Randomised controlled trials

Randomised controlled trials (RCTs) are a type of planned experiments with the aim of reliably comparing the outcomes of two interventions or changes in a group of people. They can be clinical trials, in which case the assessment is done on human beings with the purpose of testing a form of health care action such as drug administration, surgery, health education etc.

Characteristics of a clinical RCT

The groups of a clinical RCT

The RCT experiments involve allocating each member of the study's cohort to two different groups: the control group and the intervention group.

The intervention/experimental group will receive the intervention upon which questions have been raised. These can range from vaccines, drugs, surgeries to alternative/complementary medicine practices such as acupuncture and homoeopathy.

The control group will be the individuals who will either receive a placebo or the best practice at the time. The importance of this group is vital as it's presence accounts for producing results against which data from the intervention group will be compared.

It is worth to be noted that the experimental group can also be administered the current best practice as well as the new intervention, while the control can only be administered the current best practice. This approach is appropriate for determining if additional actions improve the best current practice outcomes.

Allocations to the two groups

Allocations to the two groups are ideally made in a randomised manner.

Randomisation is vital because it ensures that, before any treatment, patient groups are similar with regard to prognostic factors, both known and unknown.

Randomised allocation can be done through envelope drawing. The envelopes contain the group allocation for each trial participant. The options in the envelopes are independently generated by a person or a computer.