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| Home > Articles > Published articles > Determinants of self-reported smoking and misclassification during pregnancy, and analysis of optimal cut-off points for urinary cotinine : |
| Home > Articles > Published articles > Determinants of self-reported smoking and misclassification during pregnancy, and analysis of optimal cut-off points for urinary cotinine : |
(Institut d'Investigació Biomèdica Sant Pau) (Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública) (Universidad de Oviedo)| Date: | 2013 |
| Abstract: | Objectives: To estimate the prevalence and factors associated with smoking and misclassification in pregnant women from INMA (INfancia y Medio Ambiente, Environment and Childhood) project, Spain, and to assess the optimal cut-offs for urinary cotinine (UC) that best distinguish daily and occasional smokers with varying levels of second-hand smoke (SHS) exposure. Design: We used logistic regression models to study the relationship between sociodemographic variables and self-reported smoking and misclassification (self-reported non-smokers with UC >50 ng/ml). Receiver operating characteristic (ROC) curves were used to calculate the optimal cut-off point for discriminating smokers. The cut-offs were also calculated after stratification among non-smokers by the number of sources of SHS exposure. The cut-off points used to discriminate smoking status were the level of UC given by Youden's index and for 50 and 100 ng/ml for daily smokers, or 25 and 50 ng/ml for occasional smokers. Participants: At the third trimester of pregnancy, 2263 pregnant women of the INMA Project were interviewed between 2004 and 2008 and a urine sample was collected. Results: Prevalence of self-reported smokers at the third trimester of pregnancy was 18. 5%, and another 3. 9% misreported their smoking status. Variables associated with self-reported smoking and misreporting were similar, including born in Europe, educational level and exposure to SHS. The optimal cut-off was 82 ng/ml (95% CI 42 to 133), sensitivity 95. 2% and specificity 96. 6%. The area under the ROC curve was 0. 986 (95% CI 0. 982 to 0. 990). The cut-offs varied according to the SHS exposure level being 42 (95% CI 27 to 57), 82 (95% CI 46 to 136) and 106 ng/ml (95% CI 58 to 227) for not being SHS exposed, exposed to one, and to two or more sources of SHS, respectively. The optimal cut-off for discriminating occasional smokers from non-smokers was 27 ng/ml (95% CI 11 to 43). Conclusions: Prevalence of smoking during pregnancy in Spain remains high. UC is a reliable biomarker for classifying pregnant women according to their smoking status. However, cut-offs would differ based on baseline exposure to SHS. |
| Grants: | Ministerio de Sanidad y Consumo 04/1436 Ministerio de Sanidad y Consumo 05/1079 Ministerio de Sanidad y Consumo 05/1052 Ministerio de Sanidad y Consumo 06/1213 Ministerio de Sanidad y Consumo 07/0314 Ministerio de Ciencia e Innovación 08/1151 Ministerio de Ciencia e Innovación 09/02311 Agència de Gestió d'Ajuts Universitaris i de Recerca 1999/SGR-00241 |
| Rights: | Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original.  |
| Language: | Anglès |
| Document: | Article ; recerca ; Versió publicada |
| Subject: | Epidemiology ; Public Health ; Toxicology ; Preventive Medicine |
| Published in: | BMJ open, Vol. 3 Núm. 1 (2013) , p. e002034, ISSN 2044-6055 |
