A review study on confounding effect

Abstract

Confounding is the distortion of a disease/exposure association brought about by other factors which are not considered in the study design or the data analvsis. These factors are culled continmdinL, factors. We should be cautious in data analvsis of observational study of association of disease/exposure, since confounding often occurred in observational study. This study examines confounding effect according to data pattern (the ratio of controls to cases, the ratio of exposures to non-exposures for each level of confounding factor), c6teda for treating a variable as a confounding variable. and some notes for the analysis in case-control study.