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Smoking is the main risk factor for Chronic Obstructive Pulmonary Disease (COPD), formerly known as lung emphysema or ‘chronic bronchitis’. Early detection of COPD and smoking cessation may result in significant health gain. In a thesis titled ‘Detection of COPD in smokers’ the results of 6 studies in middle-aged male smokers, conducted between 1998 and 2003 in IJsselstein, a town in the center of The Netherlands, are presented. At the baseline survey, among 702 male smokers, mean age 50 years, the prevalence of previously undetected COPD defined according to the GOLD criteria was high (30%). Smokers with undetected disease predominantly experienced mild airflow obstruction (87%). In multivariate regression analysis only age and cough were independently related to the presence of mild COPD. The ability of these determinants to discriminate subjects without COPD from those with mild COPD was relatively poor (ROC area 0.65). In 2003, 33 of 399 participants developed moderate COPD, i.e. a cumulative incidence of 8.3%. Notably, limitations of physical functioning measured by the MRC dyspnoea scale correlated more strongly with quality of life than the COPD severity staging. The risk of developing moderate COPD in smokers with baseline mild COPD was 5 times higher than in those with baseline normal spirometry (1 in 5 vs. 1 in 25). Age, cough, smoking before the age of 16 years, and ? 1 recent GP consultations because of lower respiratory tract (LRT) complaints were independently associated with development of moderate COPD. A prediction rule, based on these 4 patients characteristics, showed a reasonable discriminative ability (ROC area 0.72). Taking a cut-off of ? 2 points would identify as much as 79% (26/33) of the smokers actually developing moderate COPD in the next 5 years and 52% of the smokers not developing moderate COPD. Among smokers 45-64 years of age, nationwide screening in The Netherlands was expected to offer approximately 195,000 newly detected cases with COPD in one year and case finding in general practice among smokers with respiratory tract complaints over 78,000 new cases. Screening however showed a less favorable balance of costs and effects than case finding. The cost-effectiveness of intensive smoking cessation therapy – costs per newly detected subject with COPD who remained abstinent during at least 1 year - was markedly more favorable than the cost-effectiveness of short smoking cessation therapy. Main recommendations: - Intensifying smoking cessation interventions targeted at smokers with a high risk of developing COPD (55-64 years of age, smoking before the age of 16 years, respiratory symptoms) and at smokers with physician diagnosed COPD, should be encouraged. - Screening for COPD in middle-aged smokers can not be recommended. Case finding seems an attractive alternative, provided that intensive smoking cessation therapy is logistically possible and drug treatment for nicotine addiction is reimbursed. - Health care resources should preferably be applied to facilitate additional measures to prevent uptake of smoking or encourage smoking cessation in the population at large rather than to develop COPD screening programs in ‘healthy’ smokers. |
