OBJECTIVES: Atopic dermatitis (AD) is a recurrent chronic skin disorder. AD generates a large economic burden on patients due to high costs of phototherapy and systemic drug use such as immunosuppressants and biologics. The objective of this study was to analyze direct medical costs associated with AD in adult patients according to the degree of severity using Korean national health care claim database.

METHODS: We conducted an observational and retrospective study with patients aged from 20 to 64 who have AD (ICD-10, L20). We used a dataset between January 1, 2011 and December 31, 2013 from the Health Insurance Review and Assessment Service. We defined 2 degrees of AD severity (Mild [M] and Moderate to Severe [MS]) using treatment steps for AD. Following this definition, AD patients were stratified by patients’ severity change at first-year and second-year period after the first diagnosed day. Using this concept, we evaluated the difference of direct medical cost at first and second-period in each cohort.

RESULTS: We included 2,129 adult AD patients (mean age: 36.5; female: 56.98%). We categorized the patients into 4 groups; M-M (n=1,333), M-MS (n=198), MS-M (n=245), and MS-MS (n=353). For the first-year, the median direct cost per patient in each group was US $28.00, $27.61, $51.67, and $63.45 respectively. The cost incurred during the second-year was US $19.21, $41.99, $23.83, and $43.95 respectively. The cost differences between the two follow-up periods in each group was statistically significant (Wilcoxon tests, p<0.001). The first-year cost of all patient is larger than the second-year cost (US $33.71, $23.98, P<0.001).

CONCLUSIONS: In a real-world data from Korean national claim database, the direct medical costs for treating AD varied according to the disease severity. We suggest that earlier and more aggressive therapy could reduce the direct medical costs in treating AD.