Health care resource utilization and costs of commercially insured US patients with atopic dermatitis switching from...

The recent expansion of US Food and Drug Administration-approved treatment options for moderate to severe atopic dermatitis (AD) has notably improved clinical management options. With the availability of these novel therapies, data on frequency of therapy switching and differences in health care resource utilization (HCRU) and costs between switchers and nonswitchers are limited.

To evaluate the frequency of treatment switching from first- to second-line systemic targeted therapies and compare HCRU and costs between switchers and nonswitchers among commercially insured US patients with moderate to severe AD.

We conducted a retrospective cohort study in which adult patients with AD initiating a first systemic targeted therapy (index date) between January 1, 2022, and December 31, 2022, were identified and followed for at least 1 year from index date. Two cohorts were classified based on whether switching occurred over follow-up. All-cause and AD-related HCRU oucomes, including hospitalizations, emergency department (ED) visits, and outpatient services, and associated costs were compared between switchers and nonswitchers during the follow-up period.

After approximately 1 year following the initiation of first-line systemic targeted therapy, 466 (5.8%) switched to second-line systemic targeted therapy among the 8,063 patients with moderate to severe AD included in this study. Nearly all switchers (96.4%) had at least 1 AD-related outpatient service compared with 82.8% for nonswitchers (P < 0.01), and the annualized rate of visits was higher among switchers compared with nonswitchers (4.9 vs 3.1, P < 0.01). AD-related hospitalizations and ED visits were rare. Mean total AD-related health care costs across the annualized follow-up period were also significantly higher among switchers compared with nonswitchers ($59,876 vs $51,327; P < 0.01), with drug costs accounting for approximately 99% of AD-related health care expenditures in both groups.

We found a small proportion (5.8%) of patients switched from first- to second-line systemic targeted therapy after a median follow-up of approximately one year. Patients who switched therapies incurred significantly higher AD-related outpatient service use and total health care costs compared with nonswitchers, which may potentially reflect either worsening disease severity or inadequate response or intolerability to first-line therapy. These findings emphasize the increased importance of personalized considerations for the selection of first-line systemic targeted therapy for patients with moderate to severe AD to reduce downstream economic burden. As additional therapies become available, future research exploring reasons for treatment switching and patient factors influencing response will be critical to guide clinical and formulary decision-making in this evolving treatment landscape.