title: Concordance between self-reported substance use and toxicology among HIV-infected and uninfected at risk youth.
abstract: BACKGROUND
  Substance use by youth living with HIV (YLWH) is a concern, given potential interactions with virus-associated immune suppression and adverse effects on risk behaviors, neurocognition, and adherence. Self-report substance use measures provide efficient cost-effective assessments. Analyses describe self-reported substance use among YLWH and examine agreement with toxicology assays.
  
  
  METHODS
  Seventy-eight youth age 18-24 years (87% male, 71% African-American) with behaviorally acquired HIV-1 infection and 55 uninfected youth completed the Alcohol, Smoking, and Substance Involvement Screening Test to assess drug use frequency, including tobacco, marijuana, cocaine, and alcohol, over the prior three months. Elisa-based toxicology assays were used to detect 27 substances in plasma. Chi-square tests compared substance use between YLWH and uninfected youth; Kappa statistics compared agreement between self-report and toxicology.
  
  
  RESULTS
  YLWH reported marijuana (49%), tobacco (56%), and alcohol (87%) use, with 20%, 28% and 3% reporting daily use of each substance, respectively; other substance use was uncommon. Uninfected youth reported less tobacco use but otherwise similar substance use. All youth who reported daily use of marijuana or tobacco had positive plasma toxicology results, while concordance decreased with less frequent self-reported use. Among youth reporting no substance use, few tested positive (4% YLWH, 2% uninfected youth for cannabis; 8%YLWH for tobacco).
  
  
  CONCLUSIONS
  Youth report high rates of marijuana, tobacco, and alcohol use. Concordance between self-report and toxicology for marijuana and tobacco use, particularly for daily users, supports self-report as a valid indicator of substance use in research studies of youth with or without HIV-1 infection.
authors.affiliation: Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, 92093 CA, USA. Electronic address: slnichols@ucsd.edu.
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Nichols
authors.affiliation: Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, PO Box 103633, Gainesville, 32610 FL, USA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Lowe
authors.affiliation: Department of Biostatistics, University of Florida, PO Box 103633, Gainesville, 32610 FL, USA.
authors.forename: Xinrui
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Consultant, PO Box 22814, Fort Lauderdale, 33335-2814 FL, USA.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Garvie
authors.affiliation: Westat, 1650 Research Blvd, Rockville, 20850 MD, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Thornton
authors.affiliation: Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, PO Box 103633, Gainesville, 32610 FL, USA.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Goldberger
authors.affiliation: Department of Preventive Medicine, Division of Epidemiology, Stony Brook University Medical Center, Stony Brook, 11794 NY, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Hou
authors.affiliation: Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, PO Box 103633, Gainesville, 32610 FL, USA.
authors.forename: Maureen M
authors.initials: MM
authors.lastname: Goodenow
authors.affiliation: Department of Pediatrics, Division of Allergy, Immunology, and Rheumatology, University of South Florida, St. Petersburg, 33701 FL, USA.
authors.forename: John W
authors.initials: JW
authors.lastname: Sleasman
mesh_terms: D000293:Adolescent; D015331:Cohort Studies; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D012309:Risk-Taking; D057566:Self Report / Q000592:standards*; D019966:Substance-Related Disorders / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology*; D055815:Young Adult
keywords: Adolescent; HIV; Marijuana; Self-report; Substance use; Toxicology