Reaching men who have sex with men: a comparison of respondent-driven sampling and time-location sampling in Guatemala City

Mobile Phone-Based Confidential Social Network Referrals for HIV Testing (CONSORT): Protocol for a Randomized Controlled Trial

BACKGROUND

Critical to efforts to end the HIV epidemic is the identification of persons living with HIV who have yet to be diagnosed and engaged in care. Expanded HIV testing outreach efforts need to be both efficient and ambitious, targeting the social networks of persons living with HIV and those at above-average risk of undiagnosed HIV infection. The ubiquity of mobile phones across many high HIV prevalence settings has created opportunities to leverage mobile health (mHealth) technologies to engage social networks for HIV testing outreach, prevention, and treatment.

OBJECTIVE

The purpose of this study is to evaluate the acceptability and efficacy of a novel mHealth intervention, "Confidential Social Network Referrals for HIV Testing (CONSORT)," to nudge at-risk individuals to test for HIV using SMS text messages.

METHODS

We will conduct the CONSORT study in Moshi, Tanzania, the commercial center and administrative capital of the Kilimanjaro Region in northern Tanzania. After qualitative formative work and pilot testing, we will enroll 400 clients presenting for HIV counseling and testing and 200 persons living with HIV and receiving care at HIV care and treatment centers as "inviters" into a randomized controlled trial. Eligible participants will be aged 18 years or older and live, work, or regularly receive care in Moshi. We will randomize inviters into 1 of 2 study arms. All inviters will be asked to complete a survey of their HIV testing and risk behaviors and to think of social network contacts who would benefit from HIV testing. They will then be asked to whom they would prefer to extend an HIV testing invitation in the form of a physical invitation card. Arm 1 participants will also be given the opportunity to extend CONSORT invitations in the form of automated confidential SMS text messages to any of their social network contacts or "invitees." Arm 2 participants will be offered physical invitation cards alone. The primary outcome will be counselor-documented uptake of HIV testing by invitees within 30 days of inviter enrollment. Secondary outcomes will include the acceptability of CONSORT among inviters, the number of new HIV diagnoses, and the HIV risk of invitees who present for testing.

RESULTS

Enrollment in the randomized controlled trial is expected to start in September 2024. The findings will be disseminated to stakeholders and published in peer-reviewed journals.

CONCLUSIONS

If CONSORT is acceptable and effective for increasing the uptake of HIV testing, given the minimal costs of SMS text reminders and the potential for exponential but targeted growth using chain referrals, it may shift current practices for HIV testing programs in the area.

TRIAL REGISTRATION

ClincalTrials.gov NCT05967208; https://clinicaltrials.gov/study/NCT05967208.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/55068.

Adaptive Time-Location Sampling for COMPASS: A SARS-CoV-2 Prevalence Study in Fifteen Diverse Communities in the United States

BACKGROUND

COVID-19 has placed a disproportionate burden on underserved racial and ethnic groups, community members working in essential industries, those living in areas of high population density, and those reliant on in-person services such as transportation. The goal of this study was to estimate the cross-sectional prevalence of SARS-CoV-2 (active SARS-CoV-2 or prior SARS-CoV-2 infection) in children and adults attending public venues in 15 sociodemographically diverse communities in the United States and to develop a statistical design that could be rigorously implemented amidst unpredictable stay-at-home COVID-19 guidelines.

METHODS

We used time-location sampling with complex sampling involving stratification, clustering of units, and unequal probabilities of selection to recruit individuals from selected communities. We safely conducted informed consent, specimen collection, and face-to-face interviews outside of public venues immediately following recruitment.

RESULTS

We developed an innovative sampling design that adapted to constraints such as closure of venues, changing infection hotspots, and uncertain policies. We updated both the sampling frame and the selection probabilities over time using information acquired from prior weeks. We created site-specific survey weights that adjusted sampling probabilities for nonresponse and calibrated to county-level margins on age and sex at birth.

CONCLUSIONS

Although the study itself was specific to COVID-19, the strategies presented in this article could serve as a case study that can be adapted for performing population-level inferences in similar settings and could help inform rapid and effective responses to future global public health challenges.

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.

ADAPTIVE TIME LOCATION SAMPLING FOR COMPASS, A SARS-COV-2 PREVALENCE STUDY IN FIFTEEN DIVERSE COMMUNITIES IN THE UNITED STATES

The COVPN 5002 (COMPASS) study aimed to estimate the prevalence of SARS-CoV-2 (active SARS-CoV-2 or prior SARS-CoV-2 infection) in children and adults attending public venues in 15 socio-demographically diverse communities in the United States. To protect against potential challenges in implementing traditional sampling strategies, time-location sampling (TLS) using complex sampling involving stratification, clustering of units, and unequal probabilities of selection was used to recruit individuals from neighborhoods in selected communities. The innovative design adapted to constraints such as closure of venues; changing infection hotspots; and uncertain policies. Recruitment of children and the elderly raised additional challenges in sample selection and implementation. To address these challenges, the TLS design adaptively updated both the sampling frame and the selection probabilities over time using information acquired from prior weeks. Although the study itself was specific to COVID-19, the strategies presented in this paper could serve as a case study that can be adapted for performing rigorous population-level inferences in similar settings and could help inform rapid and effective responses to future global public health challenges.

