Prevalence of Chronic Obstructive Pulmonary Disease and Asthma in the Community of Pathumthani, Thailand

<b>Background</b>: Airway diseases, particularly asthma and chronic obstructive pulmonary disease (COPD), pose significant respiratory problems. The prevalence and risk factors of these diseases among community dwellers vary geographically and because of underdiagnosis. This study aims to determine the prevalence and factors associated with these diseases in a provincial-metropolitan area in Thailand. <b>Methods</b>: A cross-sectional study was conducted between April 2023 and November 2023 on individuals aged 18 years or older residing in Pathumthani, Thailand. Data on demographics, pre-existing diseases, respiratory symptoms, and pulmonary functions assessed by spirometry, including forced vital capacity (FVC), forced expiratory volume in one second (FEV₁), and bronchodilator responsiveness (BDR), were collected. COPD was defined as having respiratory symptoms, a risk factor, and post-bronchodilator FEV₁/FVC < 70%. Asthma was defined as having respiratory symptoms and a positive bronchodilator responsiveness. <b>Results</b>: A total of 1014 subjects (71.7% female) were included, with a mean age of 56.6 years. The smoking history was 10.4% (13.4 pack-years). Common symptoms included cough (18.4%), sputum production (14.5%), and dyspnea (10.0%). COPD was found in 8.3%, while asthma was found in 10.3%. Logistic regression analysis indicated that these diseases were significantly associated with older age (odds ratio [OR] 1.023; 95% confidence interval [CI] 1.007-1.039 for every 1-year increase in age), smoking (OR 2.247; 95% CI 1.068-4.728), heart disease (OR 2.709; 95% CI 1.250-5.873), wheezing (OR 3.128; 95% CI 1.109-8.824), runny nose (OR 1.911; 95% CI 1.050-3.477), and previous treatment for dyspnea (OR 6.749, 95% CI 3.670-12.409). <b>Conclusions</b>: COPD and asthma were relatively prevalent in our study. Being elderly, smoking, having heart disease, and experiencing any respiratory symptoms with a history of treatment are crucial indicators for these airway diseases. Pulmonary function testing might be needed for active surveillance to detect these respiratory diseases in the community.