Author Contributions: Drs Mitchell and Shaffer had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Mitchell, Miller, Teno, Davis, Shaffer.
Acquisition of data: Mitchell.
Analysis and interpretation of data: Mitchell, Miller, Teno, Kiely, Davis, Shaffer.
Drafting of the manuscript: Mitchell, Kiely, Shaffer.
Critical revision of the manuscript for important intellectual content: Mitchell, Miller, Teno, Davis, Shaffer.
Statistical analysis: Mitchell, Teno, Kiely, Davis, Shaffer.
Obtained funding: Mitchell.
Administrative, technical, or material support: Mitchell, Miller, Shaffer.
Study supervision: Mitchell.
Financial Disclosures: None reported.
Funding/Support: This research was supported by the National Institutes of Health–National Institute on Aging (NIH-NIA) grant R01 AG028423. Dr Mitchell is supported by the NIH-NIA grant K24AG033640.
Role of the Sponsors: The funding sources for this study played no role in the design or conduct of the study, in the collection, management, analysis, and interpretation of the data, or in the preparation, review, or approval of the manuscript.