A counterfactual approach to bias and effect modification in terms of response types.

ABSTRACT:

Background

The counterfactual approach provides a clear and coherent framework to think about a variety of important concepts related to causation. Meanwhile, directed acyclic graphs have been used as causal diagrams in epidemiologic research to visually summarize hypothetical relations among variables of interest, providing a clear understanding of underlying causal structures of bias and effect modification. In this study, the authors aim to further clarify the concepts of bias (confounding bias and selection bias) and effect modification in the counterfactual framework.

Methods

The authors show how theoretical data frequencies can be described by using unobservable response types both in observational studies and in randomized controlled trials. By using the descriptions

SUBMITTER: Suzuki E 

PROVIDER: S-EPMC3765813 | biostudies-literature | 2013 Jul

REPOSITORIES: biostudies-literature