Introduction to Epidemiology 6th Edition by Ray M Merrill

Exercise 10

Compare and contrast effect modification with confounding.

Step 1 of 4

Confounding is the destruction of the relationship between the cause or exposure and its outcome. This occurs when there are other variables that also affect the outcome, other than those variables which have been accounted for in a given study. This type of bias however, can get adjusted or eliminated in the study analysis.

Effect modification is caused when the effect of a primary variable has an outcome that differs in magnitude when a third variable is put into picture. Thus under this, a certain variable can differentially modify the outcome of a primary variable.