Table 2.

Studies using surveillance-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	Number of MSMa tested for HIVb in 1996 from provincial serodiagnostic databases/proportion of MSM that reported being tested for HIV during a 1 year period from surveys and studies	Provincial serodiagnostic databases and epi studies	Not reported	Toronto=39,100, Vancouver=15,900	All individuals who come forward for HIV testing	Sex with other men, self-identification as gay, or sexual relations with other men
Lieb et al., 2004 (12)	United States/Florida/Miami MSAc	HIV prevalence among MSM in Miami (extrapolated from national estimate)/estimated HIV seroprevalence rates among MSM from Urban Men’s Health Study	Florida Department of Health	9.5%	76,500	Persons diagnosed and reported to the Florida Department of Health HIV/AIDS Reporting System	Male resident aged 18 years or older who had any male–male sex contact after 1977
Lieb et al., 2007 (13)	United States/Florida/Miami-Dade County MSA	HIV prevalence in Miami MSA/HIV seropositivity rates from NHBSd	Florida Department of Health, NHBS	7.5%	63,020 in Miami MSA for 2003 to 2005	HIV-infected MSM living and residing in the Miami MSA	All men aged ≥18 years who had male-male sex contact since 1978
Livak et al., 2013 (14)	United States/Illinois/Chicago	Average HIV Seroprevalence Rate for YBMSMe (adjusted for HIV positive but unaware)/Population-Based Seroprevalence Rate among YBMSM (averaged from NHBS and SRNf);	Chicago Department of Public Health, 2010 US Census, NHBS, and SRN.	11.7%	6,340	YBMSM living with HIV infection in Chicago	Men who have had male–male sexual contact
Marcus et al., 2013 (15)	Europe	Npop = HIVpop*Nsvy*SSD/HIVsvy HIVpop, the number of HIV cases diagnosed among MSM reported to the countries surveillance system in 2009; Nsvy, the sample size in a national survey; HIVsvy, the number of those survey participants diagnosed with HIV in 2009; Ntot, the number of men in the country; M, the proportion who have sex with men SSD=HIVsvy*M*Ntot/Nsvy*HIVpop	EMISg, National surveillance data from ECDCh, Eurostat, and from national statistics	Relative MSM population sizes were between 0.03% and 5.6% of the adult male population aged 15–64	Not reported	National surveillance data on newly diagnosed HIV infections among MSM	Having had at least one sexual contact with a man within the previous 12–24 months
Raymond et al., 2013 (16)	United States/California/San Francisco	(HIV/AIDSi Cases * undiagnosed infection)/HIV prevalence	Case surveillance data, HIV prevalence estimates, United States Census data, and undiagnosed HIV infection estimate	Not reported	59,809 MSM	Total number of known MSM and MSM-IDUj HIV/AIDS cases in registry	Not listed
Raymond et al., 2018 (34)	United States/California/San Francisco	HIV cases in registry * % undiagnosed HIV infection) / % HIV prevalence	HIV prevalence from NHBS survey in 2017 and proportion of MSM previously diagnosed with HIV from case registry in 2016	Not reported	63,242 MSM	HIV case registry for the city of San Francisco	Not listed

Abbreviations:

^aMSM-Men who have sex with men

^bHIV-Human immunodeficiency virus

^cMSA-Metropolitan statistical area

^dNHBS-National HIV Behavioral Surveillance

^eYBMSM-Young black men who have sex with men

^fSRN-Social Risk and Network Assessment

^gEMIS-European MSM Internet Survey

^hECDC-European Centre for Disease Prevention and Control

ⁱAIDS-Acquired Immune Deficiency Syndrome

^jIDU-Injection drug user