Table 1:

Measures used for bivariate and multivariable analyses (Standardized Cronbach’s alpha is given for each ordinal composite variable measured on the five-point Likert scale)

PARTNER SUPPORT FOR CONDOM USE	Scored as: average of the following responses to the 7 items listed
	0 Strongly Disagree	1 Disagree	2 Neither Agree nor Disagree	3 Agree	4 Strongly Agree
Cronbach’s alpha = 0.88	Most recent sex partner would be mad at me if I asked to use condoms. (reverse coded) Most recent sex partner would be proud of me if I asked to use condoms. Most recent sex partner would break up with me if I asked to use condoms. (reverse coded) Most recent partner would be supportive if I asked to use condoms. Most recent partner would think I have other partners if I asked to use condoms. (reverse coded) Most recent partner would appreciate it if I asked to use condoms. Most recent partner would be jealous if I asked to use condoms. (reverse coded)
PERCEIVED STI/HIV RISK	Scored as: average of the following responses to the 5 items listed
	0 Strongly Disagree	1 Disagree	2 Neither Agree nor Disagree	3 Agree	4 Strongly Agree
Cronbach’s alpha = 0.79	If I don’t use condoms, I could get infected with an STD or HIV in the next 3 months. Unless I change my behavior, I am likely to get an STD or HIV. If I don’t reduce the number of people I have unprotected sex with, I could get infected with a STD or HIV. If I keep having unprotected sex with my partner(s), I could get infected with a STD or HIV. Sometimes I think that it’s only a matter of time before I get a STD or HIV.
CONDOM USE SELF-EFFICACY IN PARTNERSHIP	Scored as: average of the following responses to the 5 items listed
	0 Strongly Disagree	1 Disagree	2 Neither Agree nor Disagree	3 Agree	4 Strongly Agree
Cronbach’s alpha = 0.92	Can use a condom even if most recent sex partner does not want to. Can use a condom every time you have sex with most recent sex partner. Can use a condom even if you want to feel close with most recent sex partner. Can use condom even if you are making up with most recent sex partner after a fight. Can use condom even high or drunk with most recent sex partner.
CONDOM USE BELIEFS	Scored as: average of the following responses to the 4 items listed
	0 Strongly Disagree	1 Disagree	2 Neither Agree nor Disagree	3 Agree	4 Strongly Agree
Cronbach’s alpha = 0.85	Condoms ruin the mood. Sex doesn’t feel as good when you use a condom. Sex with condoms doesn’t feel natural. Using condoms breaks up the rhythm of sex.
ABILITY TO STOP SEX WITHOUT CONDOMS	Scored as: average of the following responses to the 6 items listed
	0 Strongly Disagree	1 Disagree	2 Neither Agree nor Disagree	3 Agree	4 Strongly Agree
Cronbach’s alpha = 0.89	I could stop having sex to get a condom even if I’m really turned on. I could cool off and stop having sex if no condom was available. I could stop having sex to get a condom even if it meant getting dressed and going to the store. I could stop having sex to get a condom even with a really hot new partner. I could stop having sex to get a condom even with someone I want to have a relationship with. I could stop having sex to get a condom even with someone I am in love with.
CONDOM USE INTENTIONS	Scored as: average of the following responses to the 7 items listed
	0=I am already (using condoms every time I have vaginal sex or anal sex with a MAIN partner, etc. from each question) and plan to continue    1=I want to … every time 2=I’m not sure I want to … every time   3=I do not want to … every time   4=I do not plan to have any sex partners in the next 3 months
	Do you intend to use condoms every time you have vaginal or anal sex with a MAIN partner? Do you intend to use condoms every time you have vaginal or anal sex with partners OTHER THAN a main partner? Do you intend to use condoms until your partner has been tested for HIV, and is HIV negative? Are you sure that you can use condoms until your partner has had a check-up for STDs, and doesn’t have any? Do you intend to use condoms more often than in the past 3 months? Do you intend to keep condoms nearby so they will be close when you need them? Do you intend to discuss using condoms with partners?
CONDOM USE KNOWLEDGE	Scored on following scale: 0=no, 1=yes
	Space should be left at the tip of a condom. Time to put on a condom is right before a man comes or ejaculates. (reverse coded) When a man uses a condom, he should unroll it first and then slip it on. When women have anal sex with men, they don’t need to use condoms. (reverse coded)
STI KNOWLEDGE	Scored on following scale: 0=no, 1=yes
	Some STDs can make women sterile (not able to have a baby). You can’t tell if a man or woman has a STD by looking at him or her. A woman who has an STD will usually have symptoms. (reverse coded) A man who has an STD will usually have symptoms. (reverse coded) It doesn’t matter what kind of lubricant you use with your condom. (reverse coded)
COMFORT IN OBTAINING CONDOMS	Scored on following scale: 0=no, 1=yes
	I can get condoms whenever I want without difficulty. I wouldn’t mind buying condoms. I would feel uncomfortable carrying condoms with me. (reverse coded) I can get condoms out of a condom machine in a club or bar.
INTENTIONS FOR SAFER-SEX BEHAVIORS	Scored as: average of the following responses to the 2 items listed
	0=I want to   1=I’m not sure I want to   2=I do not want to   3=I do not plan to have sex in the next 3 months
	Do you intend to have fewer sex partners in the next 3 months, than you had in the past 3 months? Do you intend to get to know new partners better before you have sex with them?
	Scored as: average of the following responses to the 3 items listed
	0=I have (avoided having sex while drinking or using drugs, etc.) and I plan to continue   1=I want to…   2=I’m not sure I want to…   3=I do not want to…   4=I do not plan to … in the next 3 months
	Do you intend to avoid having sex when drinking or using drugs too much? Do you intend to break-up with a partner who puts you at risk of getting STDs? Do you intend to go without having sex with your partner until you have been treated and cleared?
CONSISTENT CONDOM USE	For each partner, respondents were asked:
	“In the past 3 months, how many times in total did you have anal sex with (partner’s name)?” “During the (# times) that you had anal sex with (partner’s name), how many times did you use a condom?”
	$$\frac{\mathrm{Total\; number\; of\; anal\; sex\; acts\; with\; a\; condom}}{\mathrm{Total\; number\; of\; anal\; sex\; acts}}=\%\mathrm{Condom\; use}$$
	Consistent condom use was defined as 100% condom use. Inconsistent/nonuse condom use was defined as less than 0-99% condom use.