Implementation of a sample design for a survey of program participants using time-location sampling

To assess the feeding practices and behaviors of women and young children participating in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), USDA currently funds the longitudinal WIC Infant and Toddler Feeding Practices Study-2 (WIC ITFPS-2). In 2013, the study used time-location sampling (TLS) to enroll a cohort of infants who participated in WIC around birth. The children are subsequently followed across their first six years of life, regardless of their participation in WIC, with an additional follow-up at age nine years. A woman may enroll her child in WIC either during pregnancy or postpartum. For this study, a representative sample of infants enrolled in WIC was desired. Because the associations between WIC prenatal support and education and feeding practices and behaviors are substantively important to this study, the sample needed to include both women enrolling their children prenatally and women enrolling their children postnatally. For prenatal WIC enrollees, we attempted to complete a prenatal interview with the mother prior to the child's birth. This paper describes the TLS approach used and the challenges addressed in implementation of the sample design and selection for the WIC ITFPS-2. Our approach generated a probability sample (subject to site geographic and size exclusions) using a stratified, multistage design, but there were challenges at each stage of selection. First, a WIC site was selected, and then newly enrolled WIC participants were sampled within selected sites during predetermined recruitment windows based on the site's average flow of new WIC enrollees. We discuss issues faced, including overcoming incomplete lists of individual WIC sites and discrepancies between projected new WIC enrollment counts and actual flow of new WIC enrollments during the recruitment period.

The negative effects of internalized homonegativity on sexual satisfaction: dyadic effects and gender-based differences in Chile

Heterosexism is not only expressed through sexual prejudice as an external stressor, but also as an internalized rejection toward one's own (and others') sexually diverse identity. That is, lesbian women and gay men themselves internalize negative societal attitudes toward their sexual orientation and identity-a phenomenon called internalized homonegativity. A wealth of research shows that internalized homonegativity negatively affects the health and social adjustment of gay and lesbian people. However, the literature has documented this trend from an individual (over a dyadic) perspective, and largely among gay (over lesbian) samples. To address this oversight, we analyzed data from 210 gay and lesbian couples in Chile to examine both actor and partner effects of internalized homonegativity on their sexual satisfaction. Results from moderation analyses from an actor-partner interdependence model (APIM) approach show that partners' internalized homonegativity negatively affects actor sexual satisfaction, a pattern significantly moderated by gender; that is, only observed among lesbian couples. Our results further demonstrated that these effects hold above and beyond the actor and partner effects of age and relationship satisfaction, as well as relationship length. These results are consistent with the broader literature, which discusses the specific features of internalized homonegativity in lesbian women, characterized-among other aspects-by restrictive social demands over their sexuality. Accordingly, our findings highlight the deleterious relational consequences of internalized homonegativity and offer a relevant empirical contribution to the understanding of specific minority stress dynamics among lesbian women.

Mental Health and Life Satisfaction on Chilean Gay Men and Lesbian Women: The Role of Perceived Sexual Stigma, Internalized Homophobia, and Community Connectedness

The Minority Stress Model has proposed that connectedness to a specific minority community may be a protective factor for stigmatized groups. This study evaluated the mediational role of connectedness with the gay men's and lesbian women's community on the relationship between two minority stressors (internalized homophobia and perceived sexual stigma) with anxiety-depressive symptomatology and life satisfaction. The sample consisted of 467 Chilean self-identified as gay men (57%) and lesbian women (43%). Results revealed that the two minority stressors were associated with anxiety-depressive symptomatology, but only internalized homophobia was associated with life satisfaction. The mediation hypothesis was partially supported by the relationship between internalized homophobia and life satisfaction. Unexpectedly, we found a negative association between connectedness with the gay men's and lesbian women's community and life satisfaction. This finding introduces a view that contrasts with the literature, which proposes that connectedness with the specific community would be a protective factor against sexual stigma.

Hoping for a Better Future during COVID-19: How Migration Plans Are Protective of Depressive Symptoms for Haitian Migrants Living in Chile

This paper explores the migration experiences, perceived COVID-19 impacts, and depression symptoms among Haitian migrants living in Santiago, Chile. Ninety-five participants from eight neighborhoods with a high density of Haitian migrants were recruited. Descriptive statistics, univariate analysis, and logistic regression analysis were conducted. Chi-squared tests were used to confirm univariate results. We found that 22% of participants had major depressive symptoms based on the CESD-R-20 scale, 87% reported major life changes due to COVID-19, and 78% said their migration plans had changed due to the pandemic. Factors associated with more depressive symptoms were being in debt (OR = 3.43) and experiencing discrimination (ORs: 0.60 to 6.19). Factors associated with less odds of depressive symptoms were social support (ORs: 0.06 to 0.25), change in migration plans due to COVID-19 (OR = 0.30), and planning to leave Chile (OR = 0.20). After accounting for relevant factors, planning to leave Chile is significantly predictive of fewer symptoms of depression. Haitian migrants living in Chile had a high prevalence of depression. Planning to leave Chile was a significant protector against depressive symptoms. Future studies should explore how nuanced experiences of uncertainty play out in migrants' lives, mental well-being, and planning for their future.

Respondent-Driven Sampling: a Sampling Method for Hard-to-Reach Populations and Beyond

Purpose of Review

We provided an overview of sampling methods for hard-to-reach populations and guidance on implementing one of the most popular approaches: respondent-driven sampling (RDS).

Recent Findings

Limitations related to generating a sampling frame for marginalized populations can make them “hard-to-reach” when conducting population health research. Data analyzed from non-probability-based or convenience samples may produce estimates that are biased or not generalizable to the target population. In RDS and time-location sampling (TLS), factors that influence inclusion can be estimated and accounted for in an effort to generate representative samples. RDS is particularly equipped to reach the most hidden members of hard-to-reach populations.

Summary

TLS, RDS, or a combination can provide a rigorous method to identify and recruit samples from hard-to-reach populations and more generalizable estimates of population characteristics. Researchers interested in sampling hard-to-reach populations should expand their toolkits to include these methods.

