Smoking status in Danish lung cancer patients compared to the general population, 2005 - 2013

The Danish Health Authority (DHA) publishes the smoking status for the general Danish population every year. Smoking status is not recorded by the Danish Lung Cancer Registry (DLCR) - only tobacco consumption (pack years). To study the smoking status of lung cancer patients at the time of diagnosis we used DLCR to identify all patients from Funen (9% of the total Danish population) in the 9-year period 2005 to 2013. Patient charts were used to add information about smoking status to the existing information about pack years. For comparison, we calculated the expected smoking status for the patient group. Age and gender specific smoking status for the general Danish population in the same period (published at the DHA home page: www.sst.dk) was used. We defined subjects who had stopped smoking for one year or more as ex-smokers, while subjects abstinent for less than one year were defined as current smokers. It was possible to characterize the smoking status of 97.9% of the 3737 lung cancer patients in the analysis. Conclusion: The majority of Danish male and female lung cancer patients are current smokers at the time of diagnosis, but the fraction is declining as for the general population. The fraction of never-smokers was low for both male and female patients and did not change during the study period.