Table 4.

Studies using census-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 men aged 45 and over never married * census population of adult men 15 and over	Census data	Not reported	Toronto=35,000, Montreal=37,000, Vancouver=26,500	Proportion of never married men obtained from census	Men aged 45 and over that have never been married
de Voux et al., 2017 (29)	United States/44 states	Percent MSMa =percent of male head-male unmarried partner households in county * number of men in county; scaled to equal 3.9% of adult male population	ACSb summary data; rural-urban classification from NCHSc; Purcell et al., 2012 for 3.9%	3.8% of all men overall	3,921,515 overall	American Community Survey summary data	Households with a male head and a male partner
Lieb et al., 2009 (30)	United States/17 southern states	Model A: % MSM statei= (rural male population statei * 0.01) + (suburban male population statei * 0.04) + (urban male population statei * 0.09) Model B: 1.MSM index= statei (#SSMPe statei/#SSMP US /( #households statei/#households US) 2. Percent MSM statei= (MSM index statei * % MSM Model A statei). 3. Average %MSMstatei= (%MSM model A statei + %MSM modelBstatei)/2. 4. Number of MSMstatei= average%MSMstatei * adult male population statei. Model C: RaceiMSMestimate= average % MSM statei x racei adult male population statei * % MSM ratio for racei. Model C final estimate =White MSM estimate + Black MSM estimate + Hispanic MSM estimate + Other race MSM estimate	2000 Census, NSFGd, ACS	6.0% in the south	2.4 million in the south 1,656,500 (69%) whites, 339,400 (14%) blacks, 368,800 (15%) Hispanics, 34,600 (1.4%) Asian/Pacific Islanders, 7,700 (0.3%) American Indians/Alaska Natives, and 11,000 (0.5%) others	US Census Bureau; multi-stage area probability sample (NSFG)	Adult males who ever had sex with another male
Lieb et al., 2011 (31)	United States	Model A: % MSM statei= (rural male population statei * 0.01) + (suburban male population statei * 0.04) + (urban male population statei * 0.09) Model B: 1.MSM index= statei(#SSMP statei/#SSMP US /( #households statei/#households US) 2. Percent MSM statei= (MSM index statei x % MSM Model A statei). 3. Average %MSMstatei= (%MSM model A statei + %MSMmodelBstatei)/2. 4. Number of MSMstatei= average%MSMstatei * adult male population statei. Model C: RaceiMSMestimate= average % MSM statei * racei adult male population statei * % MSM ratio for racei. Model C final estimate =White MSM estimate + Black MSM estimate + Hispanic MSM estimate + Other race MSM estimate	2000 Census, NSFG, ACS	Overall US percentage of males who were MSM was 6.4%, varied from 3.3% in South Dakota to 13.2% in the District of Columbia	7.1 million MSM residing in the US in 2007; ranged from 9,612 in Wyoming to 1,104,805 in California 71.4% (5.1 million) were white, 15.9% (1.1 million) were Hispanic, 8.9% (635,000) were black, 2.7% (191,000) were Asian, 0.4% (26,000) were American Indian/Alaska Native, 0.1% (6,000) were Native Hawaiian/other Pacific Islander, and 0.6% (41,000) were of multiple/unknown race/ethnicity	US Census Bureau; multi-stage area probability sample (NSFG)	Adult males aged ≥18 years with a lifetime history of any male-male sexual contact
Campagna et al., 2015 (32)	United States/Texas/counties	Model A: % MSM countyi=(rural male population countyi *0.01) + (suburban male population countyi *0.04) + (urban male population countyi * 0.09) Model B: 1.MSM index= countyi(#SSMP countyi/#SSMP Texas /( #households countyi/#households Texas) 2. Percent MSM countyi= (MSM index countyi * % MSM Model A countyi). 3. Average %MSMcountyi= (%MSM model A county + %MSM modelBcountyi)/2. 4. Number of MSMcountyi= average%MSMcountyi * adult male population countyi. Model C: RaceiMSMestimate= average % MSM countyi * racei adult male population countyi * Lieb’s % MSM ratio for racei. Model C final estimate =White MSM estimate + Black MSM estimate + Hispanic MSM estimate +Other race MSM estimate	United States Census (2000 and 2010), ACS (2010)	6.4% of adult male population in Texas; 10.3% in Dallas; 9.8% in Austin; 1.0 to 12.9% at county level	599,683 in Texas in 2012 315,000 (53 %) Whites; 56,000 (9 %) Blacks; 213,000 (36 %) Hispanic/Latinos; 16,000 (3 %) men of other races	US Census Bureau	Households with same-sex male unmarried partners
Grey et al., 2016 (4)	United States/states/counties	1.MSM index countyi urbanicityj= (#SSMf households countyi urbanicityj/total households countyi urbanicityj/( SSM households urbanicityj /total households urbanicityj) 2. Percent MSM countyi urbanicity j= (MSM index countyi urbanicityj * % MSM urbanicityj) 3. MSMcountyi urbanicity j= (%MSM countyi urbanicityj * Adult males countyi urbanicityj. 4. (impute) SSM households countyi urbanicityj= SSM households countyi urbanicityj+(total households countyi urbanicityj * %SSM households urbanicityj)	2009–2013 ACS	3.9%	4,503,080 MSM in the US	ACS 5-year summary file, 2009 to 2013, US households are randomly sampled each year	Number of same-sex male households

Abbreviations:

^aMSM-Men who have sex with men

^bACS-American Community Survey

^cNCHS-National Center for Health Statistics

^dNSFG-National Survey of Family Growth

^eSSMP-Same sex male partner

^fSSM-Same sex male