Comparing recruitment strategies to engage hard-to-reach men who have sex with men living with HIV with unsuppressed viral loads in four US cities: Results from HPTN 078

Introduction

There is an urgent need to identify men who have sex with men (MSM) living with HIV with unsuppressed viral loads to prevent transmission. Though respondent‐driven sampling (RDS) is traditionally used for hard‐to‐reach populations, we compare how RDS and direct recruitment (DR) perform in identifying MSM living with HIV with unsuppressed viral loads and identifying MSM with socio‐demographics characteristic of hard‐to‐reach populations.

Methods

This is a cross‐sectional analysis among 1305 MSM who were recruited from March 2016 to December 2017 for a case management intervention trial (HPTN 078). We recruited participants across four cities using RDS and DR methods: Birmingham, AL; Atlanta, GA; Baltimore, MD; and Boston, MA. Participants completed a socio‐demographic questionnaire and underwent HIV testing. We compare the proportion of MSM with HIV and unsuppressed viral loads (HIV RNA ≥ 1000 copies/ml) based on recruitment method using Pearson chi‐square tests. We also compare differences in race, income, healthcare coverage, education, sexual orientation, hidden sexuality and comfort with participating in the LGBT community between recruitment methods and perform non‐parametric trend tests to see how demographics change across RDS recruitment waves.

Results

RDS recruited 721 men (55.2%) and DR yielded 584 men (44.8%). Overall, 69% were living with HIV, of whom 18% were not virally suppressed. HIV prevalence was higher among those recruited via DR (84%) compared to RDS (58%), p < 0.0001. Twenty per cent of DR recruits were not virally suppressed compared to 15% of RDS, though this was not significant. DR yielded a significantly higher proportion of Black participants and those with less than a high school diploma. The prevalence of low income, no healthcare coverage, bisexuality and hidden sexuality increased across RDS waves.

Conclusions

DR was more efficient in identifying MSM living with HIV with unsuppressed viral loads; however, there was a higher proportion of hard‐to‐reach MSM who were low income, lacked health coverage, were bisexual and were not open with their sexuality in deeper waves of RDS. Researchers should consider supplementing RDS recruitment with DR efforts if aiming to identify MSM with unsuppressed viral loads via RDS.

A comparison of the effectiveness of respondent-driven and venue-based sampling for identifying undiagnosed HIV infection among cisgender men who have sex with men and transgender women in Tijuana, Mexico

BACKGROUND

Efforts to increase HIV testing, diagnosis and care are critical to curbing HIV epidemics among cisgender men who have sex with men (MSM) and transgender women (TW) in low- and middle-income countries (LMIC). We compared the effectiveness of respondent-driven sampling (RDS) and venue-based sampling (VBS) for identifying previously undiagnosed HIV infection among MSM and TW in Tijuana, Mexico.

METHODS

Between March 2015 and December 2018, we conducted RDS within the social networks of MSM and TW and VBS at venues frequented by MSM and TW to socialize and meet sexual partners. Those reached by RDS/VBS who reported at least 18 years of age, anal sex with MSM or TW, and no previous HIV diagnosis were eligible for HIV testing.

RESULTS

Of those screened following recruitment via RDS (N = 1232; 98.6% MSM; 1.3% TW), 60.8% (749/1232) were eligible for HIV testing and 97.5% (730/749) were tested for HIV infection, which led to the identification of 36 newly diagnosed HIV infections (4.9%). Of those screened following recruitment via VBS (N = 2560; 95.2% MSM; 4.6% TW), 56.5% (1446/2560) were eligible for HIV testing and 92.8% (1342/1446) were tested for HIV infection, which led to the identification of 82 newly diagnosed HIV infections (6.1%). The proportion of new HIV diagnoses did not differ by recruitment method (ratio = 0.81, 95% confidence interval: 0.55 to 1.18). Compared to those recruited via RDS, those tested following recruitment via VBS were younger, more likely to identify as gay, and more likely to identify as TW. Compared to those recruited via VBS, those newly diagnosed with HIV infection following recruitment via RDS reported higher levels of internalized stigma and were more likely to report injection drug use and a history of deportation from the United States.

CONCLUSIONS

Despite RDS and VBS being equally effective for identifying undiagnosed HIV infection, each recruitment method reached different subgroups of MSM and TW in Tijuana. Our findings suggest that there may be benefits to using both RDS and VBS to increase the identification of previously undiagnosed HIV infection and ultimately support HIV care engagement among MSM and TW in Mexico and other similar LMIC.

Romantic Attachment and Relationship Satisfaction in Gay Men and Lesbians in Chile

Attachment theory has proven to be a solid framework for understanding couple bonds, but research focused on same-sex relationships among gay men and lesbian women from Latin America remains limited. The purpose of this study was to examine the association between romantic attachment and relationship satisfaction in a sample of Chilean gay men and lesbian women. A snowball sampling was used. The final sample consisted of 259 individuals involved in a same-sex couple relationship, ranging from 18 to 66 years of age (M = 27.2, SD = 6.8) for gay men and 18 to 57 years of age (M = 28.6, SD = 8.1) for lesbian women. Our hypotheses were partially supported, as there was a negative association between attachment avoidance and relationship satisfaction, but not between attachment anxiety and relationship satisfaction. We did not find a gender moderating effect. These findings may contribute to the understanding of lesbian and gay people in a same-sex couples relationship from an attachment theory perspective.

