Burden of obstructive lung disease in a rural setting in the Philippines.

Background and objective:  The aim of this study was to determine the prevalence of and risk factors associated with COPD in a rural setting in the Philippines. Methods:  The study was conducted in two municipalities in Nueva Ecija province in the Philippines. Using the Burden of Obstructive Lung Disease (BOLD) protocol and study design, non-hospitalized men or women, aged 40 years or older, were recruited by multi-stage random sampling procedures. Participants completed questionnaires on respiratory symptoms and exposure to potential risk factors for COPD, including smoking, occupation and exposure to burning of biomass fuel. Spirometry was performed according to American Thoracic Society criteria. Results:  Of the 1188 individuals selected for recruitment, 722 had acceptable post-bronchodilator spirometry and were classified according to Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage. The overall prevalence of COPD for all stages was 20.8%. The prevalence of COPD at GOLD Stage I or higher was greater in men compared with women (26.5% vs 15.3%), and increased between the ages of 40 to >70 years. Logistic regression analysis showed a significant association between all stages of COPD and farming for >40 years (odds ratio (OR) 2.48, 95% confidence interval (CI): 1.43–4.30), use of firewood for cooking for >60 years (OR 3.48, 95% CI: 1.57–7.71), a smoking history of ≥20 pack-years (OR 2.86; 95% CI: 1.78–4.60), and a history of tuberculosis (OR 6.31, 95% CI: 2.67–15.0). Conclusions:  The prevalence COPD in a rural community in Nueva Ecija, Philippines was 20.8% for GOLD Stage I or higher, and 16.7% for GOLD Stage II or higher. In addition to smoking history, the use of firewood for cooking, working on a farm and a history of tuberculosis were significantly associated with fixed airflow obstruction, as assessed by spirometry.