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.
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Beyrer C, Baral SD, van Griensven F, et al. Global epidemiology of HIV infection in men who have sex with men. Lancet. 2012;380(9839):367–77.
Hall HI, Geduld J, Boulos D, et al. Epidemiology of HIV in the United States and Canada: current status and ongoing challenges. JAIDS. 2009;51(Suppl 1):S13–20.
BC Centre for Disease Control. HIV in British Columbia: annual surveillance report 2014. http://www.bccdc.ca/util/about/annreport/default.htm. Published November 2015. Accessed May 15, 2016.
Hughes AJ, Saxton PJ. Geographic micro-clustering of homosexual men: implications for research and social policy. Soc Policy J N Z. 2006;28:158–78.
Statistics Canada. Health care use among gay, lesbian and bisexual Canadians. Vol 19. Health reports. http://www.statcan.gc.ca/pub/82-003-x/2008001/article/10532-eng.htm. Published 2008. Accessed 7 June 2016.
Heckathorn DD. Respondent-driven sampling: a new approach to the study of hidden populations. Soc Probl. 1997;44(2):174–99.
Heckathorn DD, Semaan S, Broadhead RS, Hughes JJ. Extensions of respondent-driven sampling: a new approach to the study of injection drug users aged 18–25. AIDS Behav. 2002;6(1):55–67.
Heckathorn DD. Respondent-driven sampling II: deriving valid population estimates from chain-referral samples of hidden populations. Soc Probl. 2002;49(1):11–34.
Laumann EO, Gagnon JH, Michael RT, Michaels S. The Social Organization of Sexuality. Chicago, IL: University of Chicago Press; 1994.
Blair J. A probability sample of gay urban males: the use of two-phase adaptive sampling. J Sex Res. 1999;36(1):39–44.
Meyer IH, Wilson PA. Sampling lesbian, gay, and bisexual populations. J Couns Psychol. 2009;56(1):23.
Yang Q, Boulos D, Yan P, et al. Estimates of the number of prevalent and incident human immunodeficiency virus (HIV) infections in Canada, 2008. Can J Public Health. 2010;101(6):486–90.
Purcell DW, Johnson CH, Lansky A, et al. Estimating the population size of men who have sex with men in the United States to obtain HIV and syphilis rates. Open AIDS J. 2012;6(1):98–107.
Sabin K, Zhao J, Garcia Calleja JM, et al. Availability and quality of size estimations of female sex workers, men who have sex with men, people who inject drugs and transgender women in low- and middle-income countries. PLoS One. 2016;11(5):e0155150.
Luan R, Zeng G, Zhang D, et al. A study on methods of estimating the population size of men who have sex with men in Southwest China. Eur J Epidemiol. 2005;20(7):581–5.
Paz-Bailey G, Jacobson JO, Guardado ME, et al. How many men who have sex with men and female sex workers live in El Salvador? Using respondent-driven sampling and capture-recapture to estimate population sizes. Sex Transm Infect. 2011;87(4):279–82.
Raymond HF, Bereknyei S, Berglas N, Hunter J, Ojeda N, McFarland W. Estimating population size, HIV prevalence and HIV incidence among men who have sex with men: a case example of synthesising multiple empirical data sources and methods in San Francisco. Sex Transm Infect. 2013;89(5):383–7.
Archibald CP, Jayaraman GC, Major C, Patrick DM, Houston SM, Sutherland D. Estimating the size of hard-to-reach populations: a novel method using HIV testing data compared to other methods. AIDS. 2001;15:S41.
Okal J, Geibel S, Muraguri N, et al. Estimates of the size of key populations at risk for HIV infection: men who have sex with men, female sex workers and injecting drug users in Nairobi, Kenya. Sex Transm Infect. 2013;89(5):366–71.
Holmberg SD. The estimated prevalence and incidence of HIV in 96 large US metropolitan areas. Am J Public Health. 1996;86(5):642–54.
Pouget ER, Friedman SR, Cleland CM, et al. Estimates of the population prevalence of injection drug users among hispanic residents of large US metropolitan areas. J Urban Health. 2012;89(3):527–64.
Tempalski B, Lieb S, Cleland CM, et al. HIV prevalence rates among injection drug users in 96 large US metropolitan areas, 1992–2002. J Urban Health. 2009;86(1):132–54.
Statistics Canada. Canadian Community Health Survey (CCHS)—annual component: user guide 2012 and 2011–12 microdata files. Statistics Canada: Ottawa, ON; 2013.
Moore DM, Cui Z, Lachowsky N, et al. HIV community viral load and factors associated with elevated viremia among a community-based sample of men who have sex with men in Vancouver, Canada. J Acquir Immune Defic Syndr. 2016;72(1):87–95.
Respondent-Driven Sampling Analysis Tool (RDSAT) Version 7.1. Ithaca, NY: Cornell University; 2012.
Statistics Canada. Census dictionary. Ottawa, Canada http://www12.statcan.gc.ca/census-recensement/2011/ref/dict/geo049a-eng.cfm. Published 2011. Accessed 15 May 2016.
Sarafin C, Simard M, Thomas S. A review of the weighting strategy for the Canadian Community Health Survey. In: St John’s; 2007. Presented as part of the Statistical Society of Canada conference; 2007; St. John’s, Newfoundland.
