Accepted for Publication: April 21, 2014.
Published Online: July 21, 2014. doi:10.1001/jamaneurol.2014.1279.
Study concept and design: Callaghan, Kerber, Lisabeth, Morgenstern, Longoria, Longwell, Feldman.
Acquisition, analysis, or interpretation of data: Callaghan, Kerber, Longoria, Rodgers, Longwell.
Drafting of the manuscript: Callaghan.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Callaghan, Kerber, Lisabeth, Rodgers.
Obtained funding: Morgenstern.
Administrative, technical, or material support: Longoria, Longwell.
Study supervision: Callaghan, Morgenstern, Feldman.
Conflict of Interest Disclosures: Dr Callaghan reported receiving research support from Impeto Medical and performing center certifications for the ALS Association. Dr Kerber reported receiving speaker honoraria from the American Academy of Neurology and Munson Medical Center and serving as a consultant for the American Academy of Neurology and The Weinberg Group. No other disclosures were reported.
Funding/Support: This study was funded by National Institutes of Health grant R01 NS38916.
Role of the Sponsor: 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 decision to submit the manuscript for publication.