OBJECTIVE The prevalence of asthma is increasing, and asthma causes considerable socioeconomic burden worldwide. Few studies have been conducted to evaluate the risk factors associated with economic cost of asthma in Korea. This study evaluated asthma cost according to severity, control, and patient factors in Korean tertiary hospitals.

METHODS Direct and indirect costs were assessed in physician-diagnosed adult asthmatics recruited from eight tertiary hospitals in Korea. Official direct medical costs were derived from the analysis of 1-year expenditures related to hospital care utilization and asthma medication. Nonofficial medical costs, nonmedical direct costs, and indirect costs were investigated using a questionnaire designed specifically for the study.

RESULTS A total of 314 patients with persistent asthma were recruited. Both direct and indirect costs were significantly higher for patients with severe persistent asthma than for those with mild and moderate persistent asthma ($2214 vs. $871 and $978, p < .001; $2927 vs. $490 and $443, p < .001, respectively). Costs of asthma increased significantly in poorly controlled compared with somewhat controlled and well-controlled asthma ($7009.8 vs. $2725.3 vs. $1517.3, respectively; p < .001). After stratification for severity, a significant cost increase in the poorly controlled asthma group was observed only for indirect costs and not for direct costs. A multivariate analysis showed that female gender was a risk factor for increased indirect costs.

CONCLUSION The burden of asthma was higher both for patients with severe persistent asthma and for patients with poorly controlled asthma. More effective strategies are needed to improve control status, particularly targeting patients with severe asthma.