Confounding is a major concern in epidemiology. Despite its significance, the different notions of confounding have not been fully appreciated in the literature, leading to confusion of causal concepts in epidemiology. In this article, we aim to highlight the importance of differentiating between the subtly different notions of confounding from the perspective of counterfactual reasoning. By us...

The field of epidemiology has seen many parameters enter the arena as risk factors. Many of them left the scene without leaving a mark, which was often caused by chance findings caused by small sample sizes or spurious associations resulting from confounding by other risk factors. Others became firmly established as risk factors, and therefore drug targets, but finally were dethroned by exclusi...

In 1986 the International Journal of Epidemiology published "Identifiability, Exchangeability and Epidemiological Confounding". We review the article from the perspective of a quarter century after it was first drafted and relate it to subsequent developments on confounding, ignorability, and collapsibility.

In social epidemiology, an individual’s neighborhood is considered to be an important determinant of health behaviors, mediators, and outcomes. Consequently, when investigating health disparities, researchers may wish to adjust for confounding byunmeasured neighborhood factors, such as local availability of health facilities or cultural predispositions. Withasimple randomsampleandabinaryoutcome...

In this issue, Lin et a!. ( 1) show convincing statistics that subjects exposed to dietary broccoli who have a GSTM 12 null phenotype are less susceptible to colon cancer than those who are GSTMI positive. The expected effect of a GSTM1 null phenotype is greater, not less, susceptibility to cancers due to reduced carcinogen detoxification by GSTM1 (2, 3). Broccoli reverses this outcome for two ...