The Prevalence of Parkinson Disease Among Patients With Hepatitis C Infection.

INTRODUCTION: HCV has been suspected to potentially cause degenerations in the central nervous system. Parkinson's disease is the second most common neurodegenerative disorder. Our aim was to assess the prevalence of Parkinson's disease among patients with HCV infection.

MATERIAL AND METHODS: For this study, we used Medicare database from 2005-2010. Medicare database contains information on enrollment, coverage, diagnosis recorded with International Classification of Disease, Ninth Revision (ICD-9). From combined inpatient and outpatient files, Parkinson's disease was identified as the first diagnosis by ICD-9 code 332.0. Other study variables were; age, gender, race (White and No White), and Medicare eligibility status. Simple distribution comparison by HCV status examined with t-test for numerical variables and ?2 test for categorical variables in the main analytical cohort as well as in the propensity score matched cohort.

RESULTS: A total of 1,236,734 patients (median age 76 years, 41% male, and 85% White) was identified among over 47 million claims. Of these, 6040 patients (0.5%) were infected with HCV. Overall, 0.8% (N = 49) of the HCV group and 1.3% (N = 16,004) of the Non-HCV group had Parkinson's disease (P < 0.001). When the study groups matched for age, gender and race, the prevalence of Parkinson's disease was similar between HCV and Non-HCV groups (P > 0.05).

DISCUSSION: This study revealed that, among Medicare population, HCV was not associated with Parkinson disease.