Effect of smoking cessation counseling within a randomised study on early detection of lung cancer in Germany

In the German lung cancer screening trial LUSI, smoking cessation counseling (SCC) was offered to all participants at time of randomization, and smoking habits were asked for within annual questionnaire inquiries. We analyzed the smoking habits of the participants within the first 2 years of follow-up and especially the potential effect of the SCC on these habits. We used the smoking data of the initial inquiry on which the decision on invitation to the study was based, the socio-economic data of the questionnaire filled-in at time of randomization, the psycho-social data obtained during the SCC, and the annual questionnaire data of the first two annual follow-up screening rounds. Smoking prevalence decreased in the entire cohort significantly by 4 %, whereby the decrease was with 4.5 % statistically not significantly higher in the control arm than in the screening arm with 3.4 %. The decline was much stronger in the subgroup of attendees to stop-smoking counseling and mounted up therein to 10 %. In some participants, an increase of readiness to quit smoking was observed during the counseling hour, but did not show effects on smoking status 2 years later. We did not see a tendency to increased smoking among participants of the intervention arm or the entire study. The decline of smoking prevalence among the attendees of the counseling might be due to self-selection. Since the issue of effectiveness of smoking cessation counseling is important, further research with randomization into offering counseling or no intervention should be taken into consideration.