Author Contributions: Dr Kesselheim 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: Kesselheim, Avorn.
Acquisition of data: Kesselheim, Myers.
Analysis and interpretation of data: Kesselheim, Myers, Avorn.
Drafting of the manuscript: Kesselheim, Myers.
Critical revision of the manuscript for important intellectual content: Kesselheim, Avorn.
Statistical analysis: Myers.
Obtained funding: Kesselheim.
Study supervision: Avorn.
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: Dr Kesselheim is supported by career development award K08HS18465-01 from the Agency for Healthcare Research and Quality and a Robert Wood Johnson Foundation Investigator Award in Health Policy Research.
Role of the Sponsor: The sponsors 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 Deborah Schrag, MD, MPH, Department of Medical Oncology, Steven Joffe, MD, MPH, Department of Pediatric Oncology, and James E. Bradner, MD, Department of Medical Oncology, all from Dana-Farber Cancer Institute, Boston, Massachusetts, for their comments on a previous draft. They received no compensation for their work.