Author Contributions: Dr Rosenthal 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: Rosenthal, Landon, Normand, Frank, Epstein.
Acquisition of data: Rosenthal, Landon, Ahmad, Epstein.
Analysis and interpretation of data: Rosenthal, Landon, Normand, Frank, Ahmad, Epstein.
Drafting of the manuscript: Rosenthal, Normand, Ahmad.
Critical revision of the manuscript for important intellectual content: Rosenthal, Landon, Normand, Frank, Ahmad, Epstein.
Statistical analysis: Rosenthal, Normand, Frank, Ahmad.
Obtained funding: Rosenthal, Normand, Frank, Epstein.
Administrative, technical, or material support: Ahmad, Epstein.
Study supervision: Rosenthal, Ahmad.
Financial Disclosures: None reported.
Funding/Support: Financial support for this project was provided by the Agency for Healthcare Research and Quality (R01 HS 13335).
Role of the Sponsor: The Agency for Healthcare Research and Quality 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.