Reliability of self reported smoking status by pregnant women for estimating smoking prevalence: a retrospective, cross sectional study

• Published in: BMJ 2009-10, Vol.339 (7732), p.1241-1241
• Main Authors: Shipton, Deborah, Tappin, David M, Vadiveloo, Thenmalar, Crossley, Jennifer A, Aitken, David A, Chalmers, Jim
• Format: Article
• Language: English
• Subjects: Adult; Cessation; Cotinine - blood; Cross sectional studies; Epidemiologic Studies; Estimate reliability; Female; Health Education; Health Promotion; Humans; Methods; Pregnancy; Pregnancy Complications - blood; Pregnancy Complications - epidemiology; Pregnancy Trimester, Second; Pregnant women; Prenatal Care - methods; Prevalence; Reproducibility of Results; Reproductive Medicine; Scotland; Scotland - epidemiology; Screening (Epidemiology); Screening (Public Health); Second trimester of pregnancy; Secondhand smoke; Self Disclosure; Smoking; Smoking - blood; Smoking - epidemiology; Smoking and Tobacco; Smoking cessation; Smoking Cessation - statistics & numerical data; Socioeconomic Factors; Specialists; Studies; Tobacco smoking; Womens health; Womens health services; Young Adult
• ISSN: 0959-8138; 0959-535X; 1468-5833; 1756-1833
• DOI: 10.1136/bmj.b4347

Objective To determine what impact reliance on self reported smoking status during pregnancy has on both the accuracy of smoking prevalence figures and access to smoking cessation services for pregnant women in Scotland.Design Retrospective, cross sectional study of cotinine measurements in stored blood samples.Participants Random sample (n=3475) of the 21 029 pregnant women in the West of Scotland who opted for second trimester prenatal screening over a one year period.Main outcome measure Smoking status validated with cotinine measurement by maternal area deprivation category (Scottish Index of Multiple Deprivation).Results Reliance on self reported smoking status underestimated true smoking by 25% (1046/3475 (30%) from cotinine measurement v 839/3475 (24%) from self reporting, z score 8.27, P