Author Contributions: Dr Ascherio had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Levin, Ascherio.
Acquisition of data: Munger, Levin, Howard, Ascherio.
Analysis and interpretation of data: Munger, Levin, Hollis, Ascherio.
Drafting of the manuscript: Munger, Hollis, Ascherio.
Critical revision of the manuscript for important intellectual content: Munger, Levin, Hollis, Howard, Ascherio.
Statistical analysis: Munger, Ascherio.
Obtained funding: Munger, Levin, Ascherio.
Administrative, technical, or material support: Munger, Levin, Howard, Ascherio.
Study supervision: Howard, Ascherio.
Financial Disclosures: Dr Hollis is a consultant for Diasorin. No other disclosures were reported.
Funding/Support: This work was supported by grants NS46635 and NS042194 from the National Institute of Neurological Diseases and Stroke and by a pilot grant from the National Multiple Sclerosis Society.
Role of the Sponsors: The sponsors had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; or preparation, review, or approval of the manuscript.
Disclaimer: The views expressed are those of the authors and should not be construed to represent the positions of the Department of the Army, the Department of the Navy, or the Department of Defense.
Acknowledgment: We thank Mark Rubertone, MD, MPH, Army Medical Surveillance Activity, US Army Center for Health Promotion and Preventive Medicine, Washington, DC, and Remington Nevin, MD, MPH, US Army Medical Corps, Center for Biosurveillance, Army Medical Surveillance Activity, Washington, DC, for control and sample identification and retrieval; Charles Peck, Jr, MD, and David Armitage, MD, JD, US Army Physical Disability Agency, Washington, DC, for MS case identification in the US Army; Walter Willett, MD, MPH, DrPH, and Meir Stampfer, MD, DrPH, Departments of Nutrition and Epidemiology, Harvard School of Public Health, and Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Mass, for their valuable input, and Leslie Unger and Eilis O’Reilly, MSc, Department of Nutrition, Harvard School of Public Health, Boston, Mass, for technical assistance.