title: Reliability of homeless women's reports: concordance between hair assay and self report of cocaine use.
abstract: BACKGROUND
  To assess the concordance of homeless women's self-reported drug use with objective data.
  
  
  OBJECTIVE
  To determine whether objective data (e.g., hair assays) are necessary supplements to self reports in assessing homeless women's cocaine use.
  
  
  METHODS
  Self reports of cocaine use by 1,037 homeless women were compared to objective data based on radioimmunoassay of hair; independent correlates of cocaine use and underreporting were assessed using logistic regression.
  
  
  RESULTS
  Forty-two percent of the women self-reported cocaine use in the past 6 months, whereas 49% had positive hair assays. Over 25% underreported cocaine use; however, underreporting decreased as hair cocaine levels increased. Predictors of underreporting included being Latino, younger and living primarily in shelters. Nevertheless, independent predictors of self-reported cocaine use and positive hair assays were identical.
  
  
  CONCLUSIONS
  Homeless women's self-reports of cocaine use are fairly accurate. Objective data are particularly critical for assessing cocaine use among subgroups who are fearful of sanctions or use cocaine relatively infrequently or in smaller amounts.
authors.affiliation: School of Nursing, University of California Los Angeles, CA 90095-1702, USA.
authors.forename: A
authors.initials: A
authors.lastname: Nyamathi
authors.forename: B
authors.initials: B
authors.lastname: Leake
authors.forename: D
authors.initials: D
authors.lastname: Longshore
authors.forename: L
authors.initials: L
authors.lastname: Gelberg
mesh_terms: D000328:Adult; D019970:Cocaine-Related Disorders / Q000453:epidemiology*; D004522:Educational Status; D005260:Female; D006197:Hair / Q000737:chemistry*; D006703:Ill-Housed Persons; D006801:Humans; D016015:Logistic Models; D015141:Los Angeles / Q000453:epidemiology; D011863:Radioimmunoassay; D015203:Reproducibility of Results; D012650:Self Disclosure