Study concept and design: McNulty.
Acquisition of data: Hung, Almers.
Analysis and interpretation of data: McNulty, Hung, Go, Yeh.
Drafting of the manuscript: McNulty.
Critical revision of the manuscript for important intellectual content: McNulty, Hung, Almers, Go, Yeh.
Statistical analysis: McNulty, Hung, Almers.
Obtained funding: McNulty.
Administrative, technical, and material support: McNulty.
Study supervision: McNulty, Yeh.
Conflict of Interest Disclosures: The authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Go reported receiving research grant support from Genentech. Dr Yeh reported receiving consulting fees from Kaiser Permanente Northern California Division of Research. No other disclosures were reported.
Funding/Support: This study was supported by a grant from the Kaiser Permanente Northern California Community Benefits Program.
Role of the Sponsors: Kaiser Permanente had no role in the design and conduct of the study; the collection, management, and analysis, and interpretation of the data; the preparation, review or approval of the manuscript; or the decision to submit the manuscript for publication.
Additional Contributions: We thank Ralph Brindis, MD (University of California, San Francisco, School of Medicine), Matthew Solomon, MD, PhD (Kaiser Permanente Oakland Medical Center), and John Spertus, MD, for critical, uncompensated review of the manuscript.