Author Contributions: Dr Schrag 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: Zhu, Sharma, Schrag.
Acquisition of data: Schrag.
Analysis and interpretation of data: Zhu, Sharma, Gray, Chen, Weeks, Schrag.
Drafting of the manuscript: Zhu, Schrag.
Critical revision of the manuscript for important intellectual content: Sharma, Gray, Chen, Weeks.
Statistical analysis: Zhu, Sharma.
Obtained funding: Weeks, Schrag.
Administrative, technical, or material support: Zhu, Sharma, Weeks, Schrag.
Study supervision: Zhu, Schrag.
Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Schrag reports receiving payment for American Society of Clinical Oncology educational talks. No other disclosures were reported.
Funding/Support: Project support was obtained from the National Cancer Institute (NCI) RC2CA148185-01 (to Dr Weeks). This project was also funded under contract HHSA290201000006I (to Dr Schrag) from the Agency for Healthcare Research and Quality (AHRQ) as part of the Developing Evidence to Inform Decisions about Effectiveness (DEcIDE) program. Dr Sharma was supported by NCI grant PO1-CA134294. The collection of the California cancer incidence data used in this study was supported by the California Department of Public Health as part of the statewide cancer reporting program mandated by California Health and Safety Code Section 103885; the NCI's SEER program under contract N01-PC-35136 awarded to the Northern California Cancer Center, contract N01-PC-35139 awarded to the University of Southern California, and contract N02-PC-15105 awarded to the Public Health Institute; and the Centers for Disease Control and Prevention's National Program of Cancer Registries under agreement U55/CCR921930-02 awarded to the Public Health Institute.
Role of the Sponsors: The funding agencies had no role in the design and conduct of the study; in the collection, management, analysis, and interpretation of the data; or in the preparation, review, or approval of the manuscript.
Disclaimer: The views expressed in this article are those of the authors and do not necessarily represent the views of the AHRQ, the NCI, or the Department of Health and Human Services. The ideas and opinions expressed herein are those of the authors and endorsement by the State of California, Department of Public Health, the NCI, and the Centers for Disease Control and Prevention or their contractors and subcontractors is not intended nor should be inferred.
Additional Contributions: We acknowledge support from Saul Weingart, MD, PhD, Center for Patient Safety, Dana-Farber Cancer Institute; Sebastian Schneeweiss, MD, ScD, Division of Pharmacoepidemiology, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School; and William Lawrence, MD, MS, Center for Outcomes and Evidence, AHRQ. No financial compensation was received. This study used the linked SEER-Medicare database. This resource has been made available to the research community through collaborative efforts of the NCI and CMS. We acknowledge the efforts of the Applied Research Program, NCI; the Office of Research, Development and Information, CMS; Information Management Services (IMS) Inc; and the SEER program tumor registries in the creation and ongoing maintenance of the SEER-Medicare database.