This study analyzed reasons for unprotected sex among men who have sex with men using an event-level analysis of data from 1046 men in the San Francisco Bay Area. The study found higher rates of unprotected insertive and receptive anal intercourse among HIV-negative men with HIV-positive partners. Negative moods and drug use during sex were more common in these serodiscordant partnerships. The study concludes event-level factors like mood, substance use, and beliefs about viral load need to be addressed in HIV prevention interventions.

1. Reasons for unprotected sex among
men who have sex with men:
An event-level analysis
Chongyi Wei, H. Fisher Raymond, Ron Stall, Willi McFarland
Presented at:
The 2011 National HIV Prevention Conference
Atlanta, GA
August 2011

2. Introduction
 Global associations between sexual risk taking and
patterns of personal behavior (e.g. substance use) have
been well documented
 However, such patterns of behavior may also be
challenged by context specific disinhibition
 Situational and event-level explanations for sexual risk
taking are less documented or understood
Objectives: We describe reasons for UAI at the event-level
among MSM’s seroconcordant and serodiscordant
partnerships

3. Methods
 Data: Baseline assessment (2008) of a longitudinal study
 Time-location sampling (TLS)
 Eligibility: Male, 18 or older, Bay Area resident, approached
by staff at the randomly selected VDT
 Self-administered on a handheld computer
 Measures:
 Individual socio-demographics
 A sexual activity matrix assessing sexual partner and
partnership characteristics including HIV status
 A series of event-level questions: Condom use during last sex
for each partner; mood at last sex; alcohol/drug use at last sex;
etc.
 Analysis:
Pearson’s Chi-square tests comparing partnerships of different
HIV status pairings

4. Results
 Samples
 N=1046
 Race/ethnicity: 52% White, 12% API, 7% Black, 20%
Latino, and 9% Other;
 Age: 16% 18-24; 36% 25-34, 25% 35-44, and 23% 45 or
older;
 Education: 55% college or above, 31% some college,
14 high school or less
 Sexual orientation: 90% gay, 8% bisexual, 2% straight
or other
 HIV status: 25% reported being HIV-positive

5. Results
 Partnerships that involved UAI by
participant’s and partner’s HIV status
 342 HIV-negative men reported 550 seroconcordant
partnerships (30.1%)
 46 HIV-negative men reported 66 serodiscordant
partnerships (35.5%)
 105 HIV-positive men reported 228 seroconcordant
partnerships (58.9%)
 46 HIV-positive men reported 63 serodiscordant
partnerships (32.6%)

6. Results
Neg-Neg Poz-Poz Neg-Poz Poz-Neg Χ2
Last sex
Top 57.1% 48.9% 75.8% 27.0% 35.6**
No condom 72.3% 84.8% 92.0% 56.3% 17.8**
Bottom 51.4% 66.2% 31.8% 73.0% 37.1**
No condom 76.5% 87.4% 85.7% 76.1% 8.8*
Top & bottom 16.9% 25.4% 10.6% 11.1% 13.3**
No condom 59.1% 82.8% 85.7% 57.1% 10.6*

7. Results
Neg-Neg Poz-Poz Neg-Poz Poz-Neg Χ2
Mood at last UAI
In a really good 67.1% 77.6% 53.0% 74.6% 17.7**
mood
Feeling 18.6% 6.6% 7.6% 4.8% 22.1**
infatuated or in
love
Want to escape 5.8% 7.0% 16.7% 3.2% 12.4**
daily life
Did not differ on: Feeling depressed/blue; feeling lust;
just not want to think about HIV for a while.

8. Results
Neg-Neg Poz-Poz Neg-Poz Poz-Neg Χ2
Drug use last UAI
You were on drug 18.0% 26.8% 42.4% 14.3% 26.6**
(s)
He was on drug 16.1% 25.9% 43.9% 17.5% 32.9%
(s)
Did not differ on: participant or partner was feeling the
effects of alcohol

9. Results
 Most endorsed reasons for last URAI
 Poz-poz: Weren’t concerned with re-infection
 Neg-poz: He had undetectable viral load; he pulled out
before cumming
 Poz-neg: I had undetectable viral load; I was the bottom
 Most endorsed reasons for last UIAI
 Poz-poz: Weren’t concerned with re-infection
 Neg-poz: I was the top
 Poz-neg: I had undetectable viral load

10. Conclusions
 Seropositioning appears prevalent for serodiscordant
pairs
 Viral load appears to affect sexual practices between
serodiscordant pairs
 Rates of UIAI, URAI or both were higher among neg-
poz pairs
 Negative moods and drug use during last sex were
more prevalent among neg-poz pairs

11. Conclusions
 Limitations
 TLS does not reach those who do not frequent MSM
venues
 Self-reported HIV status
 Partner assessment did not capture all partners in the
past 6 months, partnerships with riskier behavior
may have been missed

12. Conclusions
 Event-level factors associated with sexual risk
taking need to be taken into consideration when
planning HIV interventions as a specific focus on
contingency management
 Skill building around mood, managing daily life
and substance use, especially for HIV-negative
men who have serodiscordant partners even
when they have these partners infrequently