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