Confounding in Observational Studies Explained
Bikaramjit Mann*, 1, Evan Wood2, 3
Identifiers and Pagination:Year: 2012
First Page: 18
Last Page: 20
Publisher Id: TOEPIJ-5-18
Article History:Received Date: 15/01/2012
Revision Received Date: 06/03/2012
Acceptance Date: 15/03/2012
Electronic publication date: 16/5/2012
Collection year: 2012
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: (https://creativecommons.org/licenses/by/4.0/legalcode). This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Practical and ethical constraints mean that many clinical and/or epidemiological questions cannot be answered through the implementation of a randomized controlled trial. Under these circumstances, observational studies are often required to assess relationships between certain exposures and disease outcomes. Unfortunately, observational studies are notoriously vulnerable to the effect of different types of “confounding,” a concept that is often a source of confusion among trainees, clinicians and users of health information. This article discusses the concept of confounding by way of examples and offers a simple guide for assessing the impact of is effects for learners of evidence-based medicine.