Disease definitions and treatment thresholds are often based on dichotomisation of continuous variables. Examples of these dilemmas are the definition of hypertension and the continuum of pathologies in polyps in colorectal cancer (CRC) screening. Continuous variables are a clinical dilemma since they make it difficult to determine when to diagnose and intervene. Dichotomisation requires per definition a threshold which results in an epidemiological dilemma: if the threshold is set too low, too many people are overdiagnosed and overtreated, whereas if the threshold is set too high, too many people are underdiagnosed and undertreated.
We will present empirical research on these dilemmas and then have a discussion on how to solve them. We will present research on the following dilemmas: