Understanding Statistical Noise in Research: 2. Noise in Clinical Trials and Observational Studies

The previous article in this series explained basic concepts related to statistical signals and statistical noise in research. This article explains statistical noise in the context of randomized controlled trials (RCTs) and observational studies and offers suggestions on how noise in such studies may be reduced so as to better detect and understand the signal. Postrandomization bias related to RCTs and confounding in observational studies are discussed. Examples are provided to facilitate understanding.