Not All Errors Are Created Equally: Biological Variability and Systematic Errors (Biases)

Errors can compromise the precision of observations, thereby detrimentally impacting diagnosis and treatment outcomes. Awareness of the primary types of bias and their implications is therefore critical, not only for individuals engaged in clinical research but also for clinicians interpreting the findings of clinical studies. This chapter outlines and examines the most significant biases in clinical research, offering insights valuable for critically appraising results from both interventional and diagnostic studies.