Cited by 264Meta-analysis and systematic reviewsStatistical Methods in Clinical TrialsPharmaceutical industry and healthcare

Turning a blind eye: the success of blinding reported in a random sample of randomised, placebo controlled trials

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Fergusson, D.·2004·BMJ

Abstract

OBJECTIVE: To examine the reporting and success of double blinding in a sample of randomised, placebo controlled trials from leading general medicine and psychiatry journals. METHODS: Identification of placebo controlled, randomised controlled trials from prespecified general medical and psychiatric journals indexed on Medline between 1 January 1998 and 1 October 2001, from which a random sample of 200 randomised clinical trials was chosen, of which 191 trials were evaluated. RESULTS: Only seven of the 97 (7%) general medicine trials provided evidence on the success of blinding, with five reporting that the success of blinding was imperfect. In trials from psychiatric journals, the success of blinding was reported in eight of the 94 trials, with four reporting that the blinding was imperfect. Overall, only four of the 191 (2%) trials assessed blinding in the participants and either the outcome assessors or the investigators. CONCLUSIONS: The current lack of reporting on the success of blinding provides little evidence that success of blinding is maintained in placebo controlled trials. Trialists and editors should make a concerted effort to incorporate, report, and publish such information and its potential effect on study results.

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Crossref · 10.1136/bmj.37952.631667.ee

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Authors
Fergusson, D.
Corresponding author
Fergusson, D.
Venue
BMJ
Publisher
BMJ
Published
2004-02-21
Volume
328
Issue
7437
Pages
432-0
ISSN
  • 0007-1447 (ISSN-L)
  • 0959-8138
  • 1468-5833
OpenAlex
W2138919074
Cited by
264
References
23
Citations by year
2026: 3 · 2025: 11 · 2024: 10 · 2023: 9 · 2022: 15 · 2021: 14 · 2020: 9 · 2019: 7 · 2018: 15 · 2017: 6 · 2016: 8 · 2015: 8 · 2014: 6 · 2013: 13 · 2012: 15
FWCI
21.67
Type
journal article
Language
en
Open access
Locations
  • BMJ (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • HighWire Press Open Archive (submittedVersion)
  • DigitalGeorgetown (Georgetown University Library) (submittedVersion)
Topics
  • Social Sciences › Decision Sciences › Statistics, Probability and Uncertainty › Meta-analysis and systematic reviews
  • Physical Sciences › Mathematics › Statistics and Probability › Statistical Methods in Clinical Trials
  • Life Sciences › Pharmacology, Toxicology and Pharmaceutics › Pharmacology › Pharmaceutical industry and healthcare
Keywords
blinding, double blinding, randomized controlled trials, trial reporting quality, general medicine journals, psychiatric journals
MeSH terms
Double-Blind Method, Randomized Controlled Trials as Topic

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