UC Davis

Background

Lung cancer screening (LCS) for former and current smokers requires that current smokers are counseled on tobacco treatment. In the USA, over 4 million former smokers are estimated to be eligible for LCS based on self-report for "not smoking now." Tobacco use and exposure can be measured with the biomarker cotinine, a nicotine metabolite reflecting recent exposure.

Objective

To examine predictors of tobacco use and exposure among self-reported former smokers eligible for LCS.

Design

Cross-sectional study using the 2013-2018 National Health and Nutrition Examination Survey.

Participants

Former smokers eligible for LCS (n = 472).

Main measures

Recent tobacco use was defined as reported tobacco use in the past 5 days or a cotinine level above the race/ethnic cut points for tobacco use. Recent tobacco exposure was measured among former smokers without recent tobacco use and defined as having a cotinine level above 0.05 ng/mL.

Key results

One in five former smokers eligible for LCS, totaling 1,416,485 adults, had recent tobacco use (21.4%, 95% confidence interval (CI) 15.8%, 27.0%), with about a third each using cigarettes, e-cigarettes, or other tobacco products. Among former smokers without recent tobacco use, over half (53.0%, 95% CI: 44.6%, 61.4%) had cotinine levels indicating recent tobacco exposure. Certain subgroups had higher percentages for tobacco use or exposure, especially those having quit within the past 3 years or living with a household smoker.

Conclusions

Former smokers eligible for LCS should be asked about recent tobacco use and exposure and considered for cotinine testing. Nearly 1.5 million "former smokers" eligible for LCS may be current tobacco users who have been missed for counseling. The high percentage of "passive smokers" is at least double that of the general nonsmoking population. Counseling about the harms of tobacco use and exposure and resources is needed.