more likely to report substance use (i.e. crystal methamphetamine, poppers, GHB, and non-steroid injection drugs) and higher risk sexual behaviours (i.e. more sex partners, sex party attendance, and condomless anal sex with serodifferent or unknown HIV status partners); however, they were no more likely to be living with HIV or to report a recent bacterial STI diagnosis. GBM who reported higher loneliness, anxiety, and cognitive escape were also more likely to report transactional sex. Conclusions More than one-fifth of GBM in Vancouver reported transactional sex and those who did were more likely to also experience psychosocial stressors, increased substance use, and higher risk sexual behaviours. Programs which consider the interconnections of personal, social, and structural challenges faced by GBM engaging in transactional sex are necessary to support improved mental, physical, and sexual health for these men.

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.

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.

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.

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.

Factors Associated with Cessation or Reduction of Methamphetamine Use among Gay, Bisexual, and Other Men Who Have Sex with Men (gbMSM) in Vancouver Canada

Background: Methamphetamine (MA) use among gay, bisexual, and other men who have sex with men (gbMSM) is a pervasive issue, associated with detrimental health outcomes. We identified factors associated with discontinuation or reduction in MA among a subset of gbMSM reporting frequent (at least weekly) use, with a specific focus on symptoms of anxiety and depression. Methods: We recruited sexually-active gbMSM aged ≥16 years in Vancouver, Canada into a prospective-cohort study using respondent-driven sampling. Participants completed study visits once every six months. We used generalized linear mixed models to identify factors associated with reductions in MA use following a visit where participants previously reported using MA at least weekly. Results: Of 584 cohort participants with at least one follow-up visit, 67 (11.5%) reported frequent MA use at baseline or in follow-up visits. Of these, 46 (68.7%) had at least one subsequent study visit where they transitioned to less frequent (monthly or less) or no MA use. In multivariable models, reduced MA use was less likely for those who spent >50% of social time with other gbMSM (aRR = 0.49, 95%CI:0.28-0.85), gave or received drugs in exchange for sex (aRR = 0.34, 95%CI:0.13-0.87), injected drugs (aRR = 0.35, 95%CI:0.18-0.68), or used gamma-hydroxybutyrate (GHB) (aRR = 0.41, 95%CI:0.21-0.78). Symptoms of anxiety or depression were not associated with reductions in MA use. Conclusions: Social connection and drug-related factors surrounding MA use were associated with reductions, but anxiety and depressive symptomatology were not. Incorporating socialization and polysubstance-related components with MA reduction may help in developing efficacious interventions toward reducing MA use for gbMSM.

Escape expectancies and sexualized substance use among gay, bisexual, and other men who have sex with men

McKirnan's Cognitive Escape Theory (1996) is often characterized by the hypothesis that drugs are used during sex by gay, bisexual, and other men who have sex with men (gbMSM) to relieve internal cognitive conflict over safe-sex norms and sexual desire. We examined how McKirnan's Cognitive Escape Scale (CES) is related to other widely used constructs relevant to sexualized substance use with hopes of better situating the theory within the evolving landscape of HIV-prevention. Associations between CES and trait anxiety, depression, treatment optimism, sexual altruism, sexual sensation seeking, and self-perceived risk for HIV transmission/acquisition were tested. Mediation analyses tested whether associated psychological measures mediated the effect of CES on the proportion of events in which participants reported co-occurrent substance use and condomless anal sex. Results indicated that CES is associated with higher sexual sensation seeking, treatment optimism, trait anxiety, and perceived likelihood of HIV transmission/acquisition. Mediation analyses suggest that CES is related to but operates independently of treatment optimism, sensation seeking, and trait anxiety. Nevertheless, the intersection of HIV-related worries and substance use expectancies are clearly more nuanced than is widely reported is discussions on cognitive escape.

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 longitudinal analysis of cannabis use and mental health symptoms among gay, bisexual, and other men who have sex with men in Vancouver, Canada

BACKGROUND

Cannabis use, anxiety, and depression are common among gay, bisexual, and other men who have sex with men (gbMSM) and some report using cannabis to manage mental health symptoms.

