Accepted for Publication: April 9, 2013.
Published Online: August 12, 2013. doi:10.1001/jamaneurol.2013.3484.
Acquisition of data: All authors.
Analysis and interpretation of data: All authors.
Drafting of the manuscript: All authors.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Muehlschlegel.
Obtained funding: Muehlschlegel, Singhal.
Study supervision: Singhal.
Conflict of Interest Disclosures: Dr Muehlschlegel has received financial research support from the American Heart Association (grant 09SDG2030022), the Worcester Research Foundation (2010), and the University of Massachusetts Medical School (Faculty Scholar Award 2011). Dr Singhal has served as a medical expert witness in cases of stroke. Over the last 4 years, Dr Singhal has received research support from the National Institutes of Health/National Institute of Neurological Disorders and Stroke (grants R01NS051412, 1R21NS077442, 5R01NS38477, R21NS061119, R01NS059775, P01 NS035611, P50NS051343, and P50NS044148). He has served as consultant to Biogen Idec and reports grant support to his institution from Pfizer and Photothera. His wife, Priya Singhal, MD, MPH, is an employee of Biogen Idec. No other disclosures are reported.
Funding/Support: This work was funded in part by the American Heart Association (grant 09SDG2030022 to Dr Muehlschlegel), the Worcester Research Foundation, and the University of Massachusetts Medical School (Faculty Scholar Award to Dr Muehlschlegel).
Additional Contributions: We thank Bruce Barton, PhD, research professor at the Department of Quantitative Health Sciences, Division of Biostatistics and Health Services Research, University of Massachusetts Medical School, Worcester, for his advice and guidance in the statistical analysis plan.