J. Mortensen

Chronic obstructive lung disease in Copenhagen: cross-sectional epidemiological aspects

Abstract Lange P, Groth, S, Nyboe J, Appleyard M, Mortensen J, Jensen G, Schnohr P (Copenhagen City Heart Study, Medical Department B and Department of Clinical Physiology and Nuclear Medicine KF, Rigshospitalet, and Medical Department P, Bispebjerg Hospital, Copenhagen, Denmark). Chronic obstructive lung disease in Copenhagen: cross‐sectional epidemiological aspects.

Phlegm production in plain cigarette smokers who changed to filter cigarettes or quitted smoking

Abstract. Data from a prospective epidemiological study that included 2025 plain cigarette smokers were analysed to investigate the effect on phlegm production of changing to filter cigarettes or quitting smoking. During a 5‐year follow‐up, 189 subjects quitted smoking, 312 changed to filter cigarettes, while 1524 continued to smoke plain cigarettes. Multiple logistic regression was used to adjust for age, duration of smoking, number of cigarettes smoked, socio‐economic status and alcohol consumption. Smokers with morning phlegm at enrolment, who changed to filter cigarettes during the follow‐up, had a probability ratio of 1.9 of phlegm production ceasing, compared with smokers who continued to smoke plain cigarettes (P < 0.05). However, the probability ratio of developing morning phlegm among smokers who changed to filter cigarettes compared to those who continued to smoke plain cigarettes was 1.6 (P < 0.05). The overall prevalence of morning phlegm at the end of the follow‐up was the same in smokers who changed to filter cigarettes as in persistent plain cigarette smokers. The trends for chronic phlegm were similar, although they did not reach statistical significance. The smokers who stopped smoking had a probability ratio of 0.4 of developing morning phlegm (P < 0.01) and a ratio of 7.7 for ceasing to produce it (P < 0.001) compared to the smokers who continued to smoke plain cigarettes. Our results suggest that changing from plain to filter cigarettes is associated with a higher frequency of cessation of phlegm production, but offers no protection against the development of phlegm.