OBJECTIVE: To estimate the incidence, prevalence, patient characteristics and healthcare utilization patterns of moderate to severe thyroid eye disease (TED) in the United States. DESIGN: Retrospective review of medical and prescription claims data from the Inovalon deidentified claims database. PATIENTS: Patients with moderate to severe TED were identified based on specific and sensitive definitions using International Classification of Diseases (ICD) codes selected by a group of TED specialists. RESULTS: The incident moderate to severe TED population included 3364 and 1730 patients using the sensitive and specific definitions, respectively. After adjusting for age and gender, corresponding incidence rates in the sensitive and specific populations were 8.97 (13.49 in women and 4.27 in men) and 4.37 (6.59 in women and 2.05 in men) per 100,000 person-years, respectively. The prevalent population included 16,310 and 8018 patients using the sensitive and specific definitions, respectively, corresponding to adjusted prevalence rates of 44.13 (66.00 in women and 21.39 in men) and 20.55 (31.18 in women and 9.50 in men) per 100,000 persons. A preponderance of women was observed, and comorbidity rates were high, with >
40% of prevalent patients experiencing hypertension. Steroids were the most frequently prescribed medication. The impact of teprotumumab was not captured, since this study only included claims data through 2019. CONCLUSIONS: The estimated incidence and prevalence rates of TED demonstrate the considerable impact of this disease in the United States, making the creation of a specific ICD code imperative for effective healthcare planning and management.