Comparing cotinine and NNAL verification of self-reported smoking status among lung cancer screening eligible population from the 2007–2014 National Health and Nutrition Examination Survey (NHANES)

Abstract

Background: Biochemical verification of self-reported smoking status is not common among the population eligible for lung cancer screening (LCS).

Methods: We used urinary NNAL (4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol and its glucuronides) and serum cotinine as the gold standard to determine the validity and reliability of self-reported smoking status from the 2007–2014 National Health and Nutrition Examination Survey (NHANES).

Results: We found 2.3% (n = 652, equivalent to 5.3 million weighted population) of adults eligible for LCS according to the current United States Preventive Services Task Force guideline. Self-reported current smoking status performed similarly against NNAL and cotinine: sensitivity [89.7% (95%CI: 84.9%–94.5%) vs. 89.5% (95%CI: 84.8%–94.3%)]; specificity [99.7% (95%CI: 99.2%–100.0%) vs. 100% (95%CI:100%–100%)]; positive predictive value (PPV) and negative predictive value (NPV) were 99.8% (95%CI:99.4%–100.0%) versus 100% (95%CI:100%–100%) and 85.3% (95%CI: 79.1%–91.5%) versus 85.1% (95%CI: 79.1%–1.0%), respectively; and Kappa [86.5% (95%CI:80.5%–92.5%) vs. 86.5% (95%CI:80.6%–92.3%)]. Performance measures were better among females than males; worst among the non-Hispanic white and best among other race/ethnicity group. The validity and reliability of self-reported smoking status increased with increasing cutpoint levels of both NNAL and cotinine.

Conclusions: Self-reported smoking status among people who are at high risk of lung cancer is reasonably reliable. The difference between using NNAL and cotinine appears to be minimal.

Keywords:

• Lung cancer
• screening
• biochemical validation
• self-report
• smoking

Acknowledgements

All authors have made substantial contribution to this work. The authors received no financial support for this work.

Disclosure statement

No potential conflict of interest was reported by the author(s).