Cited by 285Advanced Causal Inference TechniquesMeta-analysis and systematic reviewsStatistical Methods in Clinical Trials

Biases in Randomized Trials: A Conversation Between Trialists and Epidemiologists

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Mansournia, Mohammad Ali, Higgins, Julian P. T., Sterne, Jonathan A. C., Hernán, Miguel A.·2017·Epidemiology

Abstract

Trialists and epidemiologists often employ different terminology to refer to biases in randomized trials and observational studies, even though many biases have a similar structure in both types of study. We use causal diagrams to represent the structure of biases, as described by Cochrane for randomized trials, and provide a translation to the usual epidemiologic terms of confounding, selection bias, and measurement bias. This structural approach clarifies that an explicit description of the inferential goal-the intention-to-treat effect or the per-protocol effect-is necessary to assess risk of bias in the estimates. Being aware of each other's terminologies will enhance communication between trialists and epidemiologists when considering key concepts and methods for causal inference.

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  • We label the domains using descriptions of the causes of bias addressed, avoiding terms used in the original RoB tool (such as 'selection bias' and 'performance bias') because they are used inconsistently or not known by many people outside Cochrane.

    “We label the domains using descriptions of the causes of bias addressed, avoiding terms used in the original RoB tool (such as 'selection bias' and 'performance bias') because they are used inconsistently or not known by many people outside Cochrane. 16”

    From RoB 2: a revised tool for assessing risk of bias in randomised trials (2019) · cites this paper as [16]

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  1. [4]Higgins JPT Green S Cochrane Handbook for Systematic Reviews of Interventions Chichester John Wiley & Sons 2008
  2. [6]Rothman KJ Greenland S Lash TL Validity in epidemiologic studies Rothman KJ Greenland S Lash T Modern Epidemiology 3rd Philadelphia, PA Lippincott Williams &Wilkins 2008 128 147
  3. [7]Miettinen OS Theoretical epidemiology New York Wiley 1985
  4. [8]Pearl J Causality 2nd New York Cambridge University Press 2009
  5. [18]Rosenberger WF Lachin JM Randomization in Clinical Trials: Theory and Practice New York Wiley 2002
  6. [21]Friedman LM Furberg CD DeMets DL Fundamentals of Clinical Trials 4th New York Springer 2010
  7. [23]Greenland S O'Rourke K Meta-analysis Rothman KJ Greenland S Lash T Modern Epidemiology 3rd Philadelphia, PA Lippincott Williams & Wilkins 2008 652 682
  8. [24]Steyerberg EW Clinical prediction models: a practical approach to development, validation, and updating New York, NY Springer 2008
  9. [27]Greenland S Rothman KJ Fundamentals of epidemiologic data analysis Rothman KJ Greenland S Lash T Modern Epidemiology 3rd Philadelphia, PA Lippincott Williams & Wilkins 2008 213 237

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Authors
Mansournia, M. A., Higgins, J. P. T., Sterne, J. A. C., & Hernán, M. A.
Affiliations
Harvard University (US)
Venue
Epidemiology
Published
2017-01
Volume
28
Issue
1
Pages
54-59
ISSN
1044-3983 (ISSN-L)
OpenAlex
W2336975416
Cited by
285
References
25
Citations by year
2026: 18 · 2025: 30 · 2024: 30 · 2023: 29 · 2022: 40 · 2021: 39 · 2020: 42 · 2019: 29 · 2018: 17 · 2017: 9 · 2016: 2
FWCI
19.21
Type
journal article
Language
en
Open access
Locations
  • Epidemiology (publishedVersion)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
  • Bristol Research (University of Bristol) (acceptedVersion, other-oa)
  • Explore Bristol Research (submittedVersion, other-oa)
Funders
  • National Institute for Health and Care Research (NF-SI-0611-10168, NF-SI-0616-10111)
  • Medical Research Council (MR/M025209/1, MR/K025643/1)
  • National Cancer Institute (P01CA134294, R35CA197449)
  • National Institute of Allergy and Infectious Diseases (R01AI102634)
Topics
  • Physical Sciences › Mathematics › Statistics and Probability › Advanced Causal Inference Techniques
  • Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Clinical Trials
Keywords
confounding, selection bias, measurement bias, causal graphs, intention-to-treat effect, risk of bias, terminology translation, causal inference
MeSH terms
Humans, Patient Dropouts, Observer Variation, Bias, Selection Bias, Causality, Confounding Factors, Epidemiologic, Randomized Controlled Trials as Topic, Intention to Treat Analysis

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