Published Online: June 17, 2013. doi:10.1001/jamainternmed.2013.6638.
Study concept and design: Messori.
Acquisition of data: All authors.
Analysis and interpretation of data: All authors.
Drafting of the manuscript: All authors.
Critical revision of the manuscript for important intellectual content: Fadda, Maratea, Trippoli.
Statistical analysis: All authors.
Conflict of Interest Disclosures: None reported.