Hepatitis C virus infection as a risk factor for Parkinson disease: A nationwide cohort studyAuthor Response

Tsai et al.1 reported an association between hepatitis C virus (HCV) infection and Parkinson disease (PD) in their study of nearly 50,000 patients with HCV, hepatitis B virus (HBV), or HCV/HBV coinfection from the Taiwan National Health Insurance Research Database (2000–2010). Another recent and comparably large study found a similar association between PD and HCV infection.2 Both studies lacked an analysis of the association between treatment of …