METHODS

Sexually-active gbMSM aged ≥16 years were recruited into a longitudinal cohort through respondent-driven sampling and completed study visits every six months. Data on demographics, drug use, and anxiety and depression symptoms were collected via a self-administered computer-based survey. A study nurse determined previous mental health diagnoses and treatment. Using multivariable generalized linear mixed models, we examined factors associated with regular cannabis use (≥weekly in the previous 3 months) and, among individuals who reported anxiety or depression/bipolar diagnoses, factors associated with moderate/severe anxiety or depression symptoms.

RESULTS

Of 774 participants (551 HIV-negative, 223 HIV-seropositive), 250 (32.3%) reported regular cannabis use, 200 (26.4%) reported ever being diagnosed with anxiety, and 299 (39.3%) reported ever being diagnosed with depression or bipolar disorder at baseline. Regular cannabis use was positively associated with HIV-seropositivity (aOR = 2.23, 95%CI:1.40-3.54) and previous mental health diagnosis (aOR = 1.52, 95%CI: 1.00-2.31, p = 0.05). Among those previously diagnosed with anxiety or depression/bipolar disorder, regular cannabis use was not associated with moderate/severe anxiety (aOR = 1.16, 95%CI:0.69-1.94) or depression symptoms (aOR = 0.96, 95%CI:0.59-1.58), respectively.

LIMITATIONS

Because of observational study design, we are unable to determine absolute effect.

CONCLUSIONS

Regular cannabis use was more likely among HIV-positive gbMSM and those previously diagnosed with a mental health disorder. No association was found between regular cannabis use and severity of anxious or depressive symptoms among those diagnosed with these conditions.

HIV Testing Among a Representative Community Sample of Gay, Bisexual, and Other Men Who Have Sex with Men in Vancouver, Canada

Earlier HIV diagnosis allows for improved treatment outcomes and secondary prevention. It is recommended that all individuals know their HIV status and that those at higher risk test more frequently. Using a representative community sample of gay, bisexual, and other men who have sex with men (GBMSM), we aimed to: (1) determine the proportion of GBMSM who have tested in the past 2 years, (2) determine reasons for testing and never having tested, and (3) explore correlates of testing. Of 535 eligible participants, 80.0% reported having had an HIV test in the past 2 years, most commonly as part of a regular testing schedule. The most common reason for not testing was low perceived HIV risk. Bisexual and older GBMSM, as well as those who lived outside of Vancouver, were less likely to have tested in the past 2 years. Rapid point-of-care testing may help improve testing rates and was shown to effectively engage some hard-to-reach GBMSM (e.g., those who had not tested for other STIs) in this sample.

"Condoms are … like public transit. It's something you want everyone else to take": Perceptions and use of condoms among HIV negative gay men in Vancouver, Canada in the era of biomedical and seroadaptive prevention

BACKGROUND

The emergence of biomedical and seroadaptive HIV prevention strategies has coincided with a decline in condom use among gay men.

METHODS

We undertook a social ecological analysis of condom use and perceptions using nineteen semi-structured interviews with HIV negative gay men in Vancouver, Canada who used HAART-based prevention strategies.

RESULTS

Contributors to inconsistent condom use were found at various levels of the social ecological model. Ongoing concern regarding HIV transmission and belief in the proven efficacy of condoms motivated contextual use. When condoms were not used, participants utilized seroadaptive and biomedical prevention strategies to mitigate risk.

CONCLUSIONS

These findings indicate that notions of "safety" and "risk" based on consistent condom use are eroding as other modes of prevention gain visibility. Community-based and public health interventions will need to shift prevention messaging from advocacy for universal condom use toward combination prevention in order to meet gay men's current prevention needs. Interventions should advance gay men's communication and self-advocacy skills in order to optimize these strategies.

