Non-inferiority trials: Determining whether alternative treatments are good enough

Scott, Ian A. (2009) Non-inferiority trials: Determining whether alternative treatments are good enough. Medical Journal of Australia, 190 6: 326-330.

Author Scott, Ian A.
Title Non-inferiority trials: Determining whether alternative treatments are good enough
Journal name Medical Journal of Australia   Check publisher's open access policy
ISSN 0025-729X
Publication date 2009-03-16
Sub-type Article (original research)
Volume 190
Issue 6
Start page 326
End page 330
Total pages 5
Place of publication Strawberry Hills, NSW, Australia
Publisher Australasian Medical Publishing Company
Language eng
Subject 1117 Public Health and Health Services
1103 Clinical Sciences
Formatted abstract
♦ New treatments that are potentially as effective as existing treatments are increasingly being developed, some of which may be preferred because of lower cost, fewer side effects, easier administration or less harm.

♦ Non-inferiority trials attempt to establish whether or not a new treatment — drug or non-drug — is no worse than an established treatment for which efficacy has been determined in placebo-controlled trials.

♦ Critical issues in the design and conduct of non-inferiority trials include:

  defining the acceptable margin of adverse events that, if exceeded, will render the new  treatment inferior to the standard treatment (the non-inferiority margin);
  calculating the sample size needed to demonstrate non-inferiority;
  assessing the robustness of results in terms of absolute versus relative effects, intention-to-treat versus per-protocol analyses, one-sided versus two-sided statistical tests, and observed versus expected event rates for standard treatment;
  evaluating all relevant outcomes, including harm; and
•  stating conclusions that are consistent with aims and results.

♦ Many non-inferiority trials fail to meet basic quality criteria, report biased and misleading conclusions, and are unduly influenced by commercial sponsors, with some commentators going so far as labelling them unethical.

♦ Clinicians and trial investigators need to exercise caution when interpreting results of non-inferiority trials which, because they lack a placebo group, can only provide an indirect assessment of the efficacy of a new treatment compared with an existing standard, and where the choice of non-inferiority margin can be highly subjective.
Keyword Alternative treatments
Non-inferiority trials
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
School of Medicine Publications
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Citation counts: TR Web of Science Citation Count  Cited 21 times in Thomson Reuters Web of Science Article | Citations
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Created: Thu, 03 Sep 2009, 08:01:42 EST by Mr Andrew Martlew on behalf of Faculty Of Health Sciences