title: Drug Use, Sexual Risk, and Syndemic Production Among Men Who Have Sex With Men Who Engage in Group Sexual Encounters.
abstract: OBJECTIVE
  We surveyed men who have sex with men (MSM) to determine whether sexual risk behaviors, recent drug use, and other psychosocial problems differed between men who engaged in one-on-one and group sexual encounters.
  
  
  METHODS
  We conducted an Internet-based cross-sectional survey of 7158 MSM aged 18 years or older in the United States recruited from a gay-oriented sexual networking Web site in 2008. Among MSM who engaged in group sexual encounters, we compared their past-60-day sexual behaviors in one-on-one encounters and group sexual encounters. We also compared risk profiles and syndemic production between men who did and did not participate in group sex.
  
  
  RESULTS
  Men reporting a group-sex encounter had significantly higher polydrug use and sexual risk than did the men not reporting group sex in the past 60 days. The odds of engaging in group sex with 4 or more sexual partners significantly increased with the number of psychosocial problems, supporting evidence of syndemic production.
  
  
  CONCLUSIONS
  We identified a particularly high-risk subgroup in the MSM population with considerable psychosocial problems that may be reached online. Research is needed on how to engage these high-risk men in combination prevention interventions.
authors.affiliation: Sabina Hirshfield, Martin J. Downing Jr, and Mary Ann Chiasson are with Public Health Solutions, Research and Evaluation Unit, New York, NY. Eric W. Schrimshaw is with the Department of Sociomedical Sciences, Mailman School of Public Health, Columbia University, New York. Ronald D. Stall is with the Department of Behavioral and Community Health Sciences, School of Public Health, University of Pittsburgh, Pittsburgh, PA. Andrew D. Margolis is with the Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Division of HIV/AIDS Prevention, Prevention Research Branch, Atlanta, GA.
authors.forename: Sabina
authors.initials: S
authors.lastname: Hirshfield
authors.affiliation: Sabina Hirshfield, Martin J. Downing Jr, and Mary Ann Chiasson are with Public Health Solutions, Research and Evaluation Unit, New York, NY. Eric W. Schrimshaw is with the Department of Sociomedical Sciences, Mailman School of Public Health, Columbia University, New York. Ronald D. Stall is with the Department of Behavioral and Community Health Sciences, School of Public Health, University of Pittsburgh, Pittsburgh, PA. Andrew D. Margolis is with the Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Division of HIV/AIDS Prevention, Prevention Research Branch, Atlanta, GA.
authors.forename: Eric W
authors.initials: EW
authors.lastname: Schrimshaw
authors.affiliation: Sabina Hirshfield, Martin J. Downing Jr, and Mary Ann Chiasson are with Public Health Solutions, Research and Evaluation Unit, New York, NY. Eric W. Schrimshaw is with the Department of Sociomedical Sciences, Mailman School of Public Health, Columbia University, New York. Ronald D. Stall is with the Department of Behavioral and Community Health Sciences, School of Public Health, University of Pittsburgh, Pittsburgh, PA. Andrew D. Margolis is with the Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Division of HIV/AIDS Prevention, Prevention Research Branch, Atlanta, GA.
authors.forename: Ronald D
authors.initials: RD
authors.lastname: Stall
authors.affiliation: Sabina Hirshfield, Martin J. Downing Jr, and Mary Ann Chiasson are with Public Health Solutions, Research and Evaluation Unit, New York, NY. Eric W. Schrimshaw is with the Department of Sociomedical Sciences, Mailman School of Public Health, Columbia University, New York. Ronald D. Stall is with the Department of Behavioral and Community Health Sciences, School of Public Health, University of Pittsburgh, Pittsburgh, PA. Andrew D. Margolis is with the Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Division of HIV/AIDS Prevention, Prevention Research Branch, Atlanta, GA.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Margolis
authors.affiliation: Sabina Hirshfield, Martin J. Downing Jr, and Mary Ann Chiasson are with Public Health Solutions, Research and Evaluation Unit, New York, NY. Eric W. Schrimshaw is with the Department of Sociomedical Sciences, Mailman School of Public Health, Columbia University, New York. Ronald D. Stall is with the Department of Behavioral and Community Health Sciences, School of Public Health, University of Pittsburgh, Pittsburgh, PA. Andrew D. Margolis is with the Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Division of HIV/AIDS Prevention, Prevention Research Branch, Atlanta, GA.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Downing
authors.affiliation: Sabina Hirshfield, Martin J. Downing Jr, and Mary Ann Chiasson are with Public Health Solutions, Research and Evaluation Unit, New York, NY. Eric W. Schrimshaw is with the Department of Sociomedical Sciences, Mailman School of Public Health, Columbia University, New York. Ronald D. Stall is with the Department of Behavioral and Community Health Sciences, School of Public Health, University of Pittsburgh, Pittsburgh, PA. Andrew D. Margolis is with the Centers for Disease Control and Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Division of HIV/AIDS Prevention, Prevention Research Branch, Atlanta, GA.
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Chiasson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D018451:Homosexuality, Male / Q000706:statistics & numerical data*; D006801:Humans; D020407:Internet; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D012309:Risk-Taking; D012725:Sexual Behavior / Q000706:statistics & numerical data*; D012747:Sexual Partners; D019966:Substance-Related Disorders / Q000453:epidemiology*; D014481:United States / Q000453:epidemiology; D047568:Unsafe Sex / Q000706:statistics & numerical data*