Author Contributions:Study concept and design: Cheung and Ginde. Acquisition of data: Cheung and Ginde. Analysis and interpretation of data: Cheung, Wiler, and Ginde. Drafting of the manuscript: Cheung. Critical revision of the manuscript for important intellectual content: Wiler and Ginde. Obtained funding: Cheung and Ginde. Administrative, technical, and material support: Ginde. Study supervision: Ginde.
Financial Disclosure: None reported.
Funding/Support: This study was supported by grants from the Emergency Medicine Foundation, Society for Academic Emergency Medicine, and Adler Scholarship.
Previous Presentation: An abstract of this study was presented at the Society for Academic Emergency Medicine Conference; June 5, 2011; Boston, Massachusetts.