Risk Factors Associated with Chronic Obstructive Pulmonary Disease: a Comparison Between Urban and Rural Populations in Chengdu

Objective To determine risk factors associated with the prevalence of chronic obstructive pulmonary disease (COPD) in urban and rural populations in Chengdu. Methods A multistage random cluster sampling method was adopted to select participants from four communities in Chengdu. All residents aged 40-70 yr. were eligible to participate in this study, which involved a questionnaire survey, physical examination and portable spirometry. Those with airflow limitations were also given post-bronchodilator testing 15 min after inhalation of a dose of 200 μg salbutamol. We defined a forced expiratory volume in one second/forced vital capacity (FEV1/FVC) of less than 70% as COPD. Logistic regression models were performed to identify risk factors of COPD. Results Of a total of 1 931 eligible participants, 1 579 (81.77%) completed the questionnaire and spirometry. About 8.35% were identified with COPD: 7.69% in urban vs. 12.37% in rural (\P\P\P\P<0.05）. The multivariate analysis showed that tobacco smoking index (pack-year), education, age and BMI were predictors of COPD for male patients; whereas, coal fuel usage, income and BMI were predictors of COPD for female patients. Conclusion COPD prevalence is higher in rural areas than in urban Chengdu. Major risk factors of COPD include smoking, coal fuels and BMI.