title: Self-reported tobacco smoke exposure and plasma cotinine levels during pregnancy--a validation study in Northern Japan.
abstract: Maternal smoking is a critical public health concern requiring the establishment of its prevalence rate and clinical impact. Maternal self-reported information of tobacco smoke exposure requires validation using accurate biochemical analysis. This study examined the association between self-reported exposure to tobacco smoke and plasma cotinine level in Japanese pregnant women. We collected information about smoking and secondhand smoke (SHS) exposure during pregnancy from 5128 pregnant women in a prospective cohort design, and analyzed biochemically maternal blood samples using the enzyme-linked immunosorbent assay (ELISA) technique. Based on self-reports, the subjects were classified into three groups: 650 smokers, 728 ex-smokers and 3750 non-smokers. Using the receiver operating characteristic (ROC) curve, plasma cotinine cut-off value of 11.48 ng/mL was established for separating smokers from non-smokers, resulting in a smoking prevalence of 14%. A cotinine cut-off value of 0.21 ng/mL for discriminating exposed and unexposed nonsmokers resulted in a 63% prevalence of exposure to tobacco smoke among nonsmokers. Cotinine biomarker analysis proved accurate in validating self-reported smoking information in the subjects. Lower validity of SHS exposure suggests a need to confirm questionnaire information with biochemical analysis.
authors.affiliation: Department of Public Health, Hokkaido University Graduate School of Medicine, North 15 West 7, Sapporo 060-8638, Japan.
authors.forename: Seiko
authors.initials: S
authors.lastname: Sasaki
authors.forename: Titilola S
authors.initials: TS
authors.lastname: Braimoh
authors.forename: Thamar A
authors.initials: TA
authors.lastname: Yila
authors.forename: Eiji
authors.initials: E
authors.lastname: Yoshioka
authors.forename: Reiko
authors.initials: R
authors.lastname: Kishi
mesh_terms: D015331:Cohort Studies; D003367:Cotinine / Q000097:blood*; D004784:Environmental Monitoring / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D018811:Maternal Exposure / Q000009:adverse effects*; D011247:Pregnancy; D011446:Prospective Studies; D057566:Self Report; D012907:Smoking / Q000097:blood* / Q000453:epidemiology; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution; D003367:Cotinine