Supplemental Table 1. Survey questionnaire (created by the authors) Sexual Communication Self-Efficacy (Quinn-Nilas et al., 2016)
“How difficult would it be to do the following with your current or future sexual partner(s)?”
1. Ask how many sexual partners they have had?
Very difficult Difficult Easy Very easy 2. Ask if they have ever shared needles? Very difficult
Difficult Easy Very easy 3. Ask if they are currently having sex with
other people?
Very difficult Difficult Easy Very easy 4. Ask if they have or ever had any sexually
transmitted infections (STIs)?
Very difficult Difficult Easy Very easy 5. Ask if a condom could be used for sex with
them?
Very difficult Difficult Easy Very easy 6. Demand for a condom to be used during
sex?
Very difficult Difficult Easy Very easy 7. Refuse to have sex if they won’t use a
condom?
Very difficult Difficult Easy Very easy 8. Tell them a certain sexual activity hurts
you?
Very difficult Difficult Easy Very easy 9. Tell them if a certain sexual activity is not
making you feel good?
Very difficult Difficult Easy Very easy 10. Suggest a new sexual activity (e.g. a new
sexual position)?
Very difficult Difficult Easy Very easy 11. Tell them you do not want to have sex? Very difficult
Difficult Easy Very easy 12. Tell them you would like to have sex more
often?
Very difficult Difficult Easy Very easy
13. Tell them that a sexual activity feels good? Very difficult Difficult Easy Very easy 14. Talk about how it feels to use a condom? Very difficult
Difficult Easy Very easy 15. Talk about how to put on a condom? Very difficult
Difficult Easy Very easy 16. Talk about whether a condom is worn
correctly?
Very difficult Difficult Easy Very easy 17. Tell them that you want to have sex? Very difficult
Difficult Easy Very easy 18. Tell them that you like a specific sexual
activity?
Very difficult Difficult Easy Very easy
19. Initiate sex? Very difficult
Difficult Easy Very easy Gender Equitable Men Scale:
“Inequitable” Gender Norms (Pulerwitz & Barker, 2008)
“To what extent do you agree or disagree with the following statements?”
20. It is the man who decide what type of sex to have.
Agree Partially agree Do not agree 21. A woman’s most important role is to take
care of her home and cook for her family.
Agree Partially agree Do not agree 22. Men need sex more than women do. Agree
Partially agree Do not agree 23. Women who carry condoms on them are
“easy”. Agree
Partially agree Do not agree 24. Women should remain as virgins until they
get married.
Agree Partially agree Do not agree 25. A man should have the final word about
decisions in his home.
Agree Partially agree Do not agree 26. Men are always ready to have sex. Agree
Partially agree Do not agree 27. There are times when a woman deserves to
be beaten.
Agree Partially agree Do not agree
28. A woman should tolerate violence in order to keep her family together.
Agree Partially agree Do not agree 29. Real men only have sex with women. Agree
Partially agree Do not agree 30. It disgusts me when I see a man acting like
a woman and vice versa.
Agree Partially agree Do not agree 31. I would never have a gay friend. Agree
Partially agree Do not agree Gender Equitable Men Scale:
“Equitable” Gender Norms (Pulerwitz & Barker, 2008)
“To what extent do you agree or disagree with the following statements?”
32. A couple should decide together if they want to have children.
Agree Partially agree Do not agree 33. In my opinion, a woman can suggest
condom use just like a man can.
Agree Partially agree Do not agree 34. A man should know what his partner like
during sex.
Agree Partially agree Do not agree 35. Both parties should decide together what
type of contraceptive to use.
Agree Partially agree Do not agree 36. If she wants, a woman can have more than
one sexual partner.
Agree Partially agree Do not agree Sexual Relationship Power Scale:
Relationship Control (Pulerwitz et al., 2000)
“How closely the followings describe your previous or current partner(s)?”
37. My partner(s) would get angry if I suggested condom use.
Strong agree Agree Disagree Strongly disagree 38. My partner(s) would get violent if I
suggested condom use.
Strong agree Agree Disagree Strongly disagree 39. Most of the time, we do what my partner(s)
wants/want to do.
Strong agree Agree Disagree Strongly disagree 40. My partner(s) does what they want, even if I
do not want them to.
Strong agree Agree Disagree Strongly disagree 41. My partner(s) has/have more say than I do
about important decisions that affect us.
Strong agree Agree Disagree Strongly disagree
42. My partner(s) always wants to know where I am.
Strong agree Agree Disagree Strongly disagree 43. My partner(s) decide who I can and cannot
spend time with.
Strong agree Agree Disagree Strongly disagree 44. I am more committed to our relationship
than my partner(s) is/are.
Strong agree Agree Disagree Strongly disagree 45. I feel trapped or stuck in our relationship. Strong agree
Agree Disagree Strongly disagree Sexual Relationship Power Scale:
Decision-Making Dominance (Pulerwitz et al., 2000)
“Who usually make the following decisions in the relationships?”
