Quantification of Bias in Direct Effects Estimates Due to Different Types of Measurement Error in the Mediator

Assessing whether the effect of exposure on an outcome is completely mediated by a third variable is often done by conditioning on the intermediate variable. However, when an association remains, it is not always clear how this should be interpreted. It may be explained by a causal direct effect of the exposure on the disease, or the adjustment may have been distorted due to various reasons, such as error in the measured mediator or unknown...