Causation, bias and confounding: a hitchhiker's guide to the epidemiological galaxy Part 2. Principles of causality in epidemiological research: confounding, effect modification and strength of association.

摘要

In Part 1 of this series the following principles of causation were considered: time order, specification of the study base, and specificity (bias due to random misclassification and bias due to systematic misclassification).1 Part 2 will consider: 2a: Confounding 2b: Effect modification 2c: Strength of association.Part 3 concludes the consideration of causal principles and will discuss statistical stability, dose- and duration-response effects, internal consistency, external consistency, analogy and biological plausibility.