Randomized controlled trials (RCTs) are considered the gold standard for clinical research. An RCT involves randomly assigning participants into experimental and control groups to receive different interventions. Randomization aims to make the groups comparable to limit bias. It reduces the influence of unknown factors and ensures the only difference between groups is the intervention being tested. RCTs can be single blind, double blind, or triple blind depending on who is aware of group assignments. They provide the most powerful and least biased assessments of clinical interventions.

1. Randomized controlled trials The Basics

4. Schema of a simple trial Eligible patients Rx group 1 Rx group 2 Randomize

23. Analysis of clinical trials Analysis of clinical trials Intension to treat analysis Per protocol analysis Sub group analysis