Objective: To ascertain the differences in smoking
characteristics between a group of smokers with COPD and another group
of healthy smokers, both of which were identified in a population-based
Design and participants: This is
an epidemiologic, multicenter, population-based study conducted in
seven areas of Spain. A total of 4,035 individuals, men and women aged
40 to 69 years, who were selected randomly from a target population of
236,412 subjects, participated in the study.
Interventions: Eligible subjects answered the European
Commission for Steel and Coal questionnaire. Spirometry was performed
followed by a bronchodilator test when bronchial obstruction was
present. The Fagerström questionnaire was used for study of the
degree of physical nicotine dependence, and the Prochazka model was
followed for analysis of the smoking cessation phase.
Results: Of 1,023 active smokers, 153 (15%) met
the criteria for COPD. Smokers with COPD were more frequently men (odds
ratio [OR], 2.18; 95% confidence interval [CI], 1.21 to 3.95),
were ≥ 46 years of age (OR, 1.97; 95% CI, 1.18 to 3.31), had a lower
educational level (OR, 1.96; 95% CI, 1.23 to 3.14), and had smoked>
30 pack-years (OR, 3.70; 95% CI, 2.42 to 5.65). Smokers with COPD
showed a higher dependence on nicotine than healthy smokers (mean[±
SD] Fagerström test score, 4.77 ± 2.45 vs
3.15 ± 2.38, respectively; p < 0.001) and higher concentrations
of CO in exhaled air (mean concentration, 19.7 ± 16.3 vs
15.4 ± 12.1 ppm, respectively; p < 0.0001).
Thirty-four percent of smokers with COPD and 38.5% of smokers without
COPD had never tried to stop smoking.
Smokers with COPD have higher tobacco consumption, higher dependence on
nicotine, and higher concentrations of CO in exhaled air, suggesting a
different pattern of cigarette smoking. Cases of COPD among smokers
predominate in men and in individuals with lower educational levels. A
significant proportion of smokers have never tried to stop smoking;
thus, advice on cessation should be reinforced in both groups of