Substance Use as a Mechanism for Social Inclusion among Gay, Bisexual, and Other Men Who Have Sex with Men in Vancouver, Canada

Background: Previous research demonstrates that substance use preferences and social-sexual environments are highly interrelated for gay, bisexual, and other men who have sex with men (gbMSM). Objective: We conducted a qualitative study to explore the socio-cultural context of substance use among local gbMSM communities in Metro Vancouver, Canada. Methods: Twenty gbMSM were purposively sampled from the larger Momentum Health Study cohort, a sexual health study of gbMSM in Greater Vancouver. Participants were demographically diverse in terms of HIV serostatus, age, income, ethnicity, and area of residence within the city and neighboring suburbs. Community maps generated by participants during formative research served as prompts for semi-structured interviews which were audio recorded and transcribed verbatim. Thematic analysis identified three themes of common experience. Results: First, participants indicated that substance use is intrinsically social in Vancouver gbMSM communities and that it functions as both a means of social inclusion and exclusion. Second, a distinction was made between types of substances and the location and context of their use, with specific substances having particular uses and meanings. Third, analysis suggested that gbMSM change their substance use over the life course and that this is affected by shifting priorities as people age. Discussion: For Vancouver gbMSM communities, substance use serves several social-cultural functions and can simultaneously serve as both a potential facilitator and barrier for community connection. Future research and health programing should consider venue and context specific messaging and recognize the heterogeneity of substance use within the larger gbMSM population.

A Narrative Review of Internet Use, Interpersonal Connectedness, and Sexual Behaviour Among Gay, Bisexual and Other Men Who Have Sex With Men

Researchers have often considered the impact that online dating has had on gay communities; with some arguing that changes in social behavior may impact the spread of HIV. However, these conclusions are based on the premise that the Internet has fundamentally changed the way gay and bisexual men connect with their communities. Addressing this issue, we searched the PubMed and Web of Science databases for studies examining Internet use and interpersonal connectedness among gay and bisexual men to determine whether those who used the Internet to find sexual partners exhibited different patterns of community connectedness. Though sporadic, findings suggest that Internet use may be associated with lower gay identity, community attachment, and social embeddedness. However, recent reports have suggested that online sex seeking might be associated with greater, not less, interpersonal connectedness. We conclude that additional longitudinal analyses and consistent measurement of gay men's social behavior are needed to draw more definite conclusions.

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.

Sexual orientation measurement, bisexuality, and mental health in a sample of men who have sex with men in Vancouver, Canada

This cross-sectional study used a validated index (i.e., Hospital Anxiety and Depression Scale) to measure anxiety and depression (caseness score: ≥8) among men who have sex with men recruited via respondent-driven sampling in Vancouver, Canada (n=774), and investigated whether differences in mental health outcomes varied by sexual orientation measure (i.e., identity, attraction, behavior). Of the sample, 15.5% identified as bisexual, 33.4% reported any bisexual attraction, and 22.7% reported any bisexual sexual activity. More bisexual than gay men met the case definition for anxiety and depression, across all sexual orientation measures. In adjusted multivariable models, bisexual men had higher odds of anxiety by attraction and identity and higher odds of depression by identity. Findings highlight the value of measuring multiple sexual orientation dimensions in surveys and routine surveillance, and the need to ensure sexual minority groups and sexual orientation dimensions are not considered commensurate for mental health prevention and treatment.

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.

Estimating the Size of the MSM Population in Metro Vancouver, Canada, Using Multiple Methods and Diverse Data Sources

Men who have sex with men (MSM) are disproportionately affected by HIV globally, regionally in Canada, and locally in Vancouver. Lack of reliable population size estimates of MSM impedes effective implementation of health care services and limits our understanding of the HIV epidemic. We estimated the population size of MSM residing in Metro Vancouver drawing on four data sources: the Canadian Community Health Survey (CCHS), a cross-sectional bio-behavioural MSM survey, HIV testing services data from sexually transmitted infection (STI) clinics serving MSM, and online social networking site Facebook. Estimates were calculated using (1) direct estimates from the CCHS, (2) "Wisdom of the Crowds" (WOTC), and (3) the multiplier method using data from a bio-behavioural MSM survey, clinic-based HIV testing, and online social media network site Facebook. Data sources requiring greater public disclosure of sexual orientation resulted in our mid-range population estimates (Facebook 23,760, CCHS 30,605). The WOTC method produced the lowest estimate, 10,000. The multiplier method using STI clinic HIV testing data produced the largest estimate, 41,777. The median of all estimates was 27,183, representing 2.9% of the Metro Vancouver census male adult population, with an interquartile range of 1.1-4.5%. Using multiple data sources, our estimates of the MSM population in Metro Vancouver are similar to population prevalence estimates based on population data from other industrialized nations. These findings will support understanding of the HIV burden among MSM and corresponding public health and health services planning for this key population.

