05-05-2015, 07:03 AM
Confounding is a distortion of the association between an
exposure and an outcome that occurs when the study groups differ
with respect to other factors that influence the outcome
Effect modification is distinct from confounding; it occurs when
the magnitude of the effect of the primary exposure on an
outcome (i.e., the association) differs depending on the level of a
third variable.
http://sphweb.bumc.bu.edu/otlt/MPH-Modul...print.html
exposure and an outcome that occurs when the study groups differ
with respect to other factors that influence the outcome
Effect modification is distinct from confounding; it occurs when
the magnitude of the effect of the primary exposure on an
outcome (i.e., the association) differs depending on the level of a
third variable.
http://sphweb.bumc.bu.edu/otlt/MPH-Modul...print.html