Abstract
BACKGROUND: There are limited real-world analyses of patients with hypereosinophilic syndrome (HES) in the United States. OBJECTIVE: To describe and compare treatment patterns and disease burden between patients with diagnosed or predicted HES and those without HES with elevated blood eosinophil count (BEC). METHODS: Open claims data were used to identify patients with 2 or more BECs greater than 1000 cells/μL, who were classified into 3 cohorts: patients with an HES diagnosis code (group 1), patients identified as having HES by a claims-based prediction model (group 2), and patients without HES with elevated BEC (group 3). HES-related treatments, disease manifestations, HES flares, and all-cause health care resource utilization were evaluated during the 12 months following a randomly selected elevated BEC. Group 3 was compared with groups 2 and 1, separately, using Wilcoxon rank-sum test for continuous variables and χ(2) test for categorical variables. RESULTS: The study included 212 patients in group 1, 8089 in group 2, and 132,945 in group 3. Approximately 62.3% of group 1 patients received 1 or more HES-related treatment, with corticosteroids being the most common (59.0%). The most common disease manifestations were those related to the upper airway/pulmonary (61.8%), constitutional (46.2%), dermatologic (35.8%), and gastrointestinal systems (34.4%). Among patients in group 1, 22.2%, 97.2%, and 25.9% had 1 or more inpatient, outpatient, and emergency department visit, respectively. Compared with group 3, groups 1 and 2 had more corticosteroid use and health care resource utilization (all P < .05). CONCLUSIONS: Patients with HES had a substantial clinical and health care resource utilization burden versus those without HES with elevated BEC.