Accepted for Publication: January 2, 2015.
Published Online: March 23, 2015. doi:10.1001/jamaneurol.2015.8.
Study concept and design: Jung, Kim, Jeon, Paek.
Acquisition, analysis, or interpretation of data: Jung, Kim, Jeon, Park, Lee.
Drafting of the manuscript: Jung, Jeon.
Critical revision of the manuscript for important intellectual content: Kim, Jeon, Park, Lee, Paek.
Statistical analysis: Jeon.
Obtained funding: Jeon.
Administrative, technical, or material support: Jung, Jeon, Lee.
Study supervision: Jeon, Paek.
Conflict of Interest Disclosures: None reported.
Funding/Support: This study was supported by grant A101273 from the Korea Health Technology R&D Project, Ministry of Health & Welfare, Republic of Korea.
Role of the Funder/Sponsor: The funding source had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and the decision to submit the manuscript for publication.