1. Anticipated Risk Compensation with Pre-Exposure Prophylaxis Use among North American Men who have Sex with Men Using an Internet Social Network D Krakower, M Mimiaga, J Rosenberger, D Novak, JA Mitty, J White, K Mayer.

2. PrEP can decrease HIV incidence among MSM, but risk compensation could reduce its potential benefit American men who have sex with men (MSM) at high-risk of HIV acquisition 1 1 Prejean 2011

3. PrEP can decrease HIV incidence among MSM, but risk compensation could reduce its potential benefit American men who have sex with men (MSM) at high-risk of HIV acquisition 1 iPrEx: oral antiretroviral pre-exposure prophylaxis (PrEP) can reduce the risk of HIV acquisition among MSM 2 1 Prejean 2011; 2 Grant 2010

4. PrEP can decrease HIV incidence among MSM, but risk compensation could reduce its potential benefit American men who have sex with men (MSM) at high-risk of HIV acquisition 1 iPrEx: oral antiretroviral pre-exposure prophylaxis (PrEP) can reduce the risk of HIV acquisition among MSM 2 If persons using PrEP decrease condom use with anal sex (i.e., risk compensation), net benefits of PrEP may be reduced 1 Prejean 2011; 2 Grant 2010

5. Our objective was to assess whether MSM anticipated decreased condom use with anal sex while using PrEP Cross-sectional survey  members of on-line partner-seeking network for MSM US + Canada 1 month after iPrEx (Dec 2010-Jan 2011)

6. Our objective was to assess whether MSM anticipated decreased condom use with anal sex while using PrEP Cross-sectional survey  members of on-line partner-seeking network for MSM US + Canada 1 month after iPrEx (Dec 2010-Jan 2011) Outcome questions: –“If I used the PrEP pill, I would decrease my condom use for insertive (top) anal sex.” –“If I used the PrEP pill, I would decrease my condom use for receptive (bottom) anal sex.”

7. 5035 HIV-uninfected MSM participated in the study Eligibility: –Biologic male –≥18 years of age –HIV-uninfected by self-report –Able to read English/use the Internet

8. We assessed factors associated with anticipated decreases in condom use while using PrEP Descriptive statistics

9. We assessed factors associated with anticipated decreases in condom use while using PrEP Descriptive statistics Bivariate  multivariable logistic regression analyses to assess correlates of anticipated decreases in condom use

10. We assessed factors associated with anticipated decreases in condom use while using PrEP Descriptive statistics Bivariate  multivariable logistic regression analyses to assess correlates of anticipated decreases in condom use –Demographics –Sexual Risk Behaviors, Self-perceived Risk of HIV Acquisition –Engagement in Healthcare –Awareness, Interest and Prior Use Regarding PrEP and Post-exposure Prophylaxis (PEP) –Psychosocial Characteristics, Substance use

11. Most participants were White and self-identified as homosexual/gay # Responding (Total N = 5035) AgeMean (SD)39 (12.8)5035 % Race/Ethnicity:Caucasian/White843252 Hispanic/Latino/Chicano63252 Multiracial/Other43252 African American/Black33252 Asian/Asian Amer./Pacific Isl.33252 Sexual Orientation: Homosexual/Gay843256 Bisexual163256 NationalityUS905035 Canada105035

12. Participants were highly-educated and moderately affluent; depression was common % # Responding (Total N = 5035) EducationAt least some college933255 EmploymentFull-time673254 Annual Income>$30,000683205 Health Insurance Covered873143 Healthcare Engagement Contact with provider past 12 months 903377 Identifies PCP823377 PsychosocialHistory of depression253277 Ever treated for drug/alcohol abuse 53217 PCP = primary care provider.

13. Many respondents reported high-risk behaviors, but average self-perception of risk was low-to-moderate % # Responding (Total N = 5035) High-Risk Sexual Behaviors 1 UAI ≥ 1 partner615035 UAI ≥ 1 partner HIV-infected or of unknown serostatus 235032 UAI after ≥ 5 drinks243222 UAI while using recreational drugs 113222 Prior sexually transmitted infection 285035 Self-perceived risk of HIV acquisition (1 = no risk, 10 = extreme risk): Mean (SD) 3.3 (2.3)3695 1 Prior 3 months. UAI = unprotected anal intercourse, male partner(s).

14. Awareness of PrEP was modest, and prior use was rare; half indicated interest in using daily oral PrEP % # Responding (Total N = 5035) ChemoprophylaxisHeard of PrEP193684 Prior PrEP use0.83683 Would use daily PrEP503542 Heard of PEP373695 Prior PEP use43693 Would use PEP883690

15. A substantial minority anticipated decreases in condom use while using PrEP % # Responding (Total N = 5035) Would decrease condom use during INSERTIVE anal sex while using PrEP 203245 Would decrease condom use during RECEPTIVE anal sex while using PrEP 143237

16. UAI and prior drug/alcohol abuse were assoc. w/ anticipated ↓ in condom use for insertive sex Multivariable Odds Ratio 1 95% CIP Would decrease condom use during INSERTIVE anal sex while using PrEP UAI in prior 3 mo.1.581.22-2.040.0005 Ever treated for drug/alcohol abuse 2.041.32-3.160.002 Aware of PEP1.230.99-1.530.07 UAI after ≥ 5 drinks 1.270.99-1.630.06 1 Adjusted for Age, race/ethnicity, education, income.

17. UAI, ↑ self-perceived risk, and UAI after ≥ 5 drinks were assoc. with anticipated ↓ in condom use for receptive sex Multivariable Odds Ratio 1 95% CIP Would decrease condom use during RECEPTIVE anal sex while using PrEP UAI in prior 3 mo. 1.571.16-2.130.004 Self-perceived risk of HIV acquisition 1.101.05-1.170.0003 UAI after ≥ 5 drinks 1.431.09-1.880.01 Positive screen for depression 1.310.99-1.740.06 1 Adjusted for Age, race/ethnicity, education, income.

18. In summary, a substantial minority of at-risk MSM anticipate decreased condom use while using PrEP MSM engaged in on-line networking report high- risk behaviors

19. In summary, a substantial minority of at-risk MSM anticipate decreased condom use while using PrEP MSM engaged in on-line networking report high- risk behaviors Interest in PrEP use exists: half would use daily PrEP

20. In summary, a substantial minority of at-risk MSM anticipate decreased condom use while using PrEP MSM engaged in on-line networking report high- risk behaviors Interest in PrEP use exists: half would use daily PrEP A substantial minority of MSM anticipate risk compensation for insertive (20%) or receptive (14%) anal sex while using PrEP

21. In summary, a substantial minority of at-risk MSM anticipate decreased condom use while using PrEP MSM engaged in on-line networking report high- risk behaviors Interest in PrEP use exists: half would use daily PrEP A substantial minority of MSM anticipate risk compensation for insertive (20%) or receptive (14%) anal sex while using PrEP Recent unprotected anal sex behaviors, greater self-perceived risk for HIV acquisition, and substance abuse are associated with anticipated risk compensation

22. Clinicians who prescribe PrEP to at-risk MSM should assess for changes in risky sexual behaviors More intensive counseling may be merited for MSM with recent risky behaviors increased self-perceived risk of HIV acquisition substance abuse

23. Clinicians who prescribe PrEP to at-risk MSM should assess for changes in risky sexual behaviors More intensive counseling may be merited for MSM with recent risky behaviors increased self-perceived risk of HIV acquisition substance abuse Studies to assess for risk compensation among persons using PrEP are needed

24. Abstract Authors Krakower, Douglas (Harvard Medical School/Beth Israel Deaconess Medical Center) Mimiaga, Matthew (Harvard Medical School/Massachusetts General Hospital and The Fenway Institute) Rosenberger, Joshua (George Mason University) Novak, David (Online Buddies, Inc., Cambridge, MA) Mitty, Jennifer A. (Harvard Medical School/Beth Israel Deaconess Medical Center and The Fenway Institute) White, Jaclyn (The Fenway Institute) Mayer, Ken (Harvard Medical School/Beth Israel Deaconess Medical Center and The Fenway Institute) Funding: Harvard T32 post-doctoral HIV Clinical Research Fellowship (NIAID AI 007433). Project support: Gilead Sciences. Thanks to the staff of the Fenway Institute, and the study participants.

25. Abstract Authors Krakower, Douglas (Harvard Medical School/Beth Israel Deaconess Medical Center) Mimiaga, Matthew (Harvard Medical School/Massachusetts General Hospital and The Fenway Institute) Rosenberger, Joshua (George Mason University) Novak, David (Online Buddies, Inc., Cambridge, MA) Mitty, Jennifer A. (Harvard Medical School/Beth Israel Deaconess Medical Center and The Fenway Institute) White, Jaclyn (The Fenway Institute) Mayer, Ken (Harvard Medical School/Beth Israel Deaconess Medical Center and The Fenway Institute) Funding: Harvard T32 post-doctoral HIV Clinical Research Fellowship (NIAID AI 007433). Project support: Gilead Sciences. Thanks to the staff of the Fenway Institute, and the study participants. Thank you! dkrakowe@bidmc.harvard.edu