NATIONAL INCIDENCE OF SMOKING AND MISCLASSIFICATION AMONG THE US MARRIED FEMALE-POPULATION

Because of a lack of representative data on smoking status misclassifi cation among U.S. married females, a two part study was conducted. Par t I was conducted to obtain nationally representative estimates of the percentage of U.S. women who report themselves to be current, former, and never smokers, to determine the concordance of smoking habits amo ng spouse pairs, and to establish field quotas and probability weighti ngs for Part II. Part II was conducted to determine smoker misclassifi cation rates using salivary cotinine as an indication of active smokin g. Part I, conducted in January 25-29, 1992, utilized random-digit dia ling telephone interviewing throughout the 48 contiguous United States . Part II, conducted from February 19, 1992 to March 7, 1992, was a ma ll-intercept study in nine geographically disperse U.S. cities and it involved interviewing and saliva collection. Among married U.S. women, 25% reported they were current smokers, 22% reported they were former smokers, and 53% reported they were never smokers. Using a cotinine c oncentration of either >35 ng/ml or >106 ng/ml to indicate regular smo king, 3.61% and 2.55% of regular smokers, respectively, reported thems elves to be never smokers. The concordance ratio, an important paramet er in correcting for non-differential misclassification bias, was foun d to be 5.52. In addition, an indication of substantial differential m isclassification was found between exposed and unexposed populations. This type of misclassification bias has previously not been accounted for in the adjustment of epidemiology-based risk assessments of tobacc o smoke exposure and lung cancer. Taken together, these data suggest t hat misclassification bias alone is likely to explain any lung cancer risk elevation observed in the U.S. epidemiology of environmental toba cco smoke exposure among non-smoking women. (C) 1997 Elsevier Science Inc.