Sex work, discrimination, drug use and violence: a pattern for HIV risk among transgender sex workers compared to MSM sex workers and other MSM in Guatemala

The risk of HIV infection is higher among transgender women and cisgender men who have sex with men (MSM) compared to the general population due in part to social and contextual factors. This study aimed to determine the prevalence and association of alcohol and drug abuse, discrimination and violence among transgender sex workers compared to cisgender male sex workers and cisgender men who had not received money for sex in Guatemala City. In 2010, transgender women and cisgender men who had had sex with men or transgender women were recruited into a cross-sectional behavioural survey. Among transgender women, 86% received money for sex in the past year. Transgender sex workers were more likely to use drugs and binge drink, three times as likely to be discriminated against and eight times as likely to be forced to have sex compared to non-sex worker men. Male sex workers were twice as likely to use illicit drugs or experience physical violence and six times as likely to experience forced sex compared to non-sex worker men. Transgender and male sex workers would benefit from harm reduction for substance use, violence prevention, response and strategies to mitigate discrimination.

Injection and Heterosexual Risk Behaviors for HIV Infection Among Non-gay Identifying Men Who Have Sex with Men and Women

Non-gay identifying men who have sex with men and women (MSMW) are an important subgroup of men who have sex with men (MSM) and have been underrepresented in studies of MSM that only use gay venues to draw their samples. We assessed heterosexual and drug use risks of MSMW who use drugs in a sample of male entrants to the Mount Sinai Beth Israel drug treatment programs from 2005 to 2018. Blood samples were collected and tested for HIV and HSV-2 infections. Among HIV seronegative participants, MSMW had significantly greater odds of sharing used needles with others, and reporting unprotected sex with female casual partners and female commercial sex partners, compared to their counterparts who reported sex with women exclusively (MSWE). Although not recruited from gay venues, MSMW had a significantly higher HIV prevalence than MSWE (23% vs. 10%, p < 0.001). Interventions that are specifically tailored to HIV prevention among MSMW are needed to ameliorate the prevalence of HIV risks and infection.

Factors associated with HIV testing among men who have sex with men in Guatemala City

Although men who have sex with men (MSM) have the highest human immunodeficiency virus (HIV) prevalence in Guatemala, prevention efforts have been focused on other vulnerable populations. Respondent-driven sampling was used to recruit 444 MSM in Guatemala City to explore factors related to HIV testing among MSM. About 56% of participants reported HIV testing in the past 12 months, which was associated with a public MSM status (adjusted odds ratio (AOR) 2.08; 95% CI 1.02-4.26), participating in peer HIV prevention intervention (AOR 3.71; 95% CI 1.86-7.43), having at least one casual male partner (AOR 2.16; 95% CI 1.11-4.20), and practicing only insertive anal sex (AOR 3.35; 95% CI 1.59-7.09). Men with comprehensive HIV knowledge (AOR 2.63; 95% CI 1.38-5.02) were also more likely to have been tested. Further interventions in Guatemala targeting the most hidden MSM are needed.

Population-based assessment of health, healthcare utilisation, and specific needs of Syrian migrants in Germany: what is the best sampling method?

Background

Studies elucidating health-related information and special needs of Syrian migrants living in Germany are urgently required. However, data is scarce and finding appropriate sampling strategies to obtain representative results is challenging. In order to increase survey response in hard-to-reach populations, new methods were developed. One of them is respondent-driven sampling (RDS), a network sampling technique. We aimed to assess if respondent-driven sampling is a better approach to recruit Syrian migrants for health research than classical random sampling via the population registry.

Methods

A cross-sectional study was conducted in Munich between April and June 2017 inviting adults (18+ years) born in Syria to answer an online questionnaire asking for sociodemographic and health-related information. Recruitment of participants was done using a) random sampling via the population registry (PR) and b) RDS. The two study populations recruited via respondent-driven sampling and the population registry were compared to a sample drawn from the population registry with respect to gender and citizenship. In addition, the two study populations were compared to each other regarding self-reported health status, healthcare utilisation, lifestyle factors, social network size, and acculturation.

Results

Of 374 persons randomly drawn from the population registry, 49 individuals answered the questionnaire completely (response: 13.1%) while via RDS 195 participants were recruited by 16 seeds. More persons possessed German citizenship in the total sample (20.5, 95% CI: 16.6 to 24.8%) and in the PR study population (28.6, 95% CI: 16.6 to 43.3%) than in the study population (0.5, 95% CI: 0.1 to 1.5%). Participants recruited via the population registry were older, smoked less, reported more often to hold a university degree, and indicated a higher prevalence of chronic diseases, more frequent healthcare utilisation, higher scores of acculturation as well as a larger social network compared to the study population obtained via RDS.

Conclusions

Response was very low in the PR sample. The number of participants recruited via RDS was larger and led to a study population with substantially different characteristics. Our study thus indicates that RDS is a useful way to gain access to specific subgroups that are hard to reach via traditional random sampling.

Electronic supplementary material

The online version of this article (10.1186/s12874-018-0652-1) contains supplementary material, which is available to authorized users.

Incorporation of Social Determinants of Health in the Peer-Reviewed Literature: A Systematic Review of Articles Authored by the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention

OBJECTIVES

Social determinants of health (SDHs) are the complex, structural, and societal factors that are responsible for most health inequities. Since 2003, the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP) has researched how SDHs place communities at risk for communicable diseases and poor adolescent health. We described the frequency and types of SDHs discussed in articles authored by NCHHSTP.

METHODS

We used the MEDLINE/PubMed search engine to systematically review the frequency and type of SDHs that appeared in peer-reviewed publications available in PubMed from January 1, 2009, through December 31, 2014, with a NCHHSTP affiliation. We chose search terms to identify articles with a focus on the following SDH categories: income and employment, housing and homelessness, education and schooling, stigma or discrimination, social or community context, health and health care, and neighborhood or built environment. We classified articles based on the depth of topic coverage as "substantial" (ie, one of ≤3 foci of the article) or "minimal" (ie, one of ≥4 foci of the article).

