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Trends in HIV prevalence and HIV testing among young MSM – five United States cities, 1994-2008.
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Trends in HIV prevalence and HIV testing among young MSM – five United States cities, 1994-2008 Alexandra M. Oster, MD, Christopher Johnson, MS, Binh Le, MD, Teresa Finlayson, MPH, PhD, Alexandra Balaji, PhD, Amy Lansky, MPH, PhD, Jonathan Mermin, MD, MPH, Linda Valleroy, PhD, Duncan MacKellar, DrPH, Stephanie Behel, MPH, Gabriela Paz-Bailey, MD, PhD, MSc for the YMS and NHBS Study Groups Division of HIV/AIDS Prevention Centers for Disease Control and Prevention Atlanta, GA, United States AIDS 2012 Abstract MOAC0104 July 23, 2012 The findings and conclusions in this presentation are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention. National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention Division of HIV/AIDS Prevention
Background: HIV incidence among young MSM From 2006 to 2009, new infections increased 34% among MSM aged 13-29y in the United States Another method for examining incidence is using serial cross-sectional measurements of prevalence Among young people, these measurements of prevalence can serve as proxy for incidence *PrejeanPLoS ONE 2011
Background: HIV testing among young MSM HIV testing and diagnosis allow for behavioral changes and clinical treatment to optimize outcomes and reduce transmission risk Increasing percentage of HIV-infected persons who are aware of their serostatus is a key objective of U.S. National HIV/AIDS Strategy Important to monitor HIV testing behaviors over time
Objective Assess trends among young MSM in the United States from 1994–2008 for two indicators: HIV prevalence HIV testing behavior
Data sources Young Men’s Survey (YMS) National HIV Behavioral Surveillance System among Men Who Have Sex with Men (NHBS-MSM) MacKellar DA et al. JAIDS 2005 MacKellar DA et al. Public Health Reports 2007
Data sources NHBS-MSM1 2003-2005 ≥18 y 5* Study Dates Age range # cities YMS Phase I 1994-1998 15-22 y 7 YMS Phase II 1998-2000 23-29 y 7 NHBS-MSM2 2008 ≥18 y 21 *NHBS-MSM1 included surveys in 15 cities but HIV testing in only 5.
YMS and NHBS data collection • Venue-based sampling • Standardized in-person anonymous interview • Anonymous HIV testing • All participants offered an HIV test • Incentives for interview and HIV testing
Venue-based sampling • Formative research • Identification of venues and day-time periods • Random selection of venues and day-time periods • Recruit, interview, and test participants at randomly selected venues during sampled day-time periods
Eligibility criteria • Resident of metropolitan statistical area (MSA) • Able to complete interview in English or Spanish • Male sex at birth and identifies as male* *NHBS only; YMS included transgender persons
Analysis criteria • Aged 18-29 years • Male sex partner during past 6 months • Did not identify as transgender • 5 MSAs that participated in all studies • 4 MSAs for analyses of men aged 23-29 y • For analyses of HIV testing behavior, we also excluded men who self-reported a previous positive HIV test
MSAs included in analysis* New York City San Francisco Baltimore Los Angeles Miami *San Francisco excluded from analyses for men aged 23-29 y.
Analytic methods • Combined data from all studies • Separate analysis by age group • 18-22 years • 23-29 years • Assessed temporal trends for each age group in • HIV prevalence • HIV testing in past 12 months* *among men not reporting a previous positive test
Multivariable modeling methods • Created multivariable logistic regression model for each outcome with each age group (4 models total) • Interview year as linear variable • MSA and race/ethnicity as covariates in all models • Education as covariate in models for men aged 23-29 y • Calculated model-adjusted estimates of HIV prevalence and HIV testing from predicted marginals
Race/ethnicity among young MSM, YMS and NHBS, 1994-2008 18-22 years 23-29 years
Education among young MSM, YMS and NHBS,1994-2008 18-22 years 23-29 years
Sexual identity, young MSM, YMS and NHBS,1994-2008 18-22 years 23-29 years
HIV prevalence, young MSM, YMS and NHBS,1994-2008 18-22 years 23-29 years
Model-adjusted* HIV prevalence among young MSM, Young Men’s Survey & National HIV Behavioral Surveillance System p=0.07 p=0.6 *Adjusted for MSA, race/ethnicity, and, for MSM aged 23-29 years, education.
Recent HIV testing (past 12 mo) among young MSM,* YMS and NHBS,1994-2008 18-22 years 23-29 years *Excluding men who reported a previous positive HIV test.
Model-adjusted* HIV testing among young MSM,Young Men’s Survey & National HIV Behavioral Surveillance System p<0.0001 p<0.0001 *Adjusted for MSA, race/ethnicity, and, for MSM aged 23-29 years, education.
Summary • HIV prevalence • Was stable among MSM aged 18-22 years (1994-2008) • May have increased among MSM aged 23-29 years (1998-2008) • HIV testing increased substantially among both age groups
Analysis limitations • Social desirability bias may affect estimates • Date of most recent HIV test was self-reported • Not representative of all MSM • Data collected in 4-5 MSAs with high AIDS prevalence • Most men were recruited from bars or dance clubs • Sampling methods may result in selection bias • Data are not weighted to account for bias
Discussion: HIV prevalence • Prevalence was high among young MSM in 4-5 MSAs • Consistent with national data • Stable prevalence among 18-22 year old MSM • Suggests stable incidence over time • Increasing prevalence among 23-29 year old MSM, although trend was not statistically significant • Suggestive of possible increase in incidence • We are exploring adding more recent data to see if trend continues
Discussion: HIV testing • Recent HIV testing increased substantially among MSM of both age groups • May reflect effect of CDC initiatives
Conclusions • Gains in HIV testing among young MSM are encouraging • Data from multiple surveillance systems can be used to • Characterize epidemic • Triangulate findings on epidemiologic measures (incidence, prevalence, HIV testing behaviors) • Monitor changes over time • To prevent ongoing transmission and improve health of people living with HIV, it is important that young MSM are • Tested regularly • Aware of their infection • Linked and engaged in appropriate care
Acknowledgements YMS Study Group:Trista Bingham, David Celentano, Beryl Koblin, Marlene LaLota, Willi McFarland, Gina Secura, Lucia Torian NHBS Study Group: Trista Bingham, Colin Flynn, Holly Hagan, Beryl Koblin, Marlene LaLota, Willi McFarland, Lisa Metsch, Chris Murrill, Alan Neaigus, H. Fisher Raymond, FrangiscosSifakis, Travis Wendel Behavioral Surveillance Team, CDC YMS and NHBS Participants
Alexa Oster, MD Medical Epidemiologist Behavioral and Clinical Surveillance Branch AOster@cdc.gov National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention Division of HIV/AIDS Prevention