A Latent Class Analysis of Seroadaptation Among Gay and Bisexual Men

Initial research into seroadaptive strategies suggests that, individually, they are potentially effective behavioral methods to reduce risk of HIV transmission. Combining strategies, therefore, has the potential to increase risk reduction. The aim of this study was to determine how gay and bisexual men (GBM) combine strategies. To this end, a total of 774 sexually active GBM, aged ≥16 years, in Metro Vancouver, Canada, were recruited. Grouped by self-reported HIV status, latent class analysis of self-reported condom use, strategic positioning, anal sex avoidance, serosorting, viral-load sorting, and withdrawal were conducted. Multinomial logistical regression identified explanatory variables of class membership (i.e., sensation seeking, treatment optimism, sexual altruism, relationship status, number of partners, anal sex preference). Four latent classes were identified: Condom Users, Multiple Prevention Users, Viral-Load Sorters, and Serosorters. The majority of HIV-negative/unknown men (72 %) and a large proportion of HIV-positive men (42 %) belonged to the Condom Users class. Class membership was associated with age, relationship status, treatment optimism, sexual altruism, sensation seeking, number of recent male anal sex partners, and recent condomless anal sex with a serodiscordant or unknown-status partner. Understanding these distinct patterns allows for tailored interventions addressing GBM's sexual health needs.

Changes in smoking status among a longitudinal cohort of gay, bisexual, and other men who have sex with men in Vancouver, Canada

BACKGROUND

Cigarette smoking is common among gay, bisexual, and other men who have sex with men (GBMSM) and most of the mortality gap between HIV-positive and HIV-negative individuals is attributable to smoking.

METHODS

We recruited sexually active HIV-positive and HIV-negative GBMSM age ≥16 years using respondent-driven sampling. Study visits occurred every six months for up to four years and included a computer-assisted self-interview and clinical assessment. We conducted bivariate analyses to compare factors associated with "never", "former", "daily", or "non-daily" smoking at baseline and longitudinal mixed effects models to examine factors associated with cessation and (re)initiation.

RESULTS

774 participants completed a baseline visit and 525 enrolled in the cohort and completed at least one follow-up visit. At baseline, the median age was 34 years and 31.5% were daily smokers. In follow-up (median=2.5years), 116 daily or non-daily smokers (41%) quit at least once and of these, 101 (87%) remained former smokers at their last visit. Smoking cessation was positively associated with incomes ≥$60,000 and self-reported excellent health. Alcohol use, ecstasy use, and having a partner who smokes were associated with decreased odds of cessation. Substance use (cannabis, GHB, and crystal methamphetamine) and having a partner who smokes were positively associated with increasing to/resuming daily smoking. HIV-positive GBMSM were more likely to smoke but not more likely to quit.

CONCLUSIONS

Targeted, culturally relevant smoking cessation resources are needed, especially for HIV-positive GBMSM. Engaging couples in cessation interventions may be useful.

Gay Men's Understanding and Education of New HIV Prevention Technologies in Vancouver, Canada

Effective rollout of HIV treatment-based prevention such as pre-exposure prophylaxis and treatment as prevention has been hampered by poor education, limited acceptability, and stigma among gay men. We undertook a thematic analysis regarding the education sources and acceptability of these New Prevention Technologies (NPTs) using 15 semistructured interviews with gay men in Vancouver, Canada, who were early adopters of NPTs. NPT education was derived from a variety of sources, including the Internet, health care providers, community organizations, sexual partners, and peers; participants also emphasized their own capacities as learners and educators. Acceptable forms of NPT education featured high-quality factual information, personal testimony, and easy access. Stigma was highlighted as a major barrier. For public health, policy makers, and gay communities to optimize the personal and population benefits of NPTs, there is a need for increased community support and dialogue, antistigma efforts, early NPT adopter testimony, and personalized implementation strategies.

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.

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.

Does size really matter? A sensitivity analysis of number of seeds in a respondent-driven sampling study of gay, bisexual and other men who have sex with men in Vancouver, Canada

Background

Respondent-driven sampling (RDS) is an increasingly used peer chain-recruitment method to sample “hard-to-reach” populations for whom there are no reliable sampling frames. Implementation success of RDS varies; one potential negative factor being the number of seeds used.