RESULTS

Of 862 articles authored by NCHHSTP, 366 (42%) addressed the SDH factors of interest. Some articles addressed >1 SDH factor (366 articles appeared 568 times across the 7 categories examined), and we examined them for each category that they addressed. Most articles that addressed SDHs (449/568 articles; 79%) had a minimal SDH focus. SDH categories that were most represented in the literature were health and health care (190/568 articles; 33%) and education and schooling (118/568 articles; 21%).

CONCLUSIONS

This assessment serves as a baseline measurement of inclusion of SDH topics from NCHHSTP authors in the literature and creates a methodology that can be used in future assessments of this topic.

Age bias in survey sampling and implications for estimating HIV prevalence in men who have sex with men: insights from mathematical modelling

Respondent-driven sampling (RDS) is widely used to estimate HIV prevalence in men who have sex with men (MSM). Mathematical models that are calibrated to these data may be compromised if they fail to account for selection biases in RDS surveys. To quantify the potential extent of this bias, an agent-based model of HIV in South Africa was calibrated to HIV prevalence and sexual behaviour data from South African studies of MSM, first reweighting the modelled MSM population to match the younger age profile of the RDS surveys (age-adjusted analysis) and then without reweighting (unadjusted analysis). The model estimated a median HIV prevalence in South African MSM in 2015 of 34.6% (inter-quartile range (IQR): 31.4-37.2%) in the age-adjusted analysis, compared with 26.1% (IQR: 24.1-28.4%) in the unadjusted analysis. The median lifetime risk of acquiring HIV in exclusively homosexual men was 88% (IQR: 82-92%) in the age-adjusted analysis, compared with 76% (IQR: 64-85%) in the unadjusted analysis. These results suggest that RDS studies may under-estimate the exceptionally high HIV prevalence rates in South African MSM because of over-sampling of younger MSM. Mathematical models that are calibrated to these data need to control for likely over-sampling of younger MSM.

The Where and How for Reaching Transgender Women and Men Who Have Sex with Men with HIV Prevention Services in Guatemala

This study aims to describe the transgender women and men who have sex with men (MSM) missed through venue-based sampling and illustrate how data on venues can be used to prioritize service delivery. Respondent-driven sampling (RDS) and time-location sampling (TLS) were used concurrently in 2010 for behavioral surveillance among MSM and transgender women in Guatemala City. RDS recruits who did not frequent venues (n = 106) were compared to TLS recruits (n = 609). TLS participants recruited at different types of venues were compared. RDS recruits who did not frequent venues were less educated, less likely to identify as gay, more likely to have concurrent partners and female sexual partners. Participants recruited at NGOs, saunas, hotels, streets and parks had more partners, were more likely to receive money for sex or have concurrent partners. Prevention programs for MSM and transgender women should characterize social venues and people that frequent them and improve service coverage through venues and social networks.

HIV serostatus knowledge and serostatus disclosure with the most recent anal intercourse partner in a European MSM sample recruited in 13 cities: results from the Sialon-II study

Background

Knowledge of HIV status can be important in reducing the risk of HIV exposure. In a European sample of men-who-have-sex-with-men (MSM), we aimed to identify factors associated with HIV serostatus disclosure to the most recent anal intercourse (AI) partner. We also aimed to describe the impact of HIV serostatus disclosure on HIV exposure risks.

Methods

During 2013 and 2014, 4901 participants were recruited for the bio-behavioural Sialon-II study in 13 European cities. Behavioural data were collected with a self-administered paper questionnaire. Biological specimens were tested for HIV antibodies. Factors associated with HIV serostatus disclosure with the most recent AI partner were examined using bivariate and multilevel multivariate logistic regression analysis. We also describe the role of serostatus disclosure for HIV exposure of the most recent AI partner.

Results

Thirty-five percent (n = 1450) of the study participants reported mutual serostatus disclosure with their most recent AI partner or disclosed having HIV to their partner. Most of these disclosures occurred between steady partners (74%, n = 1077). In addition to the type of partner and HIV diagnosis status, other factors positively associated with HIV serostatus disclosure in the multilevel multivariate logistic regression model were recent testing, no condom use, and outness regarding sexual orientation. Disclosure rates were lowest in three south-eastern European cities.

Following condom use (51%, n = 2099), HIV serostatus disclosure (20%, n = 807) was the second most common prevention approach with the most recent AI partner, usually resulting in serosorting. A potential HIV exposure risk for the partner was reported by 26% (111/432) of HIV antibody positive study participants. In 18% (20/111) of exposure episodes, an incorrect HIV serostatus was unknowingly communicated. Partner exposures were equally distributed between steady and non-steady partners.

Conclusions

The probability of HIV exposure through condomless AI is substantially lower after serostatus disclosure compared to non-disclosure. Incorrect knowledge of one’s HIV status contributes to a large proportion of HIV exposures amongst European MSM. Maintaining or improving condom use for anal intercourse with non-steady partners, frequent testing to update HIV serostatus awareness, and increased serostatus disclosure particularly between steady partners are confirmed as key aspects for reducing HIV exposures amongst European MSM.

Electronic supplementary material

The online version of this article (10.1186/s12879-017-2814-x) contains supplementary material, which is available to authorized users.

High acceptability of rapid HIV self-testing among a diverse sample of MSM from Buenos Aires, Argentina

INTRODUCTION

The objective of this study was to explore the acceptability of rapid HIV self-testing (RHST) among men who have sex with men (MSM).

METHODS

During 2006-2009, a sample of 500 MSM was recruited through Respondent Driven Sampling for an HIV prevalence/incidence study. Attitude toward RHST was explored among HIV negative MSM. Data were weighted prior to analyses.

