Author Contributions: Dr Kahn 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: Kahn, Carson, Iwashyna.
Acquisition of data: Kahn, Iwashyna.
Analysis and interpretation of data: Kahn, Benson, Appleby, Carson, Iwashyna.
Drafting of the manuscript: Kahn.
Critical revision of the manuscript for important intellectual content: Kahn, Benson, Appleby, Carson, Iwashyna.
Statistical analysis: Kahn, Benson, Appleby, Iwashyna.
Obtained funding: Kahn, Carson.
Administrative, technical, or material support: Kahn, Benson.
Financial Disclosures: None reported.
Funding/Support: This work was funded by grant R01HL096651 from the National Institutes of Health (NIH) (Dr Kahn). Dr Iwashyna is supported by NIH grant K08HL091249. This project was also funded, in part, under a grant from the Pennsylvania Department of Health, which specifically disclaims responsibility for any analyses, interpretations, or conclusions.
Role of the Sponsors: The funding agencies 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.
Additional Contributions: We thank Maximilian Herlim, BS, and Daohang Sha, PhD, for programming support, and Thomas R. Ten Have, PhD, for biostatistical support, all of the University of Pennsylvania, none of whom received compensation beyond their normal salaries.