Healthcare utilization and costs of atopic dermatitis in Taiwan

Background: Atopic dermatitis (AD) is a common chronic skin disease. Only relatively scant studies from Asian countries have attempted to quantify AD-associated healthcare utilization and costs by using population-based databases. This study aims to evaluate the AD-associated annual healthcare utilization and costs in Taiwan. Methods: A retrospective matched-cohort study was conducted by matching the AD cases with controls at a 1:4 (cases:controls) ratio, with the data for both the cases and controls being sourced from the 2017 National Health Insurance Research Database (NHIRD). The AD patients were stratified by disease severity based on their treatments. Differences in the regression-adjusted frequency of care and costs between the cases and controls were compared using t-tests by the severity level of AD. Results: The incremental frequency of outpatient visits per year increased with AD severity (9.60, 11.28, and 16.23 for mild, moderate, and severe cases, respectively). However, the frequency of inpatient care and emergency room visits per year showed no consistent pattern associated with disease severity. The incremental total costs per year were NT$9,511.64, NT$9,705.20, and NT$15,762.09 for mild, moderate, and severe cases, respectively, and the outpatient and drug costs accounted for 46.65%–54.82% and 17.01%–31.20% of the total costs, respectively. Conclusion: AD was found to impose significant healthcare costs, with estimated total cost burdens of NT$3.61 billion in 2017, which is 0.314% of Taiwan's national health expenditure and 0.020% of Taiwan's gross domestic product.