Tools & Techniques Methodology and Statistics: Randomisation in clinical trials

Randomised controlled trials (RCTs) are the gold standard by which the efficacy and safety of diagnostic and therapeutic strategies are evaluated1. Randomisation means that trial participants have a predefined probability of assignment to one of the predefined allocation groups. The allocation should neither be predictable nor determined by the researcher, treating physician or participants. Randomisation results in valid estimates of treatment effect, as it minimises bias due to differential selection and confounding2. The quality of a RCT, however, also depends on another important aspect of RCTs, namely blinding. Blinding refers to study related procedures after randomisation and aims to keep ...