Published Online: March 17, 2014. doi:10.1001/jamainternmed.2014.190.
Study concept and design: Both authors.
Acquisition of data: Oliver.
Analysis and interpretation of data: Both authors.
Drafting of the manuscript: Oliver.
Critical revision of the manuscript for important intellectual content: Both authors.
Statistical analysis: Both authors.
Obtained funding: Oliver.
Conflict of Interest Disclosures: None reported.