What does the term 'randomized controlled trial' (RCT) refer to?

The term 'randomized controlled trial' (RCT) refers specifically to a study design that assigns participants randomly to different groups, typically including at least one experimental group that receives the intervention and a control group that does not. This random assignment is crucial because it helps to eliminate bias and ensures that the groups are comparable at the start of the trial. By controlling for variables that could affect the outcomes, RCTs provide a robust way to determine the effectiveness of an intervention or treatment.

In contrast, using a control group alone does not encompass the fundamental aspect of randomization that defines an RCT. Qualitative approaches focus on understanding phenomena through descriptive data rather than numerical outcomes and do not involve randomized trials. Observational studies, which do not involve intervention or random assignment, differ significantly from the rigorous methodology that characterizes RCTs. Overall, the random assignment in RCTs is what allows for strong causal inferences about the efficacy of interventions tested within the study.