Study concept and design: Neuman, Rosenbaum, Zubizarreta, Silber.
Acquisition, analysis, or interpretation of data: Neuman, Rosenbaum, Ludwig, Silber.
Drafting of the manuscript: Neuman, Rosenbaum.
Critical revision of the manuscript for important intellectual content: Neuman, Rosenbaum, Ludwig, Zubizarreta, Silber.
Statistical analysis: Neuman, Rosenbaum, Ludwig, Zubizarreta, Silber.
Obtained funding: Neuman.
Administrative, technical, or material support: Neuman.
Study supervision: Neuman.
Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.
Funding/Support: This study was supported by grants to MDN from the Foundation for Anesthesia Education and Research and 1K08AG043548 from the National Institute on Aging (Dr Neuman) and by grant 1260782 the from the National Science Foundation, (Dr Rosenbaum).
Role of the Sponsors: Sponsors had no role in the design or conduct of the study, the collection, management, analysis, or interpretation of data, the preparation, review, or approval of the manuscript, or the decision to submit the manuscript for publication.
Additional Contributions: Maps were created by Jolan Falk, BS, Creative Force, which was paid for his work.