Author Contributions: Dr Maggard-Gibbons 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. All data used for this study are accessible for review.
Study concept and design: Maggard-Gibbons, Maglione, Maher, Hu, Li, Shekelle.
Acquisition of data: Maggard-Gibbons, Livhits, Ewing, Maher, Hu.
Analysis and interpretation of data: Maggard-Gibbons, Maglione, Livhits, Ewing, Maher, Li, Shekelle.
Drafting of the manuscript: Maggard-Gibbons, Livhits, Ewing, Maher, Hu, Shekelle.
Critical revision of the manuscript for important intellectual content: Maglione, Maher, Li, Shekelle.
Statistical analysis: Maggard-Gibbons, Livhits, Ewing, Maher, Hu, Li.
Obtained funding: Maglione, Shekelle.
Administrative, technical, or material support: Maglione, Shekelle.
Study supervision: Maglione, Li, Shekelle.
Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Maggard-Gibbons reports receiving grant support from the Agency for Healthcare Research and Quality (AHRQ). Ms Maglione reports receiving grant support from AHRQ. Dr Hu reports receiving grant support from AHRQ. Dr Li reports receiving grant support from AHRQ. Dr Shekelle reports consulting for Emergency Care Research Institute, being employed at VA Health Services, and receiving grant support from AHRQ, VA Health Services, Centers for Medicare & Medicaid Services, National Institutes of Health, and Office of the National Coordinator and royalties from UpToDate.
Funding/Support: This project was funded under the contract 290-2007-10062I from the AHRQ and US Department of Health and Human Services.
Role of the Sponsor: The AHRQ had input into the design and conduct of evidence reviews conducted by the Evidence-Based Practice Centers, but not this specific evidence review, and was not involved in the collection, management, or analyses of the data, nor the decision to submit the manuscript for publication, but did review and provide comments on the evidence report upon which this article is based.
Disclaimer: The authors of this report are responsible for its content. Statements in the report should not be construed as endorsement by the AHRQ, US Department of Health and Human Services, and the Department of Veterans Affairs.
Additional Contributions: We thank Dr Dixon for the data on his trial. We also thank Roberta Shanman, MLS (Reference Services, RAND Library), who conducted the literature searches and Tanja Perry, BHM (Southern California Evidence-Based Practice Center, RAND Health), who contributed to the manuscript. Dr Dixon received no compensation for his contribution. All other contributors are regular staff of the Southern California Evidence-Based Practice Center.