Author Contributions: Dr Redelmeier 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: Redelmeier, Yarnell.
Acquisition of data: Redelmeier.
Analysis and interpretation of data: Redelmeier, Yarnell.
Drafting of the manuscript: Redelmeier, Yarnell.
Critical revision of the manuscript for important intellectual content: Redelmeier, Yarnell.
Statistical analysis: Redelmeier.
Obtained funding: Redelmeier.
Study supervision: Redelmeier.
Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.
Funding/Support: This project was supported by the Canada Research Chair in Medical Decision Sciences and the Canadian Institutes of Health Research.
Role of the Sponsors: The funding organizations 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: The views expressed are those of the authors and do not necessarily reflect those of the Ontario Ministry of Health.
Additional Contributions: We thank the following for helpful comments: Chaim Bell, MD, PhD, Michael Schull, MD, and John Staples, MD (all 3 with the University of Toronto, Toronto, Ontario, Canada), and Robert Tibshirani, PhD (Stanford University, Palo Alto, California). No compensation was provided to these individuals.