Chaicharn Pothirat, Warawut Chaiwong, Nittaya Phetsuk, Sangnual Pisalthanapuna, Nonglak Chetsadaphan, Juthamas Inchai

COPD prevalence and consequent burden are expected to rapidly increase worldwide. Until now, there has been no community-based study of COPD in Thailand. We aimed to compare the prevalence, clinical characteristics, disease severity, previous diagnosis, and management of COPD between urban and rural communities. A population-based cross-sectional study was designed to compare COPD prevalence and burden in rural and urban communities in Chiang Mai Province, Thailand. The COPD subjects were diagnosed and severity categories assigned using Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. The prevalence between the groups was compared using risk regression analysis. Unpaired t-test and chi-square were used to compare differences between the groups. There were 574 and 293 enrolled subjects with acceptable spirometry, in rural and urban communities respectively. The prevalence of COPD in general and COPD in females was higher in the rural group (6.8% vs 3.7% and 4.4% vs 0.9%, respectively) across all independent variables. However, after adjustment for age, sex, and smoking status, no significant differences were demonstrated. Although the pulmonary function and disease severity between the two groups were not significantly different, the tendency was more pronounced in the rural group (COPD stage III-IV: 65.0% vs 33.3%). Most of the COPD patients in both groups were underdiagnosed (80.0% vs 77.2%) and undertreated (85.0% vs 81.9%). None of the patients in the study had participated in exercise training programs. The prevalence of COPD in general and particularly COPD in females tended to be higher, with more severe disease in the rural community. However, both groups were similarly underdiagnosed and undertreated.