Epidemiology of Wilson disease in Germany - real-world insights from a claims data study.

Background: Wilson disease (WD) is a rare disorder of copper metabolism, causing copper accumulation mainly in the liver and the brain. The prevalence of WD was previously estimated around 20 to 33.3 patients per million for the United States, Europe, and Asia, but data on the prevalence of WD in Germany are limited.

Objectives: To describe patient characteristics and to assess prevalence of WD in Germany using a representative claims database.

Methods: WD patients were identified in the WIG2 (Wissenschaftliches Institut für Gesundheitsökonomie und Gesundheitssystemforschung; Scientific Institute for Health Economics and Health Systems Research) benchmark database of 4.5 million insured Germans by combining ICD-10-coding with WD-specific lab tests and treatments. The study period ranged from 2013 to 2016 for assessing patient characteristics, and to 2018 for prevalence, respectively.

Results: Seventy unique patients were identified. Most patients (86%) were between 18 and 64 years of age and more often male (60%) than female. Two patients (3%) younger than 18 years were included, as well as 8 patients (11%) older than 64 years. Most common WD subtypes were hepatic (57%), psychiatric (49%), and neurologic (44%). Average prevalence was 20.3 patients per million (range: 17.8-24.4), with similar results for two-year prevalence. Generally, prevalence increased steadily over the study period. Observed mortality was low, with only one death during the study period.

Conclusions: This study adds valuable real-world data on the prevalence and patient characteristics of WD in Germany. Generally, our findings align with other reports and contribute to the global understanding of WD epidemiology. Still, regional and temporal trends remain to be investigated more thoroughly to further the understanding of the natural history and epidemiology of this rare disease.