Clinical characteristics of COPD syndrome: A 6-year follow-up study of adult smokers

Abstract

Background. There is little quantitative information about the development of chronic obstructive pulmonary disease (COPD) among adult smokers and of what happens to patients who have already developed COPD.

Objectives. To examine the development and performance of COPD status over time, and the clinical characteristics of new COPD cases according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2007 and 2011 classifications.

Methods. Healthy asymptomatic smokers were recruited through newspaper announcements. They filled in questionnaires and had an individualized assessment of their health history during all three visits (visit 1, visit 2 after three years, visit 3 after six years).

Results. Of the eligible 621 heavy smokers, 572 attended visit 2. A total of 513 subjects completed the 6-year follow-up examination. According to GOLD 2007, COPD was present in 22.8% (n = 117) of these smokers. The severity of COPD changed during the years of follow-up. Furthermore, health status and prevalence of chronic respiratory symptoms both in the smokers with normal lung function and in the COPD groups varied over the time period.

Conclusions. GOLD 2011 recognized the complex patient subgroups better than GOLD 2007. Variability in chronic symptoms or in health status correlated poorly with the severity of airway limitation.

Key words: :

• Adult
• chronic obstructive pulmonary disease
• disease classification
• spirometry

Acknowledgements

We thank Ewen MacDonald for the linguistic revision of our manuscript and Mrs Maija-Liisa Tarkiainen for her secretarial assistance. We also acknowledge Professor Vuokko L. Kinnula (deceased 2012) for her valuable contribution to the design of this study.

Funding: This study was financially supported by a governmental subsidy from the Ministry of Social Affairs and Health (125/STA/TE/2006), a governmental subsidy for health science research (EVO) in Rovaniemi (86/23.4.2003). This study project received a clinical research grant via Lapland Central Hospital from the pharmaceutical company GlaxoSmithKline (CRT115378).

Declaration of interest: The authors report no conflicts of interest.