What is Collider Bias and Why Should We Care?

Abstract

Bias can threaten any study's internal validity compromising the findings. Bias is a nonrandom error that may affect the relationship between an exposure, risk factor, or treatment and the outcome. Bias can arise at any point in the research process, be it in the early stages of sample selection or the final stages of result rationalization and publication. There are 3 main types of bias: selection bias, information bias, and confounding bias.1