Epidemiology of Huntington's Disease in the United States Medicare and Medicaid Populations.

Introduction: Huntington's disease (HD) is a rare, genetic, and ultimately fatal neurodegenerative disease, with a devastating impact on individuals and families across generations. Few estimates of HD epidemiology in the United States (US) exist.

Methods: This study employed a retrospective cross-sectional design to examine the epidemiology of HD in the US Medicare and Medicaid beneficiary populations using 2016-2017 claims data from the Medicare 100% Research Identifiable Files (RIFs) and 2014 claims data from the Medicaid Analytic eXtract (MAX) files for 17 states. Medicare beneficiaries ≥65 years with a diagnosis of HD (≥1 claim with ICD-10-CM code G10) in 2017 and Medicaid beneficiaries <65 years with a diagnosis of HD (≥1 claim with ICD-9-CM code 333.4) in 2014 were identified. The study outcomes included the 2017 prevalence proportion and incidence rate of HD in the Medicare population and the 2014 prevalence proportion of HD in the Medicaid population.

Results: In the Medicare population, 1,941 prevalent and 819 incident cases of HD were identified in 2017, corresponding to a prevalence proportion of 13.1 per 100,000 persons and incidence rate of 6.1 per 100,000 person-years. In the Medicaid population, 353 prevalent cases of HD were identified in 2014, corresponding to a prevalence proportion of 15.2 per 100,000 persons.

Conclusion: This study suggests that prevalence and incidence of HD in the US may be higher than previously estimated. This has important implications in raising awareness of HD among providers and payers and ensuring availability of and access to services for HD patients and care partners in the Medicare and Medicaid populations.