BACKGROUND: Objective validation of smoking status is necessary. Earlier studies have used saliva cotinine concentrations between 14.2 and 30 ng/ml as cut-off values to distinguish pregnant smokers from non-smokers. However, these cut-offs derive from studies including men and non-pregnant women. This constitutes a problem, as recent studies have reported an accelerated metabolism in pregnant smokers. The aim of this study was to determine the optimum cut-off cotinine level distinguishing pregnant smokers from pregnant non-smokers. METHODS: An observational study of 620 pregnant women, 359 self-reported smokers and 261 self-reported non-smokers, with complete data on smoking status and saliva cotinine. The study was conducted at a large university hospital in Copenhagen, Denmark. Saliva was sampled at the first antenatal visit to the midwife and analyzed for cotinine level by gas chromatography. Participants completed a questionnaire immediately after the first visit. RESULTS: A saliva cotinine cut-off level of 13 ng/ml, corresponding to a sensitivity of 0.99 and specificity 0.98, was found to be the optimum cut-off value separating pregnant smokers from non-smokers. The sum of the sensitivity and specificity was at its maximum, 1.981. A 95% bootstrap confidence interval for the optimum cut-off was (8-14 ng/ml). CONCLUSION: From the present data we recommend that in future studies on smoking cessation and pregnancy a cut-off level of 13 ng/ml should be applied to distinguish between pregnant smokers and non-smokers.
BACKGROUND: Objective validation of smoking status is necessary. Earlier studies have used saliva cotinine concentrations between 14.2 and 30 ng/ml as cut-off values to distinguish pregnant smokers from non-smokers. However, these cut-offs derive from studies including men and non-pregnant women. This constitutes a problem, as recent studies have reported an accelerated metabolism in pregnant smokers. The aim of this study was to determine the optimum cut-off cotinine level distinguishing pregnant smokers from pregnant non-smokers. METHODS: An observational study of 620 pregnant women, 359 self-reported smokers and 261 self-reported non-smokers, with complete data on smoking status and saliva cotinine. The study was conducted at a large university hospital in Copenhagen, Denmark. Saliva was sampled at the first antenatal visit to the midwife and analyzed for cotinine level by gas chromatography. Participants completed a questionnaire immediately after the first visit. RESULTS: A saliva cotinine cut-off level of 13 ng/ml, corresponding to a sensitivity of 0.99 and specificity 0.98, was found to be the optimum cut-off value separating pregnant smokers from non-smokers. The sum of the sensitivity and specificity was at its maximum, 1.981. A 95% bootstrap confidence interval for the optimum cut-off was (8-14 ng/ml). CONCLUSION: From the present data we recommend that in future studies on smoking cessation and pregnancy a cut-off level of 13 ng/ml should be applied to distinguish between pregnant smokers and non-smokers.
Authors: Teresa R Gray; Rina D Eiden; Kenneth E Leonard; Gerard Connors; Shannon Shisler; Marilyn A Huestis Journal: Nicotine Tob Res Date: 2010-04-28 Impact factor: 4.244
Authors: Neal L Benowitz; John T Bernert; Jonathan Foulds; Stephen S Hecht; Peyton Jacob; Martin J Jarvis; Anne Joseph; Cheryl Oncken; Megan E Piper Journal: Nicotine Tob Res Date: 2020-06-12 Impact factor: 4.244
Authors: Tatjana Lazic; Milan Matic; Jack M Gallup; Albert Van Geelen; David K Meyerholz; Branka Grubor; Paula M Imerman; Marcia M M A de-Macedo; Mark R Ackermann Journal: Pediatr Pulmonol Date: 2010-03
Authors: Lorien C Abroms; Pamela R Johnson; Leah E Leavitt; Sean D Cleary; Jessica Bushar; Thomas H Brandon; Shawn C Chiang Journal: Am J Prev Med Date: 2017-10-02 Impact factor: 5.043
Authors: Allison N Kurti; Katherine Tang; Hypatia A Bolivar; Carolyn Evemy; Norman Medina; Joan Skelly; Tyler Nighbor; Stephen T Higgins Journal: Prev Med Date: 2020-07-09 Impact factor: 4.018
Authors: Catherine Chamberlain; Alison O'Mara-Eves; Sandy Oliver; Jenny R Caird; Susan M Perlen; Sandra J Eades; James Thomas Journal: Cochrane Database Syst Rev Date: 2013-10-23