The DOI matches its Crossref record; 13 of the 13 references it cites were found in a registry or an index.
Bias in Treatment Assignment in Controlled Clinical Trials
Abstract
Controlled clinical trials of the treatment of acute myocardial infarction offer a unique opportunity for the study of the potential influence on outcome of bias in treatment assignment. A group of 145 papers was divided into those in which the randomization process was blinded (57 papers), those in which it may have been unblinded (45 papers), and those in which the controls were selected by a nonrandom process (43 papers). At least one prognostic variable was maldistributed (P less than 0.05) in 14.0 per cent of the blinded-randomization studies, in 26.7 per cent of the unblinded-randomization studies, and in 58.1 per cent of the nonrandomized studies. Differences in case-fatality rates between treatment and control groups (P less than 0.05) were found in 8.8 per cent of the blinded-randomization studies, 24.4 per cent of the unblinded-randomization studies, and 58.1 per cent of the nonrandomized studies. These data emphasize the importance of keeping those who recruit patients for clinical trials from suspecting which treatment will be assigned to the patient under consideration.
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“However, there is evidence that poor reporting of randomisation increases the odds of presenting 'significant' outcomes (Chalmers 1983;Schulz 1995).”
From Psychological therapies for people with borderline personality disorder. (2012) · cites this paper as Chalmers 1983
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“Using a validated method of randomisation helps minimise selection bias and reduce systematic differences in the characteristics of animals allocated to different groups [62–64].”
From Reporting animal research: Explanation and elaboration for the ARRIVE guidelines 2.0 (2020) · cites this paper as [64]
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Metadata
- Authors
- Chalmers, T. C., Celano, P., Sacks, H. S., & Smith, H.
- Affiliations
- Mount Sinai Hospital (US)
- Venue
- New England Journal of Medicine
- Publisher
- Massachusetts Medical Society
- Published
- 1983-12
- Volume
- 309
- Issue
- 22
- Pages
- 1358-1361
- ISSN
- 0028-4793 (ISSN-L)
- 1533-4406
- OpenAlex
- W2030192997
- Cited by
- 864
- References
- 13
- Citations by year
- 2026: 1 · 2025: 3 · 2024: 8 · 2023: 6 · 2022: 10 · 2021: 9 · 2020: 8 · 2019: 14 · 2018: 7 · 2017: 18 · 2016: 15 · 2015: 19 · 2014: 15 · 2013: 18 · 2012: 19
- FWCI
- 13.03
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- New England Journal of Medicine (publishedVersion)
- PubMed (publishedVersion)
- DigitalGeorgetown (Georgetown University Library) (submittedVersion)
- Topics
- Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Clinical Trials
- Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
- Physical Sciences › Mathematics › Statistics and Probability › Advanced Causal Inference Techniques
- Keywords
- unblinding, acute myocardial infarction, case fatality, control selection, clinical trial design
- MeSH terms
- Clinical Trials as Topic, Ethics, Medical, Humans, Myocardial Infarction, Outcome and Process Assessment, Health Care, Prognosis, Random Allocation, Research Design, Risk
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