[용어] Randomized controlled trial

자료 1. http://www.medicinenet.com/script/main/art.asp?articlekey=39532

Randomized controlled trial (RCT): A study in which people are allocated at random (by chance alone) to receive one of several clinical interventions. One of these interventions is the standard of comparison or control. The control may be a standard practice, a placebo ("sugar pill"), or no intervention at all. Someone who takes part in a randomized controlled trial (RCT) is called a participant or subject. RCTs seek to measure and compare the outcomes after the participants receive the interventions. 

In sum, RCTs are quantitative, comparative, controlled experiments in which investigators study two or more interventions in a series of individuals who receive them in random order. The RCT is one of the simplest and most powerful tools in clinical research.

자료 2. https://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0025811/

Randomized Control Trial (RCT). A study in which the participants are assigned by chance to separate groups; neither the researchers nor the participants can choose which group.

In the late 1940s, groups of researchers in Europe and the USA led one of the most important developments of modern medical science: they refined the methods for testing treatments in randomized controlled studies or "trials.""Randomized" means that volunteers are divided into groups by chance, like in a lottery. One of the groups then uses the treatment being tested. The experiences of the other group of people provide control or comparison data.

This makes it possible to see what effects the treatment actually has, and to make sure that the groups are not different from the start — for example, because one group has healthier people in it. This simple approach provides a way to find out if a treatment is effective, useless or even harmful.

자료 3. https://en.wikipedia.org/wiki/Randomized_controlled_trial

A randomized controlled trial (or randomized control trial. RCT) is a type of scientific (often medical) experiment which aims to reduce bias when testing a new treatment. The people participating in the trial are randomly allocated to either the group receiving the treatment under investigation or to a group receiving standard treatment(or placebo treatment) as the control.

Randomization minimises selection bias and the different comparison groups allow the researchers to determine any effect of the treatment when compared with the no treatment (control) group, while other variables are kept constant. 

RCT is often considered the gold standard for a clinical trial. RCTs are often used to test the efficacy or effectiveness of various types of medical intervention and may provide information about adverse effects, such as drug reactions. Random assignment of intervention is done after subjects have been assessed for eligibility and recruited, but before the intervention to be studied begins. ( ... ... )