Randomized Trial - A Type of Cohort Study
Lead Editor(s): Jeff Martin, MD
Randomized Trial
Difference Between Observational Cohort Study and Randomized Trial
- A randomized trial of whatever flavor (blinded, placebo-controlled, etc.) is a cohort study in which the exposure/treatment is determined by the investigators rather than just observed as in an observational cohort study.
Randomized Clinical Trial
Difficult to Control All Variables
- Even well-designed clinical trials, however, do not always achieve the experimental goal of completely controlling all variables influencing the outcome because individuals may change their treatment on their own, change other behaviors during the course of the study, or be lost to observation by the investigators.