RESULTS: Among a total of 2,140 subjects, five subgroups identified through k-means clustering include putative “near-normal (n=232)”, “asthmatic (n=392)”, “COPD (n=37)”, “asthma-overlap (n=893)” and “COPD-overlap (n=586)” subtypes. Near-normal subgroup showed the oldest mean age (72±7 years) and highest FEV1 (102±8% predicted), and asthmatic subgroup was the youngest (46±9 years). Asthma-overlap subgroup showed the lowest FEV1 (77±9% predicted). COPD and COPD-overlap subgroups were male-predominant (100% and 98%, respectively) and all current or ex-smokers. When applying the lower limit of normal FEV1/FVC as a criterion for airway obstruction, asthma group had the highest prevalence of airway obstruction. While COPD, asthma-overlap and COPD-overlap subgroups showed high prescription rate of respiratory medicine, asthmatic subgroup had the lowest prescription rate despite the highest proportion of self-reported wheezing. Except asthmatic subgroup, comorbidities such as hypertension, diabetes mellitus, hyperlipidemia and coronary artery disease were frequently observed. Any respiratory medication was prescribed for 365 subjects (17%) and the highest prescription rate was in COPD subgroup (24%); 2nd, asthma-overlap (22%); 3rd, COPD-overlap (17%). Although COPD subgroup represents only 2% of total subjects, they showed the highest mean medical cost and health utilization, comprising 5% of the total cost. When calculating a ratio of total medical expense to household income, mean ratio was the highest in COPD subgroup.