Quaye S, Fisher Raymond H, Atuahene K, et al. Critique and lessons learned from using multiple methods to estimate population size of men who have sex with men in Ghana. AIDS Behav. 2015;19(1):S16–23.
Khalid FJ, Hamad FM, Othman AA, et al. Estimating the number of people who inject drugs, female sex workers, and men who have sex with men, Unguja Island, Zanzibar: results and synthesis of multiple methods. AIDS Behav. 2014;18(1):25–31.
Lee MD, Zhang S, Shi J. The wisdom of the crowd playing The Price Is Right. Mem Cogn. 2011;39(5):914–23.
UNAIDS/WHO Working Group on HIV/AIDS/STI Surveillance. Guidelines on estimating the size of populations most at risk to HIV. 2010:1–51.
Statistics Canada. Visual census. https://www12.statcan.gc.ca/census-recensement/2011/dp-pd/vc-rv/index.cfm?Lang=ENG&VIEW=D&CFORMAT=jpg&GEOCODE=933&TOPIC_ID=2. Published October 2012. Accessed 15 May 2016.
Fenton KA, Johnson AM, McManus S, Erens B. Measuring sexual behaviour: methodological challenges in survey research. Sex Transm Infect. 2001;77(2):84–92.
Hottes TS, Ferlatte O, Gilbert M. Misclassification and undersampling of sexual minorities in population surveys. Am J Public Health. 2015;105(1):e5.
Berg N, Lien D. Same-sex sexual behaviour: US frequency estimates from survey data with simultaneous misreporting and non-response. Appl Econ. 2007;38(7):757–69.
Goldstein ND, Welles SL, Burstyn I. To be or not to be: Bayesian correction for misclassification of self-reported sexual behaviors among men who have sex with men. Epidemiology. 2015;26(5):637–44.
Ghanem KG, Hutton HE, Zenilman JM, Zimba R, Erbelding EJ. Audio computer assisted self interview and face to face interview modes in assessing response bias among STD clinic patients. Sex Transm Infect. 2005;81(5):421–5.
van Griensven F, Naorat S, Kilmarx PH, et al. Palmtop-assisted self-interviewing for the collection of sensitive behavioral data: randomized trial with drug use urine testing. Am J Epidemiol. 2006;163(3):271–8.
Lorenz J, Rauhut H, Schweitzer F, Helbing D. How social influence can undermine the wisdom of crowd effect. Proc Natl Acad Sci U S A. 2011;108(22):9020–5.
Floyd FJ, Bakeman R. Coming-out across the life course: implications of age and historical context. Arch Sex Behav. 2006;35(3):287–96.
Rainbow Health Ontario. LGBT research with secondary data. http://www.rainbowhealthontario.ca/wp-content/uploads/woocommerce_uploads/2012/10/LGBTQRESEARCHWITHSECONDARYDATA_E.pdf. Published August 2012. Accessed 10 Aug 2016.
Walker N, Stover J, Stanecki K, et al. The workbook approach to making estimates and projecting future scenarios of HIV/AIDS in countries with low level and concentrated epidemics. Sex Transm Infect. 2004;80(Suppl 1):i10–3.
Statistics Canada. Canadian Community Health Survey—annual component (CCHS). http://www23.statcan.gc.ca/imdb/p2SV.pl?Function=getSurvey&SDDS=3226#a2. Published June 24 2016. Accessed 10 July 2016.
Kendall C, Kerr LRFS, Gondim RC, et al. An empirical comparison of respondent-driven sampling, time location sampling, and snowball sampling for behavioral surveillance in men who have sex with men, Fortaleza, Brazil. AIDS Behav. 2008;12(Suppl 4):S97–S104.
Lansky A, Abdul-Quader AS, Cribbin M, et al. Developing an HIV behavioral surveillance system for injecting drug users: the National HIV Behavioral Surveillance System. Public Health Rep. 2007;122(Suppl 1):48–55.
This work was supported by the Canadian Institutes for Health Research  and the National Institute for Drug Abuse at the National Institutes for Health [R01DA031055]. We thank the research participants for sharing their important data with the Momentum Health Study. We also thank our community-based partners on the Momentum Health Study Community Advisory Board for their input in this work, including representatives from the Health Initiative for Men, YouthCO HIV & Hep C Society of BC, and Positive Living Society of BC. DMM is supported by a Scholar Award from the Michael Smith Foundation for Health Research.
• Men who have sex with men (MSM) are disproportionately affected by HIV globally, nationally in Canada, and locally in Vancouver, British Columbia.
• Lack of reliable population size estimates of MSM impedes effective implementation of health care services and limits our understanding of the HIV epidemic.
• Using diverse data sources and methods, our median estimate of the MSM population in Metro Vancouver was 27,183.
• The corresponding 2.9% proportion of MSM in the male census population of Metro Vancouver was similar to estimates from other jurisdictions.
• These findings will help support better public health planning and understanding of the HIV epidemic among MSM.
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Rich, A.J., Lachowsky, N.J., Sereda, P. et al. Estimating the Size of the MSM Population in Metro Vancouver, Canada, Using Multiple Methods and Diverse Data Sources. J Urban Health 95, 188–195 (2018). https://doi.org/10.1007/s11524-017-0176-8
- Population size
- Respondent-driven sampling