title: Plasma cotinine: stability in smokers and validation of self-reported smoke exposure in nonsmokers.
abstract: The stability of plasma cotinine was studied in smokers and the validity of a brief questionnaire on environmental tobacco smoke (ETS) exposure was assessed in nonsmokers. The correlation between two cotinine levels measured 14 weeks apart was 0.81 in smokers (n = 148). A single measurement will classify 95% of all subjects within 30% of their habitual plasma cotinine level. Plasma cotinine was higher in ETS-exposed nonsmokers (n = 50) than in ETS-unexposed nonsmokers (n = 55; 1.6 ng/ml vs 0.6 ng/ml; P < 0.0001), but there was a substantial part of intersubject overlap. The sensitivity and specificity with respect to self-reported smoke exposure were 56 and 89%, respectively. This study shows that a single plasma cotinine determination gives a good impression of cotinine levels. It is dubious if a brief questionnaire about hours of passive smoke exposure in nonsmokers is valid to distinguish ETS-exposed from ETS-unexposed nonsmokers.
authors.affiliation: Department of Human Nutrition, TNO-Toxicology and Nutrition Institute, Zeist, The Netherlands.
authors.forename: J M
authors.initials: JM
authors.lastname: Kemmeren
authors.forename: G
authors.initials: G
authors.lastname: van Poppel
authors.forename: P
authors.initials: P
authors.lastname: Verhoef
authors.forename: M J
authors.initials: MJ
authors.lastname: Jarvis
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D003367:Cotinine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D012907:Smoking / Q000097:blood*; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution
chemical_list: D014028:Tobacco Smoke Pollution; D003367:Cotinine