RESULTS

Participants reported they were likely to buy RHST (74%), test themselves more frequently than they currently do (77%), and that the procedure would simplify testing (70%). Furthermore, 71% reported they would probably use it alone, 66% would use it with a steady partner, and 56% with a friend/partner. While a majority acknowledged that RHST use would deprive them of receiving counseling (61%), 74% declared they would go for help if they tested positive; 57% would use an RHST in order to avoid condoms. Probability of use surpassed 70% among gay and non-gay identified MSM as well as those with and without a previous HIV test. Those likely to buy RHST were older (p = 0.025) and more likely to identify as gay (p = 0.036). A total of 17% said they would think about killing themselves and 9% would attempt suicide if they tested positive. These MSM were more likely to be younger (p<0.001), with lower mood level (p<0.001) and greater feelings of loneliness (p = 0.026).

CONCLUSIONS

The high acceptability of RHST found among MSM should encourage the authorities to consider the possibility of offering it for self-testing, as it can improve early diagnosis and prevention of future transmissions. However, further research is needed to understand how to best disseminate RHST among MSM who wish to use it and to offer support and linkage to care for those who test HIV-positive.

Relation between HIV status, risky sexual behavior, and mental health in an MSM sample from three Chilean cities

OBJECTIVE

To explore the association among HIV status; negative psychological symptoms (anxiety, depression, and hostility); and risky sexual behaviors (multiple sexual partners and unprotected sexual intercourse) in a Chilean sample of men who have sex with men (MSM).

METHODS

This study had a cross-sectional design and a sample of 325 MSM whose ages ranged from 18 to 64 years (mean: 30.8; standard deviation: 9.8). Association tests (chi-squared) and group mean comparisons (Student's t-tests and F-tests) were performed.

RESULTS

No statistically significant differences were found for condom use or for the number of sexual partners between HIV-positive men and those who are not infected. In both groups, about 50% reported sexual encounters without condom use in the past six months. There were statistically significant differences in symptoms associated with depression between the two groups.

CONCLUSIONS

These results reveal the need to strengthen messages about the importance of condom use, as the only way to prevent HIV, and as a means of preventing HIV infection and reinfection, in national prevention and self-care programs for sexually active subjects. More studies are needed in Latin America to advance HIV prevention efforts for the MSM population. The data generated by this study can be used to inform the development of HIV prevention programming strategies and interventions targeting the MSM population in Latin America.

Surveillance and response for high-risk populations: what can malaria elimination programmes learn from the experience of HIV?

To eliminate malaria, malaria programmes need to develop new strategies for surveillance and response appropriate for the changing epidemiology that accompanies transmission decline, in which transmission is increasingly driven by population subgroups whose behaviours place them at increased exposure. Conventional tools of malaria surveillance and response are likely not sufficient in many elimination settings for accessing high-risk population subgroups, such as mobile and migrant populations (MMPs), given their greater likelihood of asymptomatic infections, illegal risk behaviours, limited access to public health facilities, and high mobility including extended periods travelling away from home. More adaptive, targeted strategies are needed to monitor transmission and intervention coverage effectively in these groups. Much can be learned from HIV programmes’ experience with “second generation surveillance”, including how to rapidly adapt surveillance and response strategies to changing transmission patterns, biological and behavioural surveys that utilize targeted sampling methods for specific behavioural subgroups, and methods for population size estimation. This paper reviews the strategies employed effectively for HIV programmes and offers considerations and recommendations for adapting them to the malaria elimination context.

Subjective Wellbeing and Levels of Clinical Symptomatology in a Transwomen Sample and Men Who Have Sex With Men in Chile

This article examines the levels of subjective wellbeing (psychological and social wellbeing, subjective happiness, and satisfaction with life) and clinical symptomatology (anxiety, depression, somatization, hostility, and phobic anxiety) in a transwomen sample (n = 112). The sample was recruited through a snowball procedure in Chile (Santiago, Valparaíso, and Arica). Data obtained are compared to those from a group of men who have sex with men (MSM; n = 323). Results reveal statistically significant differences in the levels of happiness (t₍₁₅₇₎ = 2.16; p = .03; d = .25), satisfaction with life (t₍₁₅₄₎ = 3.90; p < .001; d = .47), and purpose in life (scale of psychological wellbeing; t₍₁₅₁₎ = 1.99; p .04; d = .24) reported by the two groups. The transwomen group shows the lowest scores in all dimensions. However, trans women report higher levels of social coherence (t₍₄₃₂₎ = -4.96; p < .001; d = .53) on the social wellbeing scale, compared to the MSM group. Regarding their levels of clinical symptomatology, trans women report higher levels of anxiety (t₍₁₆₃₎ = -6.67; p < .001; d = .78), depression (t₍₁₆₇₎ = -5.61; p < .001; d = .65), somatization (t₍₁₆₁₎ = -5.10; p < .001; d = .60), hostility (t₍₁₅₃₎ = -5.38; p < .001; d = .62), and phobic anxiety (t₍₁₆₄₎ = -6.70; p < .001; d = .80). Results are discussed on the basis of the context of each group.

System Justification's Opposite Effects on Psychological Wellbeing: Testing a Moderated Mediation Model in a Gay Men and Lesbian Sample in Chile

Those who adhere to system-justifying beliefs benefit from a palliative function that buffers negative effects on psychological wellbeing. This has been consistently observed for high-status groups, whereas for members of low-status groups, it remains rather unclear whether system justification exerts a positive or a negative effect. This study tested the palliative effect of system justification on symptoms of anxiety-depression in a gay men and lesbian sample (N = 467) in Chile. Results from moderated mediation analyses revealed that system justification beliefs buffer symptoms of anxiety and depression. However, system justification enhances anxious and depressive symptoms through internalized homonegativity; this mediation effect was significant for gay men. We pose that justifying the social order comprises two contradictory functions: system justification as a coping source and, otherwise, as a source of distress under conditions of in-group derogation, posing a threat to wellbeing among members of low-status groups (as observed in gay and lesbian individuals). Implications of the opposing effects and gender differences are further discussed in this study.

