A clinical study in which the participants are allocated randomly to receive an experimental clinical intervention (such as a new antibiotic) or a control intervention. RCTs are considered the most rigorous test of efficacy of a new treatment.
The control intervention may be a placebo or the usually used treatment for a condition (standard of care).
Ideally, neither patient nor experimenter should know which treatment is being given (a double-blind RCT). If it is not possible for the experimenter not to be aware of the treatment, a single-blind design is used.
In open-label trials, both patient and experimenter are aware which treatment is being provided. This creates a significant risk of bias. Various methods are used to reduce the risk of bias, such as assessment of outcomes by an individual who does not know which treatment was given.
Designing a research project: randomised controlled trials and their principles (Emergency Medicine Journal, 2003)
Randomized controlled trials – a matter of design (Neuropsychiatric Disease and Treatment, 2016)
Common statistical concerns in clinical trials (Journal of Experimental Stroke & Translational Medicine, 2010)
Statistical and methodological considerations for reporting RCTs in medical literature (Korean Journal of Anesthesiology, 2015)