Authors: Vikram R Comondore; P J Devereaux; Qi Zhou; Samuel B Stone; Jason W Busse; Nikila C Ravindran; Karen E Burns; Ted Haines; Bernadette Stringer; Deborah J Cook; Stephen D Walter; Terrence Sullivan; Otavio Berwanger; Mohit Bhandari; Sarfaraz Banglawala; John N Lavis; Brad Petrisor; Holger Schünemann; Katie Walsh; Neera Bhatnagar; Gordon H Guyatt Journal: BMJ Date: 2009-08-04