Prevalence of COPD in Five Colombian Cities Situated at Low, Medium, and High Altitude (PREPOCOL Study)

Background The prevalence of COPD in Colombia is unknown. This study aimed to investigate COPD prevalence in five Colombian cities and measure the association between COPD and altitude. Methods A cross-sectional design and a random, multistage, cluster-sampling strategy were used to provide representative samples of adults aged ≥ 40 years. Each participant was interviewed (validated Spanish version of the Ferris Respiratory Questionnaire) and performed spirometry before and after 200 μg of inhaled salbutamol, using a portable spirometer according to American Thoracic Society recommendations. COPD definitions were as follows: (1) spirometric: fixed ratio (primary definition): FEV1/FVC < 70% after bronchodilator; (2) medical: a diagnosis of chronic bronchitis, emphysema, or COPD made by a physician; (3) clinical: cough and phlegm ≥ 3 months every year during ≥ 2 consecutive years (chronic bronchitis). Analysis was performed using statistical software. Results A total of 5,539 subjects were included. The overall COPD prevalence using the primary definition (spirometric) was 8.9%, ranging from 6.2% in Barranquilla to 13.5% in Medellín. The prevalence measured by the spirometric definition was higher than medical (2.8%) and clinical (3.2%) definitions. After the logistic regression analysis, the factors related with COPD were age ≥ 60 years, male gender, history of tuberculosis, smoking, wood smoke exposure ≥ 10 years, and very low education level. There was a nonsignificant tendency toward larger prevalence with higher altitude. Conclusion COPD is an important health burden in Colombia. Additional studies are needed to establish the real influence of altitude on COPD prevalence. The prevalence of COPD in Colombia is unknown. This study aimed to investigate COPD prevalence in five Colombian cities and measure the association between COPD and altitude. A cross-sectional design and a random, multistage, cluster-sampling strategy were used to provide representative samples of adults aged ≥ 40 years. Each participant was interviewed (validated Spanish version of the Ferris Respiratory Questionnaire) and performed spirometry before and after 200 μg of inhaled salbutamol, using a portable spirometer according to American Thoracic Society recommendations. COPD definitions were as follows: (1) spirometric: fixed ratio (primary definition): FEV1/FVC < 70% after bronchodilator; (2) medical: a diagnosis of chronic bronchitis, emphysema, or COPD made by a physician; (3) clinical: cough and phlegm ≥ 3 months every year during ≥ 2 consecutive years (chronic bronchitis). Analysis was performed using statistical software. A total of 5,539 subjects were included. The overall COPD prevalence using the primary definition (spirometric) was 8.9%, ranging from 6.2% in Barranquilla to 13.5% in Medellín. The prevalence measured by the spirometric definition was higher than medical (2.8%) and clinical (3.2%) definitions. After the logistic regression analysis, the factors related with COPD were age ≥ 60 years, male gender, history of tuberculosis, smoking, wood smoke exposure ≥ 10 years, and very low education level. There was a nonsignificant tendency toward larger prevalence with higher altitude. COPD is an important health burden in Colombia. Additional studies are needed to establish the real influence of altitude on COPD prevalence.