Airflow obstruction in never smokers in five Latin American cities: the PLATINO study

Background: Although chronic obstructive pulmonary disease (COPD) is mostly related to tobacco smoking, a variable proportion of COPD occurs in never smokers. We investigated differences between COPD in never smokers compared with smokers and subjects without COPD.

Methods: PLATINO is a cross-sectional population-based study of five Latin American cities. COPD was defined as postbronchodilator FEV(1)/FVC <0.70 and FEV(1) <80% of predicted values.

Results: Among 5,315 subjects studied, 2278 were never smokers and 3036 were ever smokers. COPD was observed in 3.5% of never smokers and in 7.5% of ever smokers. Never smokers with COPD were most likely older and reported a medical diagnosis of asthma or previous tuberculosis. Underdiagnosis was as common in obstructed patients who never smoked as in ever smokers.

Conclusions: Never smokers comprised 26% of all individuals with airflow obstruction. Obstruction was associated with female gender, older age and a diagnosis of asthma or tuberculosis.