The Epidemiology of Thyroid Eye Disease in Olmsted County, Minnesota, 2005–2020

<b><i>Objective:</i></b> To describe the epidemiology of thyroid eye disease (TED). <b><i>Methods:</i></b> A population-based cohort of all Olmsted County, Minnesota, residents who had newly diagnosed TED between January 1, 2005, and December 31, 2020, was identified through the medical diagnostic index of the Rochester Epidemiology Project. Individuals aged 18 years and older were included. Incidence rates and point prevalence were calculated. Baseline disease characteristics and progression of disease were described. <b><i>Results:</i></b> We identified 83 incident patients, of whom 75 (90.4%) were female. The overall age and sex adjusted incidence for the U.S. population were 5 cases/100,000 person-years. Females had higher incidence (8.9 cases/100,000 person-years) compared with men (1 case/100,000 person-years). The distribution of peak incidence rates by 5-year age groups differed between male and female, in which females had peak incidence rates in the age groups 60-64 years and 80-84 years (18.3 cases and 18 cases/100,000 person-years, respectively), while male had peak incidence rate in the age group 70-74 years (5.7 cases/100,000 person-years). No clear trend was identified for the yearly incidence between 2005 and 2020. The overall estimated point prevalence per 100,000 was 65 (CI, 53.3-78.7). Prevalence was 114.5 (CI, 92.6-139.9) for females and 13.8 (CI, 6.8-24.6) for males (<i>p</i> < 0.001). Factors associated with disease progression were severity of soft tissue involvement (hazard ratio [HR] 7.7; CI, 2-29.8) and presence of diplopia (HR 2.5, CI, 1.2-5.1). <b><i>Conclusions:</i></b> Incidence rates for TED remained stable over the past two decades, yet lower than that in the previous study from our population. Females continue to have the peak incidence rate a decade earlier than males, and the majority of disease burden is present after the age of 50 years. Appropriate resources should be devoted to furthering education, management, and research into this condition.