Author Contributions: Dr Brauer 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: Brauer, Coca-Perraillon, Cutler, Rosen.
Acquisition of data: Coca-Perraillon, Cutler, Rosen.
Analysis and interpretation of data: Brauer, Coca-Perraillon, Cutler, Rosen.
Drafting of the manuscript: Brauer, Coca-Perraillon, Cutler, Rosen.
Critical revision of the manuscript for important intellectual content: Coca-Perraillon, Cutler, Rosen.
Statistical analysis: Coca-Perraillon, Cutler.
Obtained funding: Cutler, Rosen.
Administrative, technical, or material support: Cutler, Rosen.
Study supervision: Cutler, Rosen.
Financial Disclosures: None reported.
Funding/Support: This work was supported by unrestricted grants P01 AG31098, P30 AG12810, and P01AG005842 from the National Institute on Aging. Dr Brauer had unrestricted salary support from the Alberta Heritage Foundation for Medical Research. We also appreciate the support of the Harvard Interfaculty Program for Health Systems Improvement.
Role of the Sponsor: The supporters had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript.
Disclaimer: This research was performed at the National Bureau of Economic Research, Cambridge, Massachusetts.
Additional Contributions: We thank Douglas M. Norton, BA, a research assistant at the National Bureau of Economic Research, for help with the initial data analysis. He received no compensation for his help.