Author (publication year)	Outcome	Population definition	Sample size (n)	Proportion, mean (SD), median (range)
Arrington-Sanders et al. (2014)	Median partners in past 6 months	Not explicit	31	3 (0–32)
Everett et al. (2014)	More than one sex partner in past 90 days	Identify as gay or bisexual, or had sexual contact with males in their lifetime; sexually active (at least 1 partner)	855	0.212
Goodenow et al. (2002)	Ever been diagnosed with any sexually transmitted disease	Sexual act with male partner	79	0.19
Halkitis et al. (2011)	Mean age of insertive anal sexual debut	Sexual act with male partner	39	15.2 (no SD)
	Mean age of receptive anal sexual debut	Sexual act with male partner	39	14.7 (no SD)
Halkitis et al. (2013)	Any unprotected insertive anal sex in past 30 days	Report having had sex with another man in the 6-month period before screening	592	0.11
	Any unprotected receptive anal sex in past 30 days	Report having had sex with another man in the 6-month period before screening	592	0.14
	Any unprotected receptive AND insertive anal sex in past 30 days	Report having had sex with another man in the 6-month period before screening	592	0.05
	Mean age of insertive anal sexual debut	Report having had sex with another man in the 6-month period before screening	592	16.3 (1.7)
	Mean age of receptive anal sexual debut	Report having had sex with another man in the 6-month period before screening	592	16.2 (1.8)
Kann et al. (2016)	Had sexual intercourse with four or more persons during their life	Sexual contact with male in lifetime	1681	0.35
Mustanski, Andrews et al. (2014a)	Risky sex (defined as no condom use at last sexual event and 2 + sexual partners in past 3 months)	Sex with male in lifetime	1185	0.16
	Intimate partner violence in past 12 months	Sex with male in lifetime	1185	0.25
Rotheram-Borus, Reid et al. (1994)	Consistent condom use during anal sex (condoms used during all anal sex acts) in past 3 months	Self-identified as gay or bisexual and had anal sex in past 3 months	71	0.45
	Proportion of anal sex acts that were protected in past 3 months	Self-identified as gay or bisexual and had anal sex in past 3 months	71	0.59
	Mean # of male sex partners (anal or oral) in past 3 months	Self-identified as gay or bisexual	135	2.4 (no SD)
	Mean # of anal or oral sex acts in past 3 months	Self-identified as gay or bisexual	72	3.5 (5.5)
	Mean # of unprotected anal sex acts in past 3 months	Self-identified as gay or bisexual	68	3.5 (no SD)
Rotheram-Borus, Rosario et al. (1994)	Any condom use by partner in lifetime	Self-identified as non-heterosexual, and who engaged in sexual activity where condom could be used by partner	115	0.84
	Any condom use by partner in past 3 months	Self-identified as non-heterosexual, and who engaged in sexual activity where condom could be used by partner	86	0.64
	Any condom use by self in lifetime	Self-identified as non-heterosexual, and who engaged in sexual activity where condom could be used by self	110	0.87
	Any condom use by self in past 3 months	Self-identified as non-heterosexual, and who engaged in sexual activity where condom could be used by self	80	0.51
	Any insertive anal sex in lifetime	Self-identified as non-heterosexual	131	0.66
	Any insertive anal sex in past 3 months	Self-identified as non-heterosexual	131	0.34
	Any receptive anal sex in lifetime	Self-identified as non-heterosexual	131	0.73
	Any receptive anal sex in past 3 months	Self-identified as non-heterosexual	131	0.44
	Reported only one male partner in past 3 months	Self-identified as non-heterosexual and had sex in past 3 months	91	0.37
	Reported 5 or more male partners in past 3 months	Self-identified as non-heterosexual and had sex in past 3 months	91	0.27
	Reported 4 + male receptive anal sex partners in past 3 months	Self-identified as non-heterosexual and had receptive anal sex in past 3 months	57	0.19
	Reported 4 + male insertive anal sex partners in past 3 months	Self-identified as non-heterosexual and had insertive anal sex in past 3 months	91	0.09
	Median lifetime male partners	Self-identified as non-heterosexual; sexually active	117	7 (1–3000)
	Mean lifetime male partners	Self-identified as non-heterosexual; sexually active	117	70.1 (340.9)
	Median male partners past 3 months	Self-identified as non-heterosexual; sexually active with males	91	2 (1–631)
	Mean male partners past 3 months	Self-identified as non-heterosexual; sexually active with males	91	10.3 (65.9)
	Median sexual encounters with males in lifetime	Self-identified as non-heterosexual; sexually active with males	114	39 (1–3120)
	Median sexual encounters with males in past 3 months	Self-identified as non-heterosexual; sexually active with males in past 3 months	91	8 (no range reported)
Rotheram-Borus, Rosario et al. (1995)	Mean # of male sex acts/encounters in past 3 months	Self identified as homosexual or bisexual	136	7.2 (10)
	Mean # of male sex partners in past 3 months	Self identified as homosexual or bisexual	136	1.9 (2.3)
	Mean # of unprotected anal sex acts in past 3 months	Self identified as homosexual or bisexual	136	1.4 (3.3)
	Mean # of male unprotected sex acts in past 3 months	Self identified as homosexual or bisexual	136	7.6 (11.8)
	Mean # of unprotected oral sex acts in past 3 months	Self identified as homosexual or bisexual	136	5.6 (8.3)
Saewyc, Skay et al. (1998)	History of sexual abuse	Self-report as gay, bisexual or unsure	320	0.08
	Weekly intercourse	Self-report as gay, bisexual or unsure	320	0.12
Waldo et al. (2000)	Any unprotected insertive anal sex in past 6 months	Self-identified as gay or bisexual	100	0.20
	Any unprotected receptive anal sex in past 6 months	Self-identified as gay or bisexual	100	0.22
	Ever had a STI	Self-identified as gay or bisexual	100	0.05
	Known HIV-positive sex partner in past 6 months	Self-identified as gay or bisexual	100	0.02
	Mean # of male sex partners in past 6 months	Self-identified as gay or bisexual	100	2.4 (4.2)