title: Relative performance of common biochemical indicators in detecting cigarette smoking.
abstract: OBJECTIVE
  Many cities have banned indoor smoking in public places. Thus, an updated recommendation for a breath carbon monoxide (CO) cut-off is needed that optimally determines smoking status. We evaluated and compared the performance of breath CO and semiquantitative cotinine immunoassay test strips (urine and saliva NicAlert®) alone and in combination.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Urban drug addiction research and treatment facility.
  
  
  METHODS
  Ninety non-treatment-seeking smokers and 82 non-smokers.
  
  
  METHODS
  Participants completed smoking histories and provided breath CO, urine and saliva specimens. Urine and saliva specimens were assayed for cotinine by NicAlert® and liquid chromatography-tandem mass spectrometry (LCMSMS).
  
  
  RESULTS
  An optimal breath CO cut-off was established using self-report and LCMSMS analysis of cotinine, an objective indicator, as reference measures. Performance of smoking indicators and combinations were compared to the reference measures. Breath CO ≥5 parts per million (p.p.m.) optimally discriminated smokers from non-smokers. Saliva NicAlert® performance was less effective than the other indicators.
  
  
  CONCLUSIONS
  In surveys of smokers and non-smokers in areas with strong smoke-free laws, the breath carbon monoxide cut-off that discriminates most effectively appears to be ≥5 p.p.m. rather than the ≥10 p.p.m. cut-off often used. These findings may not generalize to clinical trials, regions with different carbon monoxide pollution levels or areas with less stringent smoke-free laws.
authors: Nicotine Psychopharmacology Section, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA.
authors: Gina F
authors: GF
authors: Marrone
authors: Diaa M
authors: DM
authors: Shakleya
authors: Karl B
authors: KB
authors: Scheidweiler
authors: Edward G
authors: EG
authors: Singleton
authors: Marilyn A
authors: MA
authors: Huestis
authors: Stephen J
authors: SJ
authors: Heishman
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001944:Breath Tests; D002248:Carbon Monoxide / Q000032:analysis*; D003367:Cotinine / Q000032:analysis* / Q000493:pharmacokinetics; D003430:Cross-Sectional Studies; D003627:Data Interpretation, Statistical; D005260:Female; D006207:Half-Life; D006801:Humans; D007118:Immunoassay / Q000592:standards; D008297:Male; D011933:Reagent Kits, Diagnostic / Q000592:standards*; D012015:Reference Standards; D012463:Saliva / Q000737:chemistry*; D057566:Self Report; D012680:Sensitivity and Specificity; D012907:Smoking / Q000331:legislation & jurisprudence / Q000378:metabolism*; D053719:Tandem Mass Spectrometry; D014028:Tobacco Smoke Pollution / Q000032:analysis* / Q000331:legislation & jurisprudence; D014505:Urban Population
chemical_list: D015415:Biomarkers; D011933:Reagent Kits, Diagnostic; D014028:Tobacco Smoke Pollution; D002248:Carbon Monoxide; D003367:Cotinine