Randomized controlled trial

From RationalWiki

A randomized controlled trial (RCT) is a type of study that tries to evaluate a particular treatment or intervention, usually in a medical field. It is considered the most powerful type of medical evidence.

[edit] Randomization and Controls

In an RTC, randomization refers to how subjects are matched with the intervention. Let's say you wanted to know if giving patients with heart disease Pill X prevents further heart attacks. First, you would gather a group of people with heart disease, then randomly assign them to receive either the test substance (Pill X) or a control, preferably a placebo, or perhaps whatever pill is normally used. In this case, the study can also be double blind, in that neither the doctor nor the subject needs to know which pill a particular patient gets.

Then, the two groups can be watched over a particular period of time, and the number of heart attacks in each group calculated.

These statistics can then be used to calculate the effect of Pill X compared to placebo, and therefore the amount of good (or harm) Pill X can do in this situation.

Once results have been calculated, the effect of Pill X can be generalized to a population of patients similar to the sample of subjects in the study.

In this way, new treatments are evaluated and then implemented or rejected.