The ecology of sexual health of sexual minorities in Guatemala City

Guatemalan gay and bisexual men, men who have sex with men (MSM), and transgender persons carry disproportionate burden of HIV and other sexually transmitted infections compared with other Guatemalan subgroups. However, little is known about the determinants of sexual health to inform health promotion and disease prevention interventions among these sexual minorities. We sought to explore sexual health and HIV risk among Guatemalan sexual minorities, using a community-based participatory research approach. We conducted 8 focus groups (n = 87 participants total) and 10 individual in-depth interviews with gay and bisexual men, MSM, and transgender persons. Using constant comparison, an approach to grounded theory, we analyzed verbatim transcripts and identified 24 themes that we organized into five ecological factors influencing sexual health: intrapersonal (e.g. misconceptions about HIV transmission, low perceived susceptibility and lack of condoms use skills); interpersonal (e.g. family rejection and condom use as a barrier to intimacy); community (e.g. discrimination and stigma); institutional (e.g. limited access to health promotion resources); and public policy (e.g. perceived lack of provider confidentiality and anti-gay rhetoric). There is profound need for multiple-level interventions to ensure that Guatemalan sexual minorities have the knowledge and skills needed to reduce sexual risk. Interventions are warranted to increase social support among sexual minorities, reduce negative perspectives about sexual minorities, develop institutional resources to meet the needs of sexual minorities and reduce harmful anti-gay rhetoric. Understanding and intervening on the identified factors is especially important given that the health of Guatemalan sexual minorities has been to-date neglected.

Hard-to-reach populations of men who have sex with men and sex workers: a systematic review on sampling methods

BACKGROUND

In public health, hard-to-reach populations are often recruited by non-probabilistic sampling methods that produce biased results. In order to overcome this, several sampling methods have been improved and developed in the last years. The aim of this systematic review was to identify all current methods used to survey most-at-risk populations of men who have sex with men and sex workers. The review also aimed to assess if there were any relations between the study populations and the sampling methods used to recruit them. Lastly, we wanted to assess if the number of publications originated in middle and low human development (MLHD) countries had been increasing in the last years.

METHODS

A systematic review was conducted using electronic databases and a total of 268 published studies were included in the analysis.

RESULTS

In this review, 11 recruitment methods were identified. Semi-probabilistic methods were used most commonly to survey men who have sex with men, and the use of the Internet was the method that gathered more respondents. We found that female sex workers were more frequently recruited through non-probabilistic methods than men who have sex with men (odds = 2.2; p < 0.05; confidence interval (CI) [1.1-4.2]). In the last 6 years, the number of studies based in middle and low human development countries increased more than the number of studies based in very high and high human development countries (odds = 2.5; p < 0.05; CI [1.3-4.9]).

CONCLUSIONS

This systematic literature review identified 11 methods used to sample men who have sex with men and female sex workers. There is an association between the type of sampling method and the population being studied. The number of studies based in middle and low human development countries has increased in the last 6 years of this study.

A comparison between respondent-driven sampling and time-location sampling among men who have sex with men in Shenzhen, China

Men who have sex with men (MSM) are a key population for HIV control and prevention in China. It is difficult to acquire representative samples of this hidden population. Respondent-driven sampling (RDS), based on peer referral, and time-location sampling (TLS) based on random selection of venue-day-time periods, are among the most commonly used sampling methods. However, differences in HIV-related characteristics of MSM recruited by these two methods have not been fully evaluated. We compared sociodemographics, risk behaviors, utilization of HIV-related intervention services, and HIV/syphilis infection rates between samples of 621 RDS MSM and 533 TLS MSM in Shenzhen, China in 2010. We found that the HIV prevalence was comparable in RDS and TLS MSM. TLS recruited larger proportions of more marginalized MSM than RDS: MSM recruited by TLS were older, less educated and more likely to be migrants (without Shenzhen hukou registration), to be non-gay identified and to engage in risky sexual behaviors. On the other hand, MSM recruited by TLS were more likely to have been covered by HIV-related intervention services. To conclude, in Shenzhen, TLS is more effective to reach the marginalized population of MSM. But because TLS can only reach MSM who physically attend venues and HIV-related intervention services are already commonly available at gay venues in Shenzhen, RDS is more informative for allocating prevention efforts than TLS. Furthermore, researchers and public health authorities should take into account the different sample compositions of RDS and TLS and apply sampling methods consistently when evaluating trends over time.

High HIV Prevalence among Men who have Sex with Men in a Time-Location Sampling Survey, São Paulo, Brazil

We conducted a time-location sampling sero-behavioral surveillance survey of men who have sex with men (MSM) in São Paulo, Brazil, the largest city in Latin America and the Southern Hemisphere (N = 1,217 interviewed with serological results for 771). HIV prevalence was 15.4 % (95 % CI 11.6-20.1), with only 45.8 % previously aware of their infection. HIV prevalence achieved 6.4 % among youth 18-24 years and was higher among MSM with lower socio-economic status. In multivariate analysis, correlates of HIV were older age, gay identity, lower socio-economic status, social networks with HIV-positive MSM, receptive anal sex, and internet sex partners. Policy change towards increasing avenues for HIV testing coupled with antiretroviral treatment regardless of CD4 count or stage of disease stand to benefit the MSM community if scaled up fast enough.

