Table 3.

Studies using survey-based methods for estimating the number of men who have sex with men

Author, year	Country/State/City	Calculation	Source of data, years	Percent of MSM	Number of MSM	Sampling method	Characterization of study population
Archibald et al., 2001 (11)	Canada/Toronto, Montreal, Vancouver	Proportion of population reporting MSMa behavior in past year * male population over 15	1994 and 1997 CHMb survey	Not reported	Toronto=18,800, Montreal=18,500, Vancouver=7,000;	Population reporting MSM behavior in the past year/lifetime	Having had oral or anal intercourse with another man in the past year/lifetime
Purcell et al., 2012 (3)	United States	Applied the proportion of men reporting same-sex behavior in the past 5 years from literature search to United States census data	4 surveys, United States census data	3.9% of men engaged in same-sex behavior in past 5 years	4,791,262 MSM 13 and older in 2008	Probability samples, stratified cluster sample of US households	Men who reported same-sex behaviors or partners
Livak et al., 2013 (14)	United States/Illinois/Chicago	4.2% * young Black males in the South side of Chicago	NSFGc 2006–2010, 2010 US Census	4.2%	2,286	nationally representative multi-stage area probability sample survey from US households	Men who have had male–male sexual contact
Harris et al., 2013 (17)	United States	Percent from NHANESd * adult male population	NHANES 1999–2008	4.7%	3,555,568	civilian general household population	Men who ever had sex with a man
Hughes et al., 2017 (18)	United States/California/San Francisco	Means of the proportions of MSM by race were calculated from NHBSe 2004 and 2008/total adult male pop in San Francisco in 2006	NHBS; United States census	19.0% of adult males were MSM; 23.0% of all black adult males and 21.0% of all white males	58,605 in 2014, 14,452 were HIVf positive and 44,154 were HIV negative; 32,705 were white and 4,419 were black MSM in 2014	Data on MSM in San Francisco through standardized behavioral surveys	Not listed
Madeddu et al., 2006 (19)	Australia/Sydney	Applied percentage of same-sex attraction, experience, or identity from ASHRg for each postal code to the number of male residents of a similar age in those same postcode areas	2000/2001 Sydney Gay Community Periodic Survey, ASHR 2003, and Australian Household Census 2001	The proportion of men who identified as homosexual or bisexual ranged from 4.4% to 48.1%; 9.8% to 51.5% of men reported same-sex experiences during their lifetime; and 12.9% to 52.8% of men had ever experienced feelings of same-sex attraction	Selected inner east: identity-9,269, experience-12,979, attraction-13,508. Selected inner west: identity-3,464, experience-4,797, attraction-5,573	national representative population-based survey, participants were selected at random from the general population to participate in a telephone survey	Male participants who reported lifetime experience of sex with men, feelings of same-sex attraction during their lifetime, and/or a current homosexual or bisexual identity
Marcus et al., 2009 (20)	Germany	Based on the proportional regional distribution of survey participants and user profiles, assuming a total population size of 600,000	KABaSTIh-study 2006 and GMAi-2007-survey	2.6%	Not reported	Both were behavioural surveys among MSM, participants were recruited online (and offline too for GMA)	Male participants in the age group 20–50 years who reported sexual contacts with men in the previous 12 months
Mor et al., 2016 (21)	Israel	Projected the rates of study participants who reported sexual behavior, which included MSM, by the relevant Israeli population using the 2012 Statistical Abstract of Israel	Anonymous electronic questionnaire, Statistical Abstract of Israel	11.9% reported lifetime male sex encounters, 4.5% self-identified as gay and 3.7% as bisexual	94,176 in Israel and 33,839 in Tel-Aviv gay/bisexual	Random sample from representative sample of Jewish males aged 18–44 years who completed an anonymous electronic questionnaire	Same-sex sexual attraction; oral or anal intercourse with another man; self-identification
Okal et al., 2013 (22)	Kenya/Nairobi	Men 18 plus * estimate of prevalence in population from Caceres 2008	Caceres et al., 2008 and 2009 Nairobi census	1.2%	13,608 MSM		Had oral or anal sex with man
Oster et al., 2015 (23)	United States	Weighted prevalence estimate from NHANES by the population estimate	1999–2010 NHANES, Vintage 2011 file from the United States Census Bureau	4.7% of men had ever had male-male sex and 2.2% of men had male-male sex in the past 12 months	5,933,000 ever; 3,156,000 in past 12 months	Nationally representative sample of the civilian, noninstitutionalized population	Among men, having had oral or anal sex with another man during the past 12 months/ever