Methods

We conducted a sensitivity analysis on estimates produced using data from an RDS study of gay, bisexual and other men who have sex with men (GBMSM) aged ≥16 years living in Vancouver, Canada. Participants completed a questionnaire on demographics, sexual behavior and substance use. For analysis, we used increasing seed exclusion criteria, starting with all participants and subsequently removing unproductive seeds, chains of ≤1 recruitment waves, and chains of ≤2 recruitment waves. We calculated estimates for three different outcomes (HIV serostatus, condomless anal intercourse with HIV discordant/unknown status partner, and injecting drugs) using three different RDS weighting procedures: RDS-I, RDS-II, and RDS-SS. We also assessed seed dependence with bottleneck analyses and convergence plots. Statistical differences between RDS estimators were assessed through simulation analysis.

Results

Overall, 719 participants were recruited, which included 119 seeds and a maximum of 16 recruitment waves (mean chain length = 1.7). The sample of >0 recruitment waves removed unproductive seeds (n = 50/119, 42.0%), resulting in 69 chains (mean length = 3.0). The sample of >1 recruitment waves removed 125 seeds or recruits (17.4% of overall sample), resulting in 37 chains (mean length = 4.8). The final sample of >2 recruitment waves removed a further 182 seeds or recruits (25.3% of overall sample), resulting in 25 chains (mean length = 6.1). Convergence plots and bottleneck analyses of condomless anal intercourse with HIV discordant/unknown status partner and injecting drugs outcomes were satisfactory. For these two outcomes, regardless of seed exclusion criteria used, the crude proportions fell within 95% confidence intervals of all RDS-weighted estimates. Significant differences between the three RDS estimators were not observed.

Conclusions

Within a sample of GBMSM in Vancouver, Canada, this RDS study suggests that when equilibrium and homophily are met, although potentially costly and time consuming, analysis is not negatively affected by large numbers of unproductive or lowly productive seeds.

Electronic supplementary material

The online version of this article (doi:10.1186/s12874-016-0258-4) contains supplementary material, which is available to authorized users.

Event-Level Analysis of Anal Sex Roles and Sex Drug Use Among Gay and Bisexual Men in Vancouver, British Columbia, Canada

This study analyzed event-level partnership data from a computer-assisted survey of 719 gay and bisexual men (GBM) enrolled in the Momentum Health Study to delineate potential linkages between anal sex roles and the so-called "sex drugs," i.e., erectile dysfunction drugs (EDD), poppers, and crystal methamphetamine. Univariable and multivariable analyses using generalized linear mixed models with logit link function with sexual encounters (n = 2514) as the unit of analysis tested four hypotheses: (1) EDD are significantly associated with insertive anal sex roles, (2) poppers are significantly associated with receptive anal sex, (3) both poppers and EDD are significantly associated with anal sexual versatility, and (4) crystal methamphetamine is significantly associated with all anal sex roles. Data for survey respondents and their sexual partners allowed testing these hypotheses for both anal sex partners in the same encounter. Multivariable results supported the first three hypotheses. Crystal methamphetamine was significantly associated with all anal sex roles in the univariable models, but not significant in any multivariable ones. Other multivariable significant variables included attending group sex events, venue where first met, and self-described sexual orientation. Results indicate that GBM sex-drug use behavior features rational decision-making strategies linked to anal sex roles. They also suggest that more research on anal sex roles, particularly versatility, is needed, and that sexual behavior research can benefit from partnership analysis.

Awareness and use of nonoccupational post-exposure prophylaxis among men who have sex with men in Vancouver, Canada

OBJECTIVES

Nonoccupational post-exposure prophylaxis (nPEP) is a strategy to reduce the risk of HIV infection in those with high-risk exposure. This study characterized nPEP awareness among gay, bisexual and other men who have sex with men (MSM) in Metro Vancouver, British Columbia, Canada after a pilot nPEP programme established in 2012.

METHODS

Momentum Health Study participants were MSM aged ≥16 years recruited via respondent-driven sampling (RDS) who completed a computer-assisted self-interview. Stratifying patients by HIV status, we used multivariable logistic regression with backward selection to identify factors associated with nPEP awareness. All analyses were RDS-adjusted.

