309858
Augmenting self-reported smoking with biomarker data: Impact on prevalence estimation and measures of smoking-health associations
Cotinine is considered a “gold standard” biomarker for smoking. However, some researchers propose alternative biomarkers, such as 2,5-dimethylfuran (2DF), and others question the value of measuring biomarkers at all. We evaluated the impact of combining self-reported smoking and each of two smoking biomarkers on smoking prevalence and the estimated association between smoking and wheezing.
Methods
We analyzed data from 2,228 National Health and Nutrition Survey (2005-2006) participants with self-reported current smoking data and two serum smoking biomarkers (cotinine and 2,5-dimethylfuran). Cut-points for defining smoking were > 3.08 ng/mL for cotinine and 0.014 ng/mL for 2DF. Smoking prevalence was estimated using self-report alone and then augmented with biomarker data. We compared odds ratios for wheeze in the past year associated with each smoking measure adjusted for age, gender, and education.
Results
502 (23%) participants reported being current smokers. Inclusion of self-reported nonsmokers positive for smoking by cotinine increased smoking prevalence to 29%, while consideration of 2DF increased the prevalence to 24%. In adjusted models, self-reported smokers were more likely to report wheeze than nonsmokers (OR=2.45, 95% CI=1.87-3.20). The association did not change when adding 2DF to the definition (OR=2.45, 95% CI=1.89-3.19) and was modestly attenuated when adding cotinine (OR=2.32, 95% CI=1.80-3.01).
Conclusions
Of the two biomarkers examined, only cotinine modified smoking prevalence and effect estimates in a model of the effects of smoking on wheeze. Variation across measures could reflect underreporting, inappropriate biomarker cut-points, or differences in biomarker sensitivity. Measurement of cotinine and sensitivity analyses to estimate misclassification bias may be most beneficial in studies of populations that tend to under-report current smoking status.
Learning Areas:
EpidemiologyLearning Objectives:
Evaluate the impact of combining self-reported smoking and each of two smoking biomarkers on smoking prevalence and the estimated association between smoking and wheezing
Keyword(s): Tobacco Use, Epidemiology
Qualified on the content I am responsible for because: I am a leading analyst contracted to work on the Gulf Long-Term Follow-up Study -- an examination of the physical and mental health of oil spill clean-up workers. Smoking is a confounding variable in many of our analyses, as we have been studying different ways of measuring smoking in association with partners at the CDC to improve our understanding of VOCs in participants' blood.
Any relevant financial relationships? No
I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.