StATS: Steps in a typical equivalence data analysis (November 27, 2003)

There are three approaches that are used to demonstrate equivalence, each with its advantages and disadvantages.

  1. Establish adequate power
  2. Report confidence intervals
  3. Perform two one-sided tests

Each of these approaches requires that you define a range of clinical indifference first.

Defining a range of clinical indifference

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Establishing adequate power

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Reporting confidence intervals

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Performing two one-sided tests

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Modifications for non-inferiority trials

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Assessing Equivalence: An Alternative to the Use of Difference Tests for Measuring Disparities in Vaccination Coverage. Barker LE, Luman ET, McCauley MM, Chu SY. Am. J. Epidemiol. 2002: 156(11); 1056-1061. [Abstract]

"Proving the null hypothesis" in clinical trials. Blackwelder WC. Controlled Clinical Trials 1982: 3(4); 345-53. [Medline]

Scientific and ethical issues in equivalence trials. Djulbegovic B, Clarke M. Jama 2001: 285(9); 1206-8.

Bioequivalence of generic and brand-name levothyroxine products in the treatment of hypothyroidism. Dong BJ, Hauck WW, Gambertoglio JG, Gee L, White JR, Bubp JL, Greenspan FS. Jama 1997: 277(15); 1205-13.

Statistical Significance and Clinical Relevance: A Contradiction?. Hauschke D, Statistical Solutions. Accessed on 2003-06-24.

Sample size determination for proving equivalence based on the ratio of two means for normally distributed data. Hauschke D, Kieser M, Diletti E, Burke M. Stats in Medicine 1999: 18(1); 93-105.

Choice of Control Group in Clinical Trials. International Federation of Pharmaceutical Manufacturers Associations. Accessed on 2003-02-04.

Trials to assess equivalence: the importance of rigorous methods. Jones B, Jarvis P, Lewis JA, Ebbutt AF. British Medical Journal 1996: 313(7048); 36-39. [Medline] [Full text]

Comparison of tests and sample size formulae for proving therapeutic equivalence based on the difference of binomial probabilities. Roebruck P. Statistics in Medicine 1995: 141583-94.

Of Drafts and Gales: Speaker's Forum Monthly Article. Senn S, Statistical Solutions. Accessed on 2003-11-27.

Sample size calculations for risk equivalence testing in pharmacoepidemