Question

Sample Design Literacy In “Cardiovascular Effects of Intravenous Triiodothyronine in Patients Undergoing Coronary Artery Bypass Graft Surgery” [Journal of the American Medical Association (JAMA), Vol. 275, No. 9], the authors explain that patients were assigned to one of three groups: (1) a group treated with triidothyronine, (2) a group treated with normal saline bolus and dopamine, and (3) a placebo group given normal saline. The authors summarize the sample design as “randomized and double-blind.” Describe the meaning of “randomized” and “double-blind” in the context of this study.

Short answer

Randomized means that the patients were assigned one of the three groups without following any pattern.

Double-blind implies that neither the patients nor the conductor of the experiment is aware of the treatment assigned to each of the patients.

Step-by-step solution

Given information

The three groups in the study:

(1) A group treated with triidothyronine

(2) A group treated with normal saline bolus and dopamine

(3) A placebo group administered normal saline

Step 2:Meaning of randomization and double-blind

Randomization means assigning the participants to a certain number of groups following a random process.

Also, an experiment is said to be double-blind if the treatments allocated to the subjects are unknown to the participants as well as the person conducting the experiment.

In the context of the experiment

In the study, the subjects are the patients of the study, and there are three groups of treatments.

When the patients are randomly assigned one of the three treatments, the experiment is said to be randomized.

Also, when the patients, as well as the person conducting the experiment, are unaware of the treatments being provided to the patients, the experiment is said to be double-blinded.