Published Online: March 30, 2015. doi:10.1001/jamaneurol.2014.3739.
Study concept and design: Sahgal, Das.
Acquisition, analysis, or interpretation of data: All authors.
Drafting of the manuscript: Zarnett, Sahgal, Gosio, Das.
Critical revision of the manuscript for important intellectual content: Zarnett, Sahgal, Perry, Berger, Chang, Das.
Statistical analysis: Zarnett, Das.
Obtained funding: Das.
Study supervision: Zarnett, Sahgal, Chang, Das.
Conflict of Interest Disclosures: None reported.
Funding/Support: Dr Das is supported by the Canadian Cancer Society Research Institute. Mr Zarnett is supported by the Comprehensive Research Experience for Medical Students Award from the University of Toronto.
Role of the Funder/Sponsor: The funders 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: Kevin Thorpe, MMath, Applied Health Research Centre, Li Ka Shing Knowledge Institute, St Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada, reviewed the articles to determine the level of evidence accrued; he received no compensation.