Prestage et al., 2008 (24)	Australia	Percentage of male participants in ASHR who reported a current homosexual or bisexual identity were applied to the number of adult male residents in the respective states from 2001 Australian Household Census	ASHR, 2001 Australian Household Census	2.5% overall; 3.0% in New South Wales; 2.3% in Victoria; 2.7% in Queensland	182,624 total; 74,420 in New South Wales; 41,990 in Victoria; 36,935 in Queensland	National representative population based survey, computer-assisted telephone interviews	Male participants in ASHR who reported a current homosexual or bisexual identity
Rich et al., 2018 (25)	Canada/Vancouver	Calculated median estimate for Vancouver urban core from 2 survey cycles	CCHSj 2011–2012 and 2013–2014 (median)	3.3% (median)	30,605	National population-based cross-sectional survey, interviewer-administered telephone surveys	Number of self-identified homosexual, gay, or bisexual men aged 18–59 years
Ruf et al., 2011 (26)	United Kingdom/London	Estimated inner London MSM proportion from NATSALk * 2008 inner London male population	British NATSAL 2000 and Greater London Authority population estimates 2008	5.5%	98,330 MSM aged 16–44 were living in Greater London in 2008	Probability sample survey of men and women using computer-assisted interviews	Partners of the same gender with whom the respondent had any form of genital contact
Shields et al., 2013 (27)	United States/California/San Francisco	(Unweighted count/population estimate)*100	2011 YRBSl	3.8% middle school students identify as LGBm; 1.7% as gay and lesbian and 2.1% as bisexual	Not reported	Stratified random sample of youth	“Which of the following best describes you?” “heterosexual (straight); gay or lesbian; bisexual; and not sure”
Veierod et al., 1997 (28)	Norway	Estimated proportion of subjects with homosexual experience from 2 postal surveys of general population (Lifetime or current prevalence/number of respondents) *100	Surveys sent by mail in 1987 and 1992	3.8% reported homosexual practice during lifetime and 1.2% during the past 3 years	188 lifetime; 57 past 3 years	Simple random samples drawn from the Central Population Registry, postal questionnaires sent	Had any form of sexual interaction with a person of the same gender as yourself ever/in past 3 years
Esie et al., 2018 (35)	United States	Answers to questions and total population surveyed	NHANES 1999–2014	Estimated prevalence of MSM-ever was 5.5%	Not reported	Cross-sectional surveys of the noninstitutionalized US population	Ever had any kind of sex with a man, including oral or anal
Geary et al., 2018 (36)	Britain	Estimates from NATSAL3 were applied to ONSn 2011 census population estimates	NATSAL 3, ONS	1.5% of 16–74 year old men self-identified as gay; 6.5% of men reported any same-sex sexual attraction; 5.5% of men reported same-sex sex ever	Not reported	Multistage clustered, stratified probability sample of residents in a private household in Britain were interviewed	I have felt sexually attracted to…; I have had some sexual experience…; Have you ever had any kind of sexual experience or sexual contact with a man?; Have you had sex with a man involving genital area/penis contact?
Zablotska et al., 2018 (37)	Australia	Number of men aged 16–69 years in Australia in mid-2015 * proportion of Australian men aged 16–69 years old who identified as gay * proportion who had at least one male sex partner in the 12 months before the survey	Australian Bureau of Statistics, ASHR 2	Not reported	127,947 of sexually active 16–69 year-old gay men	National representative survey	Australian men aged 16–69 years old who identified as gay and had at least one male sex partner in the 12 months before the survey

Abbreviations:

^aMSM-Men who have sex with men

^bCHM-Canada Health Monitor

^cNSFG-National Survey of Family Growth

^dNHANES-National Health and Nutrition Examination Survey

^eNHBS-National HIV Behavioral Surveillance

^fHIV-Human immunodeficiency virus

^gASHR-Australian Study of Health and Relationships

^hKABaSTI-Knowledge, Attitudes and Behaviour as to Sexually Transmitted Infections

ⁱGMA-Gay Men and AIDS survey

^jCCHS-Canadian Community Health Survey

^kNATSAL-National Survey of Sexual Attitudes and Lifestyles

^l>YRBS-Youth Risk Behavior Survey

^mLBG-Lesbian, gay, or bisexual

ⁿONS-Office of National Statistics