Prevalence and characteristics of chronic obstructive pulmonary disease in non-smokers

Objective: The objective of the study was to know the profile of patients diagnosed with chronic obstructive pulmonary disease (COPD) and who have never been smokers. Design: A transversal study. Location: Primary Care Centre of Pla d'Urgell (Primary care setting in Lleida, Spain). Participants: 512 patients older than 40 years with COPD from Primary Care Centre of Pla d'Urgell with a compatible spirometry [forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) ratio <0.7) to the beginning of the study. Main measurements: The dependent variable was de COPD in non-smokers and the independents were variables collected from the information on the respiratory clinical history, the risk factors of the patients and on quality of life. We designed a predictor model of COPD in non-smokers compared to smokers. Results: 33.2% of COPD patients had never been smokers, 59.4% of whom were women. The average FEV1 for non-smokers was 70.5 (SD =17.1), higher than 62.6 (SD = 18.5) for smokers/former smokers (p < 0.001). The coverage of pneumococcal vaccination 23V was better in non-smokers (75.3%), p < 0.001. COPD in non-smokers (compared to smokers/former smokers) were: mostly women (OR= 16.46), older (OR= 1.1), with better FEV1 (OR= 1.1), better perception of quality, EuroQoL-5D (OR = 0.8), with lower prevalence of diabetes (OR = 0.5), lower level of studies (OR = 0.2), and with fewer previous hospitalizations (OR = 0.3). Conclusions: The study evidences a high proportion of non-smokers in COPD patients. Our study aims that older women with less severity would be associated with an increased risk of COPD in non-smokers. It seems to indicate that COPD in non-smokers would appear at later ages and would be milder than smoking-related COPD. (C) 2018 The Authors. Published by Elsevier Espana, S.L.U.