RESULTS

A total of 51.9% (112 of 173) of HIV-positive and 48.5% (272 of 500) of HIV-negative participants had heard of nPEP. Only 3% (five of 106) of HIV-negative participants who reported recent high-risk sex used nPEP. Generally, nPEP awareness was higher for participants who engaged in sexual activities with increased HIV transmission potential. Factors associated with greater awareness among HIV-negative participants included recent alcohol use, higher communal sexual altruism, previous sexually transmitted infection diagnosis, and greater perceived condom use self-efficacy. Other factors associated with greater awareness among HIV-negative participants included white race/ethnicity, gay sexual identity, more formal education, lower personal sexual altruism, and Vancouver residence. Greater nPEP awareness among HIV-positive participants was associated with greater perceived agency to ask sexual partners' HIV status and more frequently reporting doing so, a higher number of lifetime receptive sex partners, and greater access to condoms.

CONCLUSIONS

Following implementation of an nPEP pilot programme, nPEP awareness among HIV-negative MSM was 51% and use was 3%. These data support the need to expand access to and actively promote nPEP services.

Factors Associated with Productive Recruiting in a Respondent-Driven Sample of Men who Have Sex with Men in Vancouver, Canada

Respondent-driven sampling (RDS) has become a preferred sampling strategy for HIV research and surveillance in many global settings. Methodological investigation into the validity of RDS-generated samples has helped improve theoretical components of design. However, the operational challenges of implementing RDS remain underreported. We sought to identify factors independently associated with productive recruiting in an urban RDS-generated sample of gay, bisexual, and other men who have sex with men (MSM). Data were collected from the Momentum Health Study, a cohort of MSM recruited by RDS in Vancouver, Canada. Eligible men were given up to six RDS coupons to recruit their peers. The primary outcome was a count variable of each participant's number of eligible recruits. Multivariable Poisson regression identified independent predictors of productive recruitment. In total, 719 individuals comprised this analysis, of which 119 were seeds. The distribution of eligible recruits was right skewed, with 391 (54.4 %) having never recruited another participant and only eight participants (1.1 %) having recruited five. Significant, independent predictors of recruiting one additional participant included network size per ten unit increase (adjusted risk ratio [aRR] 1.03), being of Aboriginal race/ethnicity compared with White (aRR 1.51), being HIV-positive (aRR 1.31), being sexually active with only males (aRR 2.48), being single compared with common law/married (aRR 1.37), having recently read gay newspapers (aRR 1.58), having recently sought sex partners online (aRR 1.33) and being out to a male parent (aRR 1.30). This analysis demonstrates the importance of social network size in RDS adjustment, but also identifies other socio-demographic and behavioral variables that increased RDS coupon return, which may help researchers better operationalize the implementation of RDS.

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

Background

Technology has changed the way men who have sex with men (MSM) seek sex and socialize, which may impact the implementation of respondent-driven sampling (RDS) among this population. Initial participants (also known as seeds) are a critical consideration in RDS because they begin the recruitment chains. However, little information is available on how the online-recruited seeds may effect RDS implementation.

Objective

The objectives of this study were to compare (1) online-recruited versus offline-recruited seeds and (2) subsequent recruitment chains of online-recruited versus offline-recruited seeds.

Methods

Between 2012 and 2014, we recruited MSM using RDS in Vancouver, Canada. RDS weights were used with logistic regression to address each objective.

Results

A total of 119 seeds were used, 85 of whom were online-recruited seeds, to recruit an additional 600 MSM. Compared with offline-recruited seeds, online-recruited seeds were less likely to be HIV-positive (OR 0.34, 95% CI 0.13-0.88), to have attended a gay community group (AOR 0.33, 95% CI 0.12-0.90), and to feel gay community involvement was “very important” (AOR 0.16, 95% CI 0.03-0.93). Online-recruited seeds were more likely to ask a sexual partner’s HIV status always versus <50% of the time (AOR 5.21, 95% CI 1.17-23.23), to have watched the Pride parade (AOR 6.30, 95% CI 1.69-23.45), and to have sought sex online (AOR 4.29, 95% CI 1.53-12-12.05). Further, compared with recruitment chains started by offline-recruited seeds, recruits from chains started by online-recruited seeds (283/600, 47.2%) were less likely to be HIV-positive (AOR 0.25, 95% CI 0.16-0.40), to report “versatile” versus “bottom” sexual position preference (AOR 0.56, 95% CI 0.35-0.88), and to be in a relationship lasting >1 year (AOR 1.65, 95% CI 1.06-2.56). Recruits of online seeds were more likely to be out as gay for longer (eg, 11-21 vs 1-4 years, AOR 2.22, 95% CI 1.27-3.88) and have fewer Facebook friends (eg, 201-500 vs >500, AOR 1.69, 95% CI 1.02-2.80).

