Cited by 826Statistical Methods in EpidemiologyAdvanced Causal Inference TechniquesCOVID-19 Clinical Research Studies

Collider bias undermines our understanding of COVID-19 disease risk and severity

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Griffith, Gareth J., Morris, Tim T., Tudball, Matthew J., Herbert, Annie, Mancano, Giulia, Pike, Lindsey, Sharp, Gemma C., Sterne, Jonathan +6 more·2020·Nature Communications

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Abstract

Numerous observational studies have attempted to identify risk factors for infection with SARS-CoV-2 and COVID-19 disease outcomes. Studies have used datasets sampled from patients admitted to hospital, people tested for active infection, or people who volunteered to participate. Here, we highlight the challenge of interpreting observational evidence from such non-representative samples. Collider bias can induce associations between two or more variables which affect the likelihood of an individual being sampled, distorting associations between these variables in the sample. Analysing UK Biobank data, compared to the wider cohort the participants tested for COVID-19 were highly selected for a range of genetic, behavioural, cardiovascular, demographic, and anthropometric traits. We discuss the mechanisms inducing these problems, and approaches that could help mitigate them. While collider bias should be explored in existing studies, the optimal way to mitigate the problem is to use appropriate sampling strategies at the study design stage.

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  1. [19]Nguyen, T. Q., Dafoe, A. & Ogburn E. L. The magnitude and direction of collider bias for binary variables. arXiv. http://arxiv.org/abs/1609.00606 (2016) · arXiv

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Authors
Griffith, G. J., Morris, T. T., Tudball, M. J., Herbert, A., Mancano, G., Pike, L., Sharp, G. C., Sterne, J., Palmer, T. M., Davey Smith, G., Tilling, K., Zuccolo, L., Davies, N. M., & Hemani, G.
Affiliations
  • University of Bristol (GB)
  • Norwegian University of Science and Technology (NO)
Corresponding author
Hemani, Gibran
Venue
Nature Communications
Published
2020-11-12
Volume
11
Issue
1
Pages
5749-5749
ISSN
2041-1723 (ISSN-L)
OpenAlex
W3093084901
Cited by
826
References
100
Citations by year
2026: 48 · 2025: 42 · 2024: 125 · 2023: 140 · 2022: 199 · 2021: 208 · 2020: 62 · 2019: 1
FWCI
106.77
Type
journal article
Language
en
Open access
Locations
  • Nature Communications (publishedVersion, cc-by)
  • medRxiv (acceptedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • Explore Bristol Research (acceptedVersion, cc-by)
  • RePEc: Research Papers in Economics (submittedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
  • Bristol Research (University of Bristol) (submittedVersion, cc-by)
Funders
Wellcome Trust (208806/Z/17/Z)
Topics
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Epidemiology
  • Physical Sciences › Mathematics › Statistics and Probability › Advanced Causal Inference Techniques
  • Health Sciences › Medicine › Infectious Diseases › COVID-19 Clinical Research Studies
Keywords
collider bias, COVID-19 pandemic, disease severity, non-representative samples, selection bias, UK Biobank, sampling strategy, observational study design
MeSH terms
Betacoronavirus, COVID-19, SARS-CoV-2, Humans, Pneumonia, Viral, Risk Factors, Bias, Treatment Outcome, Coronavirus Infections, Pandemics, Observational Studies as Topic

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