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Collider Bias

Educational Objective
To identify the key insights or developments described in this article
1 Credit CME

Bias is a systematic, nonrandom error in the estimation of a treatment effect or the effect of an exposure or risk factor. Bias can lead to invalid results in observational studies and randomized clinical trials (RCTs). Bias is often broadly categorized into 3 groups: confounding, information (or measurement) bias, and selection bias.1,2 Selection bias is a general term describing bias that occurs when study participants are identified in a manner such that they are no longer representative of the target population. This can occur when an exposure and outcome each influence a common third variable—the collider—and that variable has been controlled for in the statistical analysis of the study data.3 Collider bias threatens the internal validity of a study and the accurate estimation of causal relationships.

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CME Disclosure Statement: Unless noted, all individuals in control of content reported no relevant financial relationships. If applicable, all relevant financial relationships have been mitigated.

Article Information

Corresponding Author: Lars W. Andersen, MD, MPH, PhD, DMSc, Research Center for Emergency Medicine, Aarhus University Hospital, Palle Juul-Jensens Blvd 161, 8200, Aarhus, Denmark (lwandersen@clin.au.dk).

Published Online: March 14, 2022. doi:10.1001/jama.2022.1820

Conflict of Interest Disclosures: Dr Anderson serves as a statistical reviewer for JAMA. No other disclosures were reported.

References
1.
Rothman  J , Greenland  S , Lash  T.   Modern Epidemiology. 3rd ed. Lippincott Williams & Wilkins; 2008.
2.
Hernán  M , Robins  J .  Causal Inference: What If. Chapman & Hall/CRC; 2020.
3.
Hernán  MA , Hernández-Díaz  S , Robins  JM .  A structural approach to selection bias.   Epidemiology. 2004;15(5):615-625. doi:10.1097/01.ede.0000135174.63482.43PubMedGoogle ScholarCrossref
4.
Fosbøl  EL , Butt  JH , Østergaard  L ,  et al.  Association of angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use with COVID-19 diagnosis and mortality.   JAMA. 2020;324(2):168-177. doi:10.1001/jama.2020.11301PubMedGoogle ScholarCrossref
5.
Lipsky  AM , Greenland  S .  Directed acyclic graphs.   JAMA. 2022;327(11):1083-1084. doi:10.1001/jama.2022.1816Google ScholarCrossref
6.
Valls-Pedret  C , Sala-Vila  A , Serra-Mir  M ,  et al.  Mediterranean diet and age-related cognitive decline: a randomized clinical trial.   JAMA Intern Med. 2015;175(7):1094-1103. doi:10.1001/jamainternmed.2015.1668PubMedGoogle ScholarCrossref
7.
Shrier  I , Platt  RW .  Reducing bias through directed acyclic graphs.   BMC Med Res Methodol. 2008;8:70. doi:10.1186/1471-2288-8-70PubMedGoogle ScholarCrossref
8.
Griffith  GJ , Morris  TT , Tudball  MJ ,  et al.  Collider bias undermines our understanding of COVID-19 disease risk and severity.   Nat Commun. 2020;11(1):5749. doi:10.1038/s41467-020-19478-2PubMedGoogle ScholarCrossref
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