46. Who usually has more say about whose friends to go out with?
Your partner(s) Shared decision You
47. Who usually has more say about how often you see one another?
Your partner(s) Shared decision You
48. Who usually has more say about what you do together?
Your partner(s) Shared decision You
49. Who usually has more say about when you talk about serious issues?
Your partner(s) Shared decision You
50. Who usually has more say about whether you have sex?
Your partner(s) Shared decision You
51. Who usually has more say about what types of sexual acts you do?
Your partner(s) Shared decision You
52. Who usually has more say about whether you use condoms?
Your partner(s) Shared decision You
53. In general, who do you think has more power in the relationship?
Your partner(s) Shared decision You
Sexual Self-Efficacy Scale (Rosenthal et al., 1991)
“How certain do you think you are that could do any of the following activities?”
54. Refuse a sexual advance by your partner. Completely certain Very certain Somewhat certain Not very certain Not certain at all 55. Have a sexual encounter without feeling
obliged to have intercourse.
Completely certain Very certain Somewhat certain Not very certain Not certain at all
56. Put a condom on an erect penis. Completely certain Very certain Somewhat certain Not very certain Not certain at all 57. Initiate sexual activities. Completely certain
Very certain Somewhat certain Not very certain Not certain at all 58. Discuss using condoms and/or other
contraceptives with a potential partner.
Completely certain Very certain Somewhat certain Not very certain Not certain at all 59. Ask a potential partner to wait if
precautions are not available at the time.
Completely certain Very certain Somewhat certain Not very certain Not certain at all 60. Carry condoms around with you ‘just in
case’. Completely certain
Very certain Somewhat certain Not very certain Not certain at all 61. Control your sexual urges while under the
influence of alcohol or drugs.
Completely certain Very certain Somewhat certain Not very certain Not certain at all 62. Meet your own sexual needs by
masturbation.
Completely certain Very certain Somewhat certain Not very certain Not certain at all 63. Discuss with a partner the use of condoms
for HIV/STI protection when other means of contraception are already being used.
Completely certain Very certain Somewhat certain Not very certain Not certain at all 64. Choose when and with whom to have sex. Completely certain
Very certain Somewhat certain Not very certain Not certain at all 65. Tell your partner how to treat you sexually. Completely certain
Very certain Somewhat certain Not very certain Not certain at all 66. Refuse to do something sexually which you
don’t feel comfortable about. Completely certain Very certain Somewhat certain Not very certain Not certain at all
67. Be able to buy condoms/contraceptives. Completely certain Very certain Somewhat certain Not very certain Not certain at all 68. Discuss precautions with a doctor or health
professional.
Completely certain Very certain Somewhat certain Not very certain Not certain at all 69. Admit being inexperienced to your sexually
experienced peers.
Completely certain Very certain Somewhat certain Not very certain Not certain at all 70. Reject an unwanted sexual advance from
someone other than your partner. e.g. an acquaintance
Completely certain Very certain Somewhat certain Not very certain Not certain at all 71. Watch sexually explicit movies without
embarrassment.
Completely certain Very certain Somewhat certain Not very certain Not certain at all 72. Ask someone other than your partner for a
date.
Completely certain Very certain Somewhat certain Not very certain Not certain at all 73. Ask your partner to provide the sexual
stimulation you require.
Completely certain Very certain Somewhat certain Not very certain Not certain at all HIV and other STI Knowledge
74. HIV Pre-Exposure Prophylaxis is an effective means of preventing HIV infection
True False Don’t Know 75. HIV Pre-Exposure Prophylaxis can also
reduce the chances of acquiring other STIs
True False
Don’t Know 76. Gonorrhea can be transmitted through oral
sex
True False
Don’t Know 77. The human papilloma virus (HPV) cannot
be transmitted through oral sex
True False Don’t Know
78. There is a/are clinics in Singapore where I can test anonymously for HIV and Syphilis
True False
Don’t Know 79. An HIV-positive individual who has
achieved viral suppression or an 'undetectable' viral load has almost zero chances of transmitting the virus to someone else through sexual intercourse
True False Don’t Know
80. An HIV-positive individual on effective treatment can live a long, healthy, and productive life
True False
Don’t Know HIV Pre-Exposure Prophylaxis and Post-Exposure Prophylaxis 81. Have you heard of HIV Pre-Exposure
Prophylaxis (PrEP)?
Yes, I am currently on PrEP
Yes, I have taken it but no longer do so Yes, I have heard of it but not taken it No, I have never heard of it
82. Have you heard of HIV Post-Exposure Prophylaxis (PEP)?
Yes, I have taken it before
Yes, I have heard of it but not taken it No, I have never heard of it
HIV and Other STIs Risk Perception, Testing Intentions and Behaviors 83. How much risk do you think you are at of
getting HIV?
Slider scale: 0 to 10 (0=no risk at all; 10=very high risk) 84. How much risk do you think you are at of
getting other STIs?
Slider scale: 0 to 10 (0=no risk at all; 10=very high risk) 85. How likely are you to go get a test for HIV
in the next three months?
Extremely unlikely to get tested Very unlikely to get tested Somewhat unlikely to get tested Somewhat likely to get tested Very likely to get tested Extremely likely to get tested 86. How likely are you to go get a test for other
STI in the next three months?
Extremely unlikely to get tested Very unlikely to get tested Somewhat unlikely to get tested Somewhat likely to get tested Very likely to get tested Extremely likely to get tested
