Smoking habits in the randomised Danish Lung Cancer Screening Trial with low-dose CT: final results after a 5-year screening programme

Thorax. 2014 Jun;69(6):574-9. doi: 10.1136/thoraxjnl-2013-203849. Epub 2014 Jan 17.


Background: We present the final results of the effect of lung cancer screening with low-dose CT on the smoking habits of participants in a 5-year screening trial.

Methods: The Danish Lung Cancer Screening Trial (DLCST) was a 5-year screening trial that enrolled 4104 subjects; 2052 were randomised to annual low-dose CT (CT group) and 2052 received no intervention (control group). Participants were current and ex-smokers (≥4 weeks abstinence from smoking) with a tobacco consumption of ≥20 pack years. Smoking habits were determined annually. Missing values for smoking status at the final screening round were handled using two different models.

Results: There were no statistically significant differences in annual smoking status between the CT group and control group. Overall the ex-smoker rates (CT + control group) significantly increased from 24% (baseline) to 37% at year 5 of screening (p<0.001). The annual point prevalence quit rate increased from 11% to 24% during the five screening rounds; the ex-smokers' relapse rate remained stable, around 11%, across the same period.

Conclusions: Screening with low-dose CT had no extra effect on smoking status compared with the control group, but overall the screening programme probably promoted smoking cessation.

Clinical trial registration: The DLCST is registered in Clinical Protocol Registration System (identification no. NCT00496977).

Keywords: Lung Cancer; Tobacco and the lung.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Denmark / epidemiology
  • Early Detection of Cancer / methods*
  • Early Detection of Cancer / psychology
  • Female
  • Humans
  • Lung Neoplasms / diagnostic imaging*
  • Lung Neoplasms / mortality
  • Lung Neoplasms / psychology
  • Male
  • Middle Aged
  • Motivation*
  • Prevalence
  • Radiation Dosage
  • Smoking / epidemiology*
  • Smoking / psychology
  • Smoking Cessation / psychology
  • Smoking Cessation / statistics & numerical data*
  • Tomography, X-Ray Computed

Associated data