title: Observational studies as alternatives to randomized clinical trials in surgical clinical research.
authors.affiliation: Clinical Epidemiology Group, Department of Surgery, University of Toronto, Ontario, Canada.
authors.forename: X
authors.initials: X
authors.lastname: Hu
authors.forename: J G
authors.initials: JG
authors.lastname: Wright
authors.forename: R S
authors.initials: RS
authors.lastname: McLeod
authors.forename: A
authors.initials: A
authors.lastname: Lossing
authors.forename: B C
authors.initials: BC
authors.lastname: Walters
mesh_terms: D016022:Case-Control Studies; D015331:Cohort Studies; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D013514:Surgical Procedures, Operative