Accepted for Publication: March 17, 2015.
Published Online: May 26, 2015. doi:10.1001/jamaneurol.2015.0654.
Study concept and design: Hwang, Kwon.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: Hwang.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Hwang, S. J. Park.
Obtained funding: Hwang.
Administrative, technical, or material support: Huh, Lee, Villavicencio, Villamor, Ahn, Kim, Chang, S. J. Park, N.-M. Park, Jeong.
Study supervision: Hwang, Kwon.
Conflict of Interest Disclosures: None reported.
Funding/Support: This study was supported by grant HI10C2020 from the Korea Healthcare Technology R&D Project, Ministry of Health and Welfare, Republic of Korea.
Role of the Funder/Sponsor: The funder 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 decision to submit the manuscript for publication.
Additional Contributions: We thank all participants for their contributions. They did not receive financial compensation.