1. Anal Sex Among Young Heterosexuals in Three US STD Clinics Pamina M. Gorbach 1, Lisa E. Manhart 2, Bradley P. Stoner 3, David H. Martin 4 1 University of California Los Angeles, 2 University of Washington, 3 Washington University St. Louis, 4 Louisiana State University

2. Introduction There is a growing body of literature on the practice of anal intercourse (AI) among heterosexuals Research on AI among heterosexuals has clarified its practice in Western Countries, Brazil, India, and South Africa; most detailed data available from US Elevated risk for HIV transmission

3. Study Objectives Measure the prevalence of lifetime and recent practice of AI among young adults in STD clinics Describe individual & partnership factors affecting AI practice among these high risk young adults Examine the associations between AI and other behavior risky for HIV acquisition

4. Methods: Young Adults, Partnerships, and STD (YAPS) 1,220 young adults aged 18-26 attending public STD clinics in Seattle, New Orleans, and St Louis were interviewed and tested for STDs between 2001-04 Behavioral data collected by self-administered computer interview (CASI) Heterosexuals were those who self-identified as “100% heterosexual” (n=920; 76%). Study was a project of UW STD CRC (NIH/NIAID AI31448)

5. Total (n=920) % (n) Ever AI (n=301) % (n) Gender: Male Female 63.4(583)* 36.5 (336) 32.6 (190) 33.0 (111) Race/Ethnicity: White Black Other 22.5 (202) 69.5 (637) 8.4 (77) 37.8 (76) 30.7 (194) 36.9 (28) Lifetime Number of Partners**17.2 (8)24.7 (12)* Number of Partners In Past Year**3.9 (3)4.6 (3)* Ever sex for $ or Goods**12.0(110)*21.6(65) Sex W/ Partner Same Day Met**52.6 (483)68.1(205) Ever IDU2.3 (21)42.9 (9) Current partner reported43.6% (401)33.9 (136) Characteristics & Behaviors Among Young Adults from 3 STD Clinics Reporting Anal Sex (n=920) UW STD CRC (NIH/NIAID AI31448) *Among sexually active =94%

6. Percent Reporting Ever Anal Sex: (n=301/919) UW STD CRC (NIH/NIAID AI31448) 33% (n=301) reported ever practicing AI (32% of females and 33% of males)

7. % Reporting: AI with Any of Last 3 & Last Partner n=81/338 n=127/588

8. Factors Associated w/ Ever AI: Unadjusted ORs UW STD CRC (NIH/NIAID AI31448) Unadjusted Ever Anal Sex Odds Ratio[95% Conf. Interval] Male0.990.74 - 1.30 African American* 0.73 0.52 - 1.01 Other Race* 0.96 0.56 - 1.66 Lifetime # sex partners 1.01 1.00- 1.02 Sex on same day met partner2.62 1.96 - 3.50 Ever received money for sex 3.592.38 - 5.41 Ever IDU1.550.65 – 3.72 *White = reference group

9. Multivariate Analysis of Ever AI: Adjusted ORs (n=823)

10. Last Partnership: Characteristics Age discordant > 5 years: 18% –28.5% of females, 11.7% of males Partnership Type (n=401) –exclusive 59.6% (n=239) –dating-not exclusive 17.7% (n= 71) –dating- infrequently 10.5% (n= 42) –Only sex 12.2% (n=49)

11. Last Partnership: Dynamics Sexual Initiate: –Among females: 40% equal; 13% she initiates; 28% he initiates –Among males: 55% equal; 33% he initiates; 12% she initiates 29% reported physical abuse (148/499) 14.5% reported being forced to have sex* (72/497) *”insisted or made to have sex when you/he/she didn’t want to”

12. Factors Associated w/ AI w/ Last Partner: Unadjusted ORs AI Last Partner Unadjusted OR[95% CIl] Male0.700.48 - 1.00 African American* 0.64 0.42 - 0.97 Other Race* 0.80 0.39 - 1.62 Lifetime # sex partners 1.00 0.99 - 1.01 Sex on same day met partner1.52 1.04 - 2.22 Ever received money for sex 2.321.44 - 3.73 Age Discordant1.591.02 – 2.49 Forced sex with partner2.231.28 – 3.88 Physical abuse with partner1.901.21 – 3.03 Partner – dating not exclusive0.790.38 – 1.67 Partner – dating infrequent0.970.40 – 2.33 Partner – only sex1.400.66 - 2.96

13. Multivariate Analysis of AI with Last Partner: Adjusted ORs (n=461) Reference Groups: Sex = Male; Ethnicity= White

14. Last Partner: Other AI AI >1 time w/ last partner: 47% Only 39% reported EVER condom use during AI w/ last partner –32% of females –45% of males UW STD CRC (NIH/NIAID AI31448)

15. AI - By “Virgins”? 14% of those who reported never having vaginal sex reported having AI 12 women reported never vaginal sex; –25% (3) had ever AI; –25% (3) reported AI with 1 of past 3 partners 43 hetero men reported never vaginal sex –12% (5) reported ever AI –16% (7) reported AI with at least 1 of last 3 partners. UW STD CRC (NIH/NIAID AI31448)

16. Characteristics Associated w/ Anal Sex Age Discordant Own Behavior/ Characteristics Partnership Characteristics Physical Abuse Forced sex Female Ethnicity - white? Injection Drug use Sell/trade sex Sex on day met

17. Conclusions: AI Many young hetero’s in STD clinics report AI (1/3) suggesting high lifetime rates and early initiation Confluence of risks : those practicing AI also report other risky behaviors –Selling/trading sex –Injecting drugs –Sex without knowing partner long –Physical & sexually abusive partnerships Some young adults, especially females, may use to maintain “virginity” but be unaware of HIV risk of AI

18. Implications AI Among Young STD Patients Compounded risks for HIV acquisition with AI such as low condom use, abusive partnerships, commercial sex practice, & drug injection suggest the need for broad behavioral counseling for young adults in STD clinics Co-occurrence with sexual abuse and violence in partnerships needs further research but is a special cause for concern