Sampling Males Who Inject Drugs in Haiphong, Vietnam: Comparison of Time-Location and Respondent-Driven Sampling Methods

Accurate measurements of HIV prevalence and associated risk factors among hidden and high-risk groups are vital for program planning and implementation. However, only two sampling methods are purported to provide representative estimates for populations without sampling frames: time-location sampling (TLS) and respondent-driven sampling (RDS). Each method is subject to potential biases and questionable reliability. In this paper, we evaluate surveys designed to estimate HIV prevalence and associated risk factors among people who inject drugs (PWID) sampled through TLS versus RDS. In 2012, males aged ≥16 years who reported injecting drugs in the previous month and living in Haiphong, Vietnam, were sampled using TLS or RDS. Data from each survey were analyzed to compare HIV prevalence, related risk factors, socio-demographic characteristics, refusal estimates, and time and expenditures for field implementation. TLS (n = 432) and RDS (n = 415) produced similarly high estimates for HIV prevalence. Significantly lower proportions of PWID sampled through RDS received methadone treatment or met an outreach worker. Refusal estimates were lower for TLS than for RDS. Total expenditures per sample collected and number of person-days of staff effort were higher for TLS than for RDS. Both survey methods were successful in recruiting a diverse sample of PWID in Haiphong. In Vietnam, surveys of PWID are conducted throughout the country; although the refusal estimate was calculated to be much higher for RDS than TLS, RDS in Haiphong appeared to sample PWID with less exposure to services and required fewer financial and staff resources compared with TLS.

HIV Prevalence and Awareness of Positive Serostatus Among Men Who Have Sex With Men and Transgender Women in Bogotá, Colombia

OBJECTIVES

We estimated HIV prevalence among men who have sex with men (MSM) and transgender women in Bogotá, Colombia, and explored differences between HIV-positive individuals who are aware and unaware of their serostatus.

METHODS

In this cross-sectional 2011 study, we used respondent-driven sampling (RDS) to recruit 1000 MSM and transgender women, who completed a computerized questionnaire and received an HIV test.

RESULTS

The RDS-adjusted prevalence was 12.1% (95% confidence interval [CI] = 8.7, 15.8), comparable to a previous RDS-derived estimate. Among HIV-positive participants, 39.7% (95% CI = 25.0, 54.8) were aware of their serostatus and 60.3% (95% CI = 45.2, 75.5) were unaware before this study. HIV-positive-unaware individuals were more likely to report inadequate insurance coverage, exchange sex (i.e., sexual intercourse in exchange for money, goods, or services), and substance use than other participants. HIV-positive-aware participants were least likely to have had condomless anal intercourse in the previous 3 months. Regardless of awareness, HIV-positive participants reported more violence and forced relocation experiences than HIV-negative participants.

CONCLUSIONS

There is an urgent need to increase HIV detection among MSM and transgender women in Bogotá. HIV-positive-unaware group characteristics suggest an important role for structural, social, and individual interventions.

Sampling methodologies for epidemiologic surveillance of men who have sex with men and transgender women in Latin America: an empiric comparison of convenience sampling, time space sampling, and respondent driven sampling

Alternatives to convenience sampling (CS) are needed for HIV/STI surveillance of most-at-risk populations in Latin America. We compared CS, time space sampling (TSS), and respondent driven sampling (RDS) for recruitment of men who have sex with men (MSM) and transgender women (TW) in Lima, Peru. During concurrent 60-day periods from June-August, 2011, we recruited MSM/TW for epidemiologic surveillance using CS, TSS, and RDS. A total of 748 participants were recruited through CS, 233 through TSS, and 127 through RDS. The TSS sample included the largest proportion of TW (30.7 %) and the lowest percentage of subjects who had previously participated in HIV/STI research (14.9 %). The prevalence of newly diagnosed HIV infection, according to participants' self-reported previous HIV diagnosis, was highest among TSS recruits (17.9 %) compared with RDS (12.6 %) and CS (10.2 %). TSS identified diverse populations of MSM/TW with higher prevalences of HIV/STIs not accessed by other methods.

Epidemiological challenges to the assessment of HIV burdens among key populations: respondent-driven sampling, time-location sampling and demographic and health surveys

PURPOSE OF REVIEW

Measuring the burden of HIV among key populations is subject to many challenges. Sufficient quantities of valid HIV prevalence and programme coverage data are required to effectively respond to the epidemic.

RECENT FINDINGS

Ability to validate exposure to unprotected sex through the innovative use of prostate-specific antigen provides confirmation of condom use. A new weighting scheme based on frequency of venue attendance for time location samples should improve validity of data obtained with this method. Two new proportion estimators, new diagnostic methods, a new population size estimator and new analysis software will provide more robust results from respondent-driven sampling (RDS).

SUMMARY

Analytical advances have improved the potential quality of results from surveys using time location and RDS. However, data from sufficient numbers of sites over sufficient number of years are still needed to provide clear national pictures of distribution and trends of HIV infection.

Características sociodemográficas, bienestar subjetivo y homofobia en una muestra de hombres gay en tres ciudades chilenas

Este artículo describe y caracteriza sociodemográficamente a una muestra de hombres gay en tres ciudades de Chile. Además, describe sus niveles de homofobia y bienestar subjetivo. Mediante un muestreo en cadena tipo bola de nieve se encuestó a 325 hombres que se autodefinieron como gay. Entre los principales hallazgos se encontró altos niveles de discriminación y victimización percibida. Además en comparación con estudios similares efectuados en el país, los encuestados presentan niveles mayores de bienestar social. La edad de los encuestados aporta diferencias para los niveles de bienestar social y no para las otras medidas. También, las personas con estudios superiores reportan mayores niveles de victimización y un mayor impacto vital de las situaciones de discriminación. Asimismo, si bien las personas que residen en Santiago reportan un mayor impacto relativo de los hechos de agresión, presentan mejores niveles de bienestar social y felicidad en comparación a las personas que viven en otras regiones.