Misclassification of Smoking Habits as a Source of Bias in the Study of Environmental Tobacco Smoke and Lung Cancer

Abstract

The relationship of environmental tobacco smoke to lung cancer risk in lifelong non-smokers is commonly studied using marriage to a smoker as the index of exposure. As smokers tend to marry smokers, relative risk estimates will be biased if some current or former smokers are misclassified as lifelong non-smokers. This paper shows how various factors affect the magnitude of the bias and describes a method for obtaining misclassification-adjusted relative risk estimates. Application of the method to U.S. and Asian data for women suggests misclassification is an important determinant of the slight excess risk observed in non-smokers married to smokers. Reasons why our conclusions differ from those of others are discussed, as are other difficulties in interpreting the association between spousal smoking and lung cancer risk.

Complex segregation analysis reveals a multigene model for lung cancer

“…In addition, smoking status (ever vs. never) was used in our study. This could introduce some bias, because the risk of former smokers decreases over time (Lee and Forey 1996). However, the bias is expected to be small in our study because most of the ever-smokers are current smokers in our data set.…”

Factors affecting statistical power in the detection of genetic association

“…Thomas et al (75), Gustafson (76), and others provide an overview of issues and techniques (77)(78)(79)(80)(81). These works all deal with environmental as opposed to genetic association.…”

Environmental Tobacco Smoke Exposure and Risk of Stroke in Nonsmokers: A Review With Meta-analysis

“…31,32 Together, these two facts imply that studies of self-reported never smokers may observe that ETS is positively associated with risk of a disease caused by smoking even when no true risk of ETS exposure exists. 33 This misclassification bias has been widely discussed for lung cancer, although opinions differ as to its importance. 32,34-36 As smoking is Table 3.…”