Smoking habits in the randomised Danish Lung Cancer Screening Trial with low-dose CT: final results after a 5-year
Haseem Ashraf1, Zaigham Saghir2, Asger Dirksen2
1Department of Respiratory Medicine, Gentofte University Hospital, Hellerup, Denmark Department of Radiology, Akershus University Hospital, Lørenskog, Norway.
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 Trials.gov Protocol Registration System (identification no. NCT00496977).
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