Why all randomised controlled trials produce biased results

  title={Why all randomised controlled trials produce biased results},
  author={Alexander Krauss},
  journal={Annals of Medicine},
  pages={312 - 322}
  • A. Krauss
  • Published 4 April 2018
  • Economics
  • Annals of Medicine
Abstract Background: Randomised controlled trials (RCTs) are commonly viewed as the best research method to inform public health and social policy. Usually they are thought of as providing the most rigorous evidence of a treatment’s effectiveness without strong assumptions, biases and limitations. Objective: This is the first study to examine that hypothesis by assessing the 10 most cited RCT studies worldwide. Data sources: These 10 RCT studies with the highest number of citations in any… 

Assessing the Overall Validity of Randomised Controlled Trials

  • A. Krauss
  • Economics
    International Studies in the Philosophy of Science
  • 2021
ABSTRACT In the biomedical, behavioural and social sciences, the leading method used to estimate causal effects is commonly randomised controlled trials (RCTs) that are generally viewed as both the

Randomised controlled trials may have many unrecognised potential biases

Randomised controlled trials (RCTs) may be the gold standard, but all that glisters is not gold, warns a research fellow at the London School of Economics.1 Alexander Krauss has analysed the 10 most

Quantitative and Qualitative Strategies to Strengthen Internal Validity in Randomized Trials

  • S. SidaniH. O’Rourke
  • Psychology
    The Canadian journal of nursing research = Revue canadienne de recherche en sciences infirmieres
  • 2020
Although the randomized controlled trial (RCT) is the most reliable design to infer causality, evidence suggests that it is vulnerable to biases that weaken internal validity. In this paper, we

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  • N. Kabeer
  • Sociology
    Journal of Human Development and Capabilities
  • 2019
Abstract This paper sets out to synthesize key lessons from studies using alternative methodologies to impact assessment. Drawing on Sen’s capability approach as a conceptual framework, it analyses

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The distinction between legitimate versus illegitimate changes was elucidated to serve as a guide for less experienced clinical trialists and other stakeholders to provide assurance to all stakeholders of their validity.

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In April 2018, the Annals of Medicine published a provocative piece titled “Why all randomised controlled trials produce biased results” that ignores prior literature that explains and/or refutes several key points.

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Data recorded in primary care are a rich resource and linkage could provide near real-time information to supplement trials and an efficient and cost-effective mechanism for long-term follow-up, according to a set of recommendations on linkage and supplementation of trials.

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It is proposed that triangulation of RCTs and observational studies, merging multiple lines of evidence with different underlying bias structures, can build a strong argument for causality.

Funding of Clinical Trials and Reported Drug Efficacy∗

The effect of financial sponsorship on reported drug efficacy is estimated, leveraging the insight that the exact same sets of drugs are often compared in different randomized control trials conducted by parties with different financial interests.



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A RANDOMIZED controlled trial (RCT) is the most reliable method of assessing the efficacy of health care interventions.1,2Reports of RCTs should provide readers with adequate information about what

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There is strong evidence of an association between significant results and publication; studies that report positive or significant results are more likely to be published and outcomes that are statistically significant have higher odds of being fully reported.

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The view is widely held that experimental methods (randomised controlled trials) are the "gold standard" for evaluation and that observational methods have little or no value, but this ignores the limitations of randomised trials.

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Why There's No Cause to Randomize

  • J. Worrall
  • Philosophy
    The British Journal for the Philosophy of Science
  • 2007
The evidence from randomized controlled trials (RCTs) is widely regarded as supplying the ‘gold standard’ in medicine—we may sometimes have to settle for other forms of evidence, but this is always

Make journals report clinical trials properly

The Centre for Evidence-Based Medicine at the University of Oxford, UK, is targeting the problem of selective outcome reporting in clinical trials, showing that outcome-switching is highly prevalent, and that such switches often lead to more favourable statistically significant results being reported instead.

Are RCTs the Gold Standard?

To draw causal inferences about a target population, which method is best depends case-by-case on what background knowledge the authors have or can come to obtain, including the hypothetico-deductive method.

Pharmaceutical industry sponsorship and research outcome and quality: systematic review

Investigating whether funding of drug studies by the pharmaceutical industry is associated with outcomes that are favourable to the funder and whether the methods of trials funded by pharmaceutical companies differ from the methods in trials with other sources of support found systematic bias favours products which are made by the company funding the research.