Accepted for Publication: December 16, 2013.
Published Online: February 10, 2014. doi:10.1001/jamaneurol.2013.6222.
Study concept and design: Shulman, Bennett, De Jager.
Acquisition of data: Shulman, Buchman, Evans, Schneider, Bennett, De Jager.
Analysis and interpretation of data: Shulman, Yu, Buchman, Bennett, De Jager.
Drafting of the manuscript: Shulman, De Jager.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Shulman, Yu, De Jager.
Obtained funding: Buchman, Evans, Bennett, De Jager.
Administrative, technical, or material support: Buchman, Evans, Schneider, Bennett.
Study supervision: Evans, Bennett, De Jager.
Conflict of Interest Disclosures: Dr Shulman consults for the Helis Medical Research Foundation. No other disclosures were reported.
Funding/Support: The study was supported by the National Institutes of Health grants K08AG034290, P30AG10161, R01AG15810, R01AG17917, R01AG30146, R01NS78009, R01AG036836, and C06RR029965; the Illinois Department of Public Health; the Parkinson’s Disease Foundation/Parkinson’s Study Group; the Caroline Weiss Law Fund for Research in Molecular Medicine; and a Burroughs Wellcome Fund Career Award for Medical Scientists.
Role of the Sponsor: The sponsors 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 the participants in the MAP and ROS.