Published Online: October 14, 2013. doi:10.1001/jamainternmed.2013.10399.
Study concept and design: All authors.
Acquisition of data: Sullivan, O’Donoghue.
Analysis and interpretation of data: Sullivan, O’Donoghue.
Drafting of the manuscript: Sullivan.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Sullivan, O’Donoghue.
Administrative, technical, or material support: O’Donoghue, Aikin.
Study supervision: Aikin.
Conflict of Interest Disclosures: None reported.
Additional Contribution: Adam Rosenblatt, MA, of Penn Schoen Berland assisted with data collection. Mr Rosenblatt received compensation for his work through a contract with the Food and Drug Administration.