Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.
aDepartment of Anesthesia and Perioperative Care, UCSF Medical Center at Mt Zion, San Francisco, CA, USA
bDepartment of Epidemiology and Biostatistics, UCSF Medical Center at Mt Zion, San Francisco, CA, USA
cInstitute of Anesthesiology and Outcomes Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
dDepartment of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
eDepartment of Pharmacology, Temple University School of Medicine, Philadelphia, PA, USA
fDepartment of Anaesthesiology, Ludwig-Maximilians-University, Munich, Germany
*Corresponding author. Address: Department of Epidemiology and Biostatistics, UCSF Medical Center at Mt Zion, 1600 Divisadero, C-447, San Francisco, CA 94115, USA. Tel.: +1 415 885 7842; fax: +1 415 885 7770.
E-mail address:[email protected]
Article history: Received 25 August 2012; Received in revised form 21 December 2012; Accepted 31 December 2012.
