Wilson disease in the USA: epidemiology and real-world patient characteristics based on a retrospective observational health claims study.

Objectives: To describe the epidemiology, patient characteristics and comorbidities in patients with Wilson disease (WD) in the USA.

Design: Retrospective, population-based study.

Setting: The study used the US Komodo claims database containing records regarding medical claims for over 120 million individuals.

Participants: Patients with WD were identified via ICD-10 (10th revision of the International Classification of Diseases) code during the study period 2016-2019 and no age restriction was applied. A further stratification by disease subtype ('hepatic', 'neurologic' and 'psychiatric') was performed.

Main Outcome Measures: WD prevalence was reported by age, sex and US census regions/divisions. Adjusted prevalence was calculated using age-specific prevalence standardised to the USA (2010 US census) and to the world (WHO 2000-2025) to enable comparisons across countries, using direct standardisation of prevalence estimates by age group.

Results: Overall, 2115 patients with WD were identified during the study period. Among them, 56.8% had hepatic symptoms, 57.0% neurologic symptoms and 47.4% psychiatric symptoms. The most frequent manifestations in hepatic patients were liver signs and symptoms (90.8%), in neurologic patients cognitive defects (50.7%) and in psychiatric patients mood disorders (86.4%). The mean age in the overall cohort was 39.9 years. Prevalence estimation was based on 1481 patients with WD between 2017 and 2019. The 2017-2019 crude period prevalence was 21.2 patients per million (95% CI: 20.1 to 22.3), with similar prevalence observed for both sexes.

Conclusions: This study provides important real-world data on the diagnosed prevalence of WD in the USA and revealed the comorbidities associated with various disease subtypes, thereby providing a comprehensive basis for guiding physicians and policy makers in the management of this chronic disease.