National Cancer Institute Smoking Cessation at Lung Examination Trials Brief Report: Baseline Characteristics and Comparison With the U.S. General Population of Lung Cancer Screening-Eligible Patients

Introduction: The National Cancer Institute Smoking Cessation at Lung Examination (SCALE) Collaboration includes eight clinical trials testing smoking cessation interventions delivered with lung cancer screening (LCS). This investigation compared pooled participant baseline demographic and smoking characteristics of seven SCALE trials to LCS-eligible smokers in three U.S. nationally representative surveys.

Methods: Baseline variables (age, sex, race, ethnicity, education, income, cigarettes per day, and time to the first cigarette) from 3614 smokers enrolled in SCALE trials as of September 2020 were compared with pooled data from the Tobacco Use Supplement-Current Population Survey (2018-2019), National Health Interview Survey (2017-2018), and Population Assessment of Tobacco and Health (wave 4, 2016-2017) using the U.S. Preventive Services Task Force 2013 (N = 4803) and 2021 (N = 8604) LCS eligibility criteria.

Results: SCALE participants have similar average age as the U.S. LCS-eligible smokers using the 2013 criteria but are 2.8 years older using the 2021 criteria (p < 0.001). SCALE has a lower proportion of men, a higher proportion of Blacks, and slightly higher education and income levels than national surveys (p < 0.001). SCALE participants smoke an average of 17.9 cigarettes per day (SD 9.2) compared with 22.4 (SD 9.3) using the 2013 criteria and 19.6 (SD 9.7) using the 2021 criteria (p < 0.001). The distribution of time to the first cigarette differs between SCALE and the national surveys (p < 0.001), but both indicate high levels of nicotine dependence.

Conclusions: SCALE participants smoke slightly less than the LCS-eligible smokers in the general population, perhaps related to socioeconomic status or race. Other demographic variables reveal small but statistically significant differences, likely of limited clinical relevance with respect to tobacco treatment outcomes. SCALE trial results should be applicable to LCS-eligible smokers from the U.S. population.