Usefulness of Urinary Cotinine Test to Discriminate between Smokers and Nonsmokers in Korean Adolescents / 대한진단검사의학회지

ABSTRACT

BACKGROUND: Recently we have demonstrated that urinary cotinine test by an enzyme immunoassay is valid to discriminate smoking status among adults. This study was conducted for the same purpose among Korean high school students. METHODS: Questionnaire on smoking and urinary cotinine tests were performed for 1, 267 high school students. Cotinine concentrations in urine were measured by Cotinine Enzyme Immunoassay (Diag-nostic Reagents Inc., CA, USA) on 502X Multiple Chemistry Unit (A&T Co., Tokyo, Japan). RESULTS: The questionnaire was responded by 1, 227 of the 1, 267 students (96.8%); 6 male (0.8%) and 34 female students (5.9%) did not respond. Among the responders, 13.4% (92/685) of male students and 3.0% (16/542) of female students answered as smokers. By using 6 ng/mL as a cutoff, the sensitivity and specificity of the urinary cotinine test were 79.6% (86/108) and 91.4% (1023/1119), respectively. According to the results of urinary cotinine, 96 additional students were presumed as smokers. Of 85 abstainers and 40 non-responders, 41 (32.8%) tested positive for urinary cotinine. CONCLUSIONS: Unlike in a previous study with adults, the urinary cotinine test is shown not to be able to replace the self-reported questionnaire due to the lack of sensitivity for young adolescents. But the urinary continine test is valid to discriminate smokers among purported nonsmokers, espe-cially among non-responders and those who claimed abstinence.