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Cited by 25Statistical Methods in Clinical TrialsMeta-analysis and systematic reviewsStatistical Methods in Epidemiology

Are claims of equivalency in digestive diseases trials supported by the evidence?☆

Tinmouth, Jill M., Steele, Leah S., Tomlinson, George, Glazier, Richard H.·2004·Gastroenterology
DOI 10.1053/j.gastro.2004.03.005
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Abstract

Background & aims Traditionally, randomized controlled trials (RCTs) have attempted to show the superiority of one intervention over another. However, when effective treatment already exists, it is sometimes more useful to prove that an intervention is equivalent, or at least not inferior, to the standard of care. Our aim was to determine whether claims of equivalency in digestive diseases trials are supported by the evidence.Methods Medline was searched for RCTs published between 1989 and 2002 using the MeSH headings "exp therapeutic equivalency" and "exp digestive diseases" and the text words "equivalence," "equal," "equals," or "equivalent," yielding 902 articles. Of these, 73 articles met the inclusion criteria. These articles were evaluated using previously published criteria for equivalency.Results Of the included articles, 33% stated an a priori research aim of equivalency, 92% reported differences of <20% between "equal" interventions, 34% set an equivalency boundary and tested it appropriately, and 19% performed a sample size calculation for equivalency. Overall, 12% of the reviewed articles met all 5 criteria. Fifty-two percent of our sample inappropriately used a failed superiority test (i.e., a P value > 0.05) as statistical "proof" of equivalency. Nonsurgical trials and those published between 1996 and 2002 were more likely to meet criteria than were surgical trials (P = 0.07) or trials published before 1996 (P = 0.003).Conclusions Claims of equivalency between interventions in digestive diseases trials tend to be poorly supported by the evidence. Erroneous claims of equivalency are potentially dangerous and may lead to substandard patient care.

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  • The interpretation of trial results in published reports is not always consistent with the prespecified conceptual framework.

    “In addition, the interpretation of trial results in published reports is not always consistent with the prespecified conceptual framework,198 199 200 especially among reports claiming post hoc equivalence based on a failure to show superiority, rather than on a specific test of equivalence.198”

    From SPIRIT 2025 explanation and elaboration: updated guideline for protocols of randomised trials (2025) · cites this paper as [199]

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Authors
Tinmouth, J. M., Steele, L. S., Tomlinson, G., & Glazier, R. H.
Affiliations
  • St. Michael's Hospital (CA)
  • Toronto General Hospital (CA)
Corresponding author
Tinmouth, Jill M.
ORCID
Venue
Gastroenterology
Publisher
Elsevier BV
Published
2004-06
Volume
126
Issue
7
Pages
1700-1710
ISSN
0016-5085 (ISSN-L)
DOI
10.1053/j.gastro.2004.03.005
OpenAlex
W2119239501
Cited by
25
References
87
Citations by year
2025: 1 · 2016: 3 · 2015: 1 · 2013: 1
FWCI
3.71
Type
journal article
Language
en
Open access
closed
Licence
www.elsevier.com/tdm/userlicense/1.0/ (tdm)
Locations
  • Gastroenterology (publishedVersion)
  • PubMed (publishedVersion)
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 › Statistical Methods in Epidemiology
Keywords
equivalence trials, gastrointestinal diseases, randomized controlled trials, statistical power, sample size determination
MeSH terms
Digestive System Diseases, Humans, Randomized Controlled Trials as Topic, Evidence-Based Medicine

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