Conclusions

Online-recruited seeds were more prevalent, recruited fewer participants, but were different from those recruited offline. This may therefore help create a more diverse overall sample. Our work has shown the value of geosocial networking apps for aiding RDS recruitment efforts, especially when faced with slow participation uptake by other means. Understanding the degree to which networks interact will be an important next step in confirming the efficacy of online RDS recruitment strategies.

Substance use, sexual behaviour and prevention strategies of Vancouver gay and bisexual men who recently attended group sex events

Group sex events are an epidemiologically important part of some gay and bisexual men's sexual culture in Canada. Associated with condomless anal intercourse and polysubstance use, such events have been cited as disproportionally contributing to HIV infection rates. We analysed questionnaire data from the Momentum Health Study in Vancouver, Canada, to understand substance use, sexual behaviour, psychosocial variables (Sexual Sensation Seeking, Sexual Escape Motivation, Treatment Optimism) and HIV prevention strategies (sero-sorting, strategic positioning, avoiding anal sex, disclosure, treatment as prevention) of men attending such events, which were defined as group (n ≥ 4 partners) sex parties, blackout events and darkrooms. Analysis by multivariable logistic regression compared men attending group sex events within the past six months (n = 180) with non-attendees (n = 539). Results showed that attendees reported: (1) significantly higher use of sex drugs and alcohol consumption, (2) higher scores on the Sexual Sensation Scale, more anal sex partners, greater odds of any condomless anal sex with sero-discordant partners and greater odds of reporting fisting and sex toy use and (3) different prevention practices that varied by HIV-serostatus. Findings are interpreted in light of the importance of pleasure, sociality and HIV/STI prevention strategies associated with group sex events. Findings contribute to the development of appropriate education and intervention for attendees.

A comparison of motivations for use among users of crack cocaine and cocaine powder in a sample of simultaneous cocaine and alcohol users

This study examined the motivations for using cocaine and alcohol comparing those who primarily smoked crack and those who primarily used cocaine powder when using simultaneously with alcohol. Motivations examined included: 1) to cope with a negative affect, 2) enhancement, 3) to be social and 4) to conform. The research design was a cross-sectional study in which clients in treatment for cocaine and alcohol problems completed a self-administered questionnaire about their substance use. Among those who primarily smoked crack or snorted cocaine when also using alcohol (n=153), there were 93 participants who reported primarily snorting cocaine and 60 participants who primarily reported smoking crack. Bivariate analyses found that those who primarily smoked crack reported lower social motivations to use alcohol and cocaine. When adjusting for other covariates in a multivariate analysis, social motivation was still significantly different between groups. Additionally, those who primarily smoked crack were more likely to be older, report higher cocaine dependence severity, be unemployed and were less likely to have completed some post-secondary education, than those who primarily snorted cocaine. No differences were found in enhancement, coping or conformity motivations between the two groups. These results suggest that simultaneous cocaine and alcohol use may have social importance to those who primarily snort cocaine, but that this importance is less evident to those who smoke crack. Consequently, future studies examining motivations for simultaneous cocaine and alcohol use should distinguish between different routes of cocaine administration.

Community mapping and respondent-driven sampling of gay and bisexual men's communities in Vancouver, Canada

Literature suggests formative research is vital for those using respondent-driven sampling (RDS) to study hidden populations of interest. However, few authors have described in detail how different qualitative methodologies can address the objectives of formative research for understanding the social network properties of the study population, selecting seeds and adapting survey logistics to best fit the population. In this paper we describe the use of community mapping exercises as a tool within focus groups to collect data on social and sexual network characteristics of gay and bisexual men in the metropolitan area of Vancouver, Canada. Three key themes emerged from analysing community maps along with other formative research data: (1) connections between physical spaces and social networks of gay and bisexual men, (2) diversity in communities and (3) substance use linked to formation of sub-communities. We discuss how these themes informed the planning and operations of a longitudinal epidemiological cohort study recruited by RDS. We argue that using community mapping within formative research is a valuable qualitative tool for characterising network structures of a diverse and differentiated population of gay and bisexual men in a highly developed urban setting.

