title: Clear Links Between Starting Methamphetamine and Increasing Sexual Risk Behavior: A Cohort Study Among Men Who Have Sex With Men.
abstract: BACKGROUND
  It remains unclear if methamphetamine is merely associated with high-risk behavior or if methamphetamine use causes high-risk behavior. Determining this would require a randomized controlled trial, which is clearly not ethical. A possible surrogate would be to investigate individuals before and after starting the use of methamphetamine.
  
  
  METHODS
  We performed a cohort study to analyze recent self-reported methamphetamine use and sexual risk behavior among 8905 men who have sex with men (MSM) receiving the "Early Test," a community-based HIV screening program in San Diego, CA, between April 2008 and July 2014 (total 17,272 testing encounters). Sexual risk behavior was evaluated using a previously published risk behavior score [San Diego Early Test (SDET) score] that predicts risk of HIV acquisition.
  
  
  RESULTS
  Methamphetamine use during the last 12 months (hereafter, recent-meth) was reported by 754/8905 unique MSM (8.5%). SDET scores were significantly higher in the 754 MSM with recent-meth use compared with the 5922 MSM who reported that they have never used methamphetamine (P < 0.001). Eighty-two repeat testers initiated methamphetamine between testing encounter, with significantly higher SDET scores after starting methamphetamine [median 5 (interquartile range, 2-7) at recent-meth versus median 3 (interquartile range, 0-5) at never-meth; P < 0.001, respectively].
  
  
  CONCLUSIONS
  Given the ethical impossibility of conducting a randomized controlled trial, the results presented here provide the strongest evidence yet that initiation of methamphetamine use increases sexual risk behavior among HIV-uninfected MSM. Until more effective prevention or treatment interventions are available for methamphetamine users, HIV-uninfected MSM who use methamphetamine may represent ideal candidates for alternative effective prevention interventions (ie, preexposure prophylaxis).
authors.affiliation: *Division of Infectious Diseases, Department of Medicine, University of California San Diego (UCSD), La Jolla, San Diego, CA; †Section of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Medical University of Graz, Graz, Austria; ‡Division of Pulmonology, Department of Internal Medicine, Medical University of Graz, Graz, Austria; §Department of Psychiatry, University of California San Diego (UCSD), La Jolla, San Diego, CA; and ‖Veterans Affairs Healthcare System, San Diego, CA.
authors.forename: Martin
authors.initials: M
authors.lastname: Hoenigl
authors.forename: Antoine
authors.initials: A
authors.lastname: Chaillon
authors.forename: David J
authors.initials: DJ
authors.lastname: Moore
authors.forename: Sheldon R
authors.initials: SR
authors.lastname: Morris
authors.forename: Davey M
authors.initials: DM
authors.lastname: Smith
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Little
mesh_terms: D000328:Adult; D019969:Amphetamine-Related Disorders / Q000150:complications*; D015331:Cohort Studies; D015658:HIV Infections / Q000517:prevention & control; D018451:Homosexuality, Male / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008694:Methamphetamine / Q000009:adverse effects*; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D012309:Risk-Taking; D047568:Unsafe Sex / Q000706:statistics & numerical data*
chemical_list: D008694:Methamphetamine