The accuracy of self-report of smoking status in pregnant women

Midwives' self-reports of smoking status of pregnant women are inaccurate, as they either misclassify or fail to identify a significant proportion of smokers. Midwife-identified nonsmokers who can be reclassified as smokers with research questionnaire and urinalysis methods, are 7.4% using the conservative estimate, 15.2% using the worst-case estimate, and 8.8% using the medium estimate. Findings suggest the need to improve the measures used to classify individuals.