Intergenerational sex as a risk factor for HIV among young men who have sex with men: a scoping review

An emerging body of evidence suggests that intergenerational sexual partnerships may increase risk of HIV acquisition among young men who have sex with men (YMSM). However, no studies have comprehensively evaluated literature in this area. We applied a scoping review methodology to explore the relationships between age mixing, HIV risk behavior, and HIV seroconversion among YMSM. This study identified several individual, micro-, and meso-system factors influencing HIV risk among YMSM in the context of intergenerational relationships: childhood maltreatment, coming of age and sexual identity, and substance use (individual-level factors); family and social support, partner characteristics, intimate partner violence, connectedness to gay community (micro-system factors); and race/ethnicity, economic disparity, and use of the Internet (meso-system factors). These thematic groups can be used to frame future research on the role of age-discrepant relationships on HIV risk among YMSM, and to enhance public health HIV education and prevention strategies targeting this vulnerable population.

Family Kinship Patterns and Female Sex Work in the Informal Urban Settlement of Kibera, Nairobi, Kenya

A basic ecological and epidemiological question is why some women enter into commercial sex work while other women in the same socio-economic environment never do. To address this question respondent driven sampling principles were adopted to recruit and collect data for 161 female sex workers and 159 same aged women who never engaged in commercial sex in Kibera, a large informal settlement in Nairobi, Kenya. Univariate analysis indicated that basic kinship measures, including number of family members seen during adolescence and at present, not having a male guardian while growing up, and earlier times of ending relationships with both male and female guardians were associated with commercial sex work in Kibera. Multivariate analysis via logistic regression modeling showed that not having a male guardian during childhood, low education attainment and a small number of family members seen at adolescence were all significant predictors of entering sex work. By far the most important predictor of entering sex work was not having any male guardian, e.g., father, uncle, older brother, etc. during childhood. Results are interpreted in light of the historic pattern of sub-Saharan African child fostering and their relevance for young women in Kibera today.

Worry as a window into the lives of people who use injection drugs: a factor analysis approach

BACKGROUND

The concept of risk dominates the HIV/AIDS literature pertaining to People Who Use Injection Drugs (PWUID). In contrast the associated concept of worry is infrequently applied, even though it can produce important perspectives of PWUID's lives. This study asked a sample (n = 105) of PWUID enrolled in a Victoria, British Columbia needle exchange program to evaluate their degree of worry about fourteen factors they may encounter in their daily lives.

METHODS

Exploratory factor analysis was used to analyze their responses.

RESULTS

Factor analysis delineated three factors: 1) overall personal security, 2) injection drug use-specific risks including overdosing and vein collapse and, 3) contracting infectious diseases associated with injection drug use (e.g. HIV/AIDS and hepatitis C).

CONCLUSION

PWUID in this study not only worry about HIV/AIDS but also about stressful factors in their daily life which have been linked to both increased HIV/AIDS risk behaviour and decreased anti-retroviral treatment adherence. The importance PWUID give to this broad range of worry/concerns emphasizes the need to place HIV/AIDS intervention, education, and treatment programs within a broader harm-reduction framework that incorporates their perspectives on both worry and risk.

Inkjet printing for high-throughput cell patterning

The adaptation of inkjet printing technology to the complex fields of tissue engineering and biomaterial development presents the potential to increase progress in these emerging technologies through the implementation of this high-throughput capability via automated processes to enable precise control and repeatability. In this paper, a method of applying high-throughput inkjet printing to control cellular attachment and proliferation by precise, automated deposition of collagen is presented. The results indicate that commercial inkjet printing technology can be used to create viable cellular patterns with a resolution of 350 microm through the deposition of biologically active proteins. This method demonstrates a combination of off-the-shelf inkjet printing and biomaterials and has potential to be adapted to tissue engineering and colony patterning applications. Adapting this method into the three-dimensional construction of cellular structures for eventual high-throughput tissue engineering using a bottom-up approach is possible.