MedicalResearch.com Interview with:
Perry N Halkitis, Ph.D., M.S., MPH
Professor of Applied Psychology
Global Public Health, and Population Health/Medicine
New York University.
Medical Research: What is the background for this study?
Dr. Halkitis: The P18 Cohort Study is a prospective cohort study of gay, bisexual and other young men who have sex with men (YMSM) which seeks to examine the development of health behaviors as these young men transition from adolescent to adulthood. Officially named “Syndemic Production among Emergent Adult Men”, this study was funded by the National Institute on Drug Abuse from 2009-2014 and renewed on March 1, 2014 for an additional five years.
The original aims of the study were as follows:
- 1) to develop and test theoretically informed measurement models of the covariance of illicit drug use, unprotected sexual behavior and mental health burden (multiple overlapping epidemics known as a syndemic) among emergent adult HIV-negative YMSM within and across time;
- 2) to delineate the risk and protective bases- physical factors (e.g., pubertal onset, HIV status, etc.), relational and structural factors (e.g., family history of psychopathology, current romantic relationships, peer support, neighborhood factors, etc.), and psychosocial factors (e.g., sexual identity, internalized homophobia, hyper-masculine conceptions, etc.) that predict the development of syndemics; and
- 3) to determine the extent to which the development of a syndemic varies by race/ethnicity, social class, and homelessness/housing instability.
- In this current five year continuation we also seek
- 1) to describe the social and sexual networks of YMSM, and to examine the relationship between social and sexual network-level structural characteristics, social support and normative influences on syndemic production (illicit drug use, unprotected sexual behaviors, and mental health burden) in YMSM, singly and in combination with the physical, psychosocial, and relational predictors, both within and across time;
- 2) to describe the acquisition of sexually transmitted infections (STIs) in YMSM, specifically, urethral and rectal gonorrhea and chlamydia, pharyngeal gonorrhea as well as syphilis serology; and to determine the extent to which physical, relational, and psychosocial factors explain STI acquisition as part of the syndemic model within and across time.
- A third exploratory aim was also added: 3) to describe HIV clinical treatment markers (i.e., HIV viral load, ART uptake and adherence, HIV care) among HIV+ YMSM, and to assess the extent to which physical, relational, and psychosocial factors are associated with differences in these clinical markers among HIV+ YMSM, both within and across time. The study is led by Drs. Perry N Halkitis and Farzana Kapadia at New York University’s Center for Health, Identity, Behavior & Prevention Studies.
Potential participants were recruited through both active (e.g., approaching individuals to solicit study participation) and passive (e.g., flyer posting, website advertisements) methods from June 2009 to May 2011. Eligibility criteria included being 18-19 years old, biologically male, residing in the NYC metropolitan area, having sex (any physical contact that could lead to orgasm) with a man in the last 6 months, and reporting a seronegative or unknown HIV status at baseline. We ensured the diversity of our sample by setting a fixed recruitment quota for participants in each targeted racial/ethnic group, such that African Americans, Latino (across race), Asian-Pacific Islander (API), and mixed race men comprised the majority of the sample. All participants provided written, informed consent before data was collected and were compensated for their time and effort upon completing the baseline assessment. The New York University’s Institutional Review Board (IRB) approved all study protocols and a federal Certificate of Confidentiality protects these data.
A total of 2,068 participants were screened for eligibility to participate in the study, and 600 participants completed the baseline assessment in the first wave of the study. In 2014, we began the second wave and opened to cohort to recruit a baseline sample of 650 YMSM who will now be between the ages of 22-23; recruitment of participants is still underway.
Medical Research: What are the main findings?
Dr. Halkitis: Numerous publications have been generated from the P18 Cohort Study and can be accessed at www.chibps.org. A recent publication, “Incidence of HIV infection in Young Gay, Bisexual, and other YMSM: The P18 Cohort Study” became available in the May 2015 of JAIDS, the Journal of Acquired Immune Deficiency Syndromes. This paper reports that over a 36 month follow-up period, during the first wave of the study, 7.2% of study participants seroconverted, with Black and Hispanic men much more likely to seroconvert over this time frame than White men. This finding aligns with epidemiological trends for HIV infection at the national and local, NYC, levels. Also, men reporting a lower familial socioeconomic status were more likely to seroconvert than men reporting high familial socioeconomic status, and Black men were more likely to report a lower socioeconomic status. Moreover, the Black young men who seroconverted were more likely to reside in neighborhoods with higher area-level poverty and higher area-level HIV prevalence. Additionally we found that men who reported anal sex without a condom in the 30 days prior to assessment were no more likely to seroconvert than those who reported sex with a condom. However, an earlier age of sexual debut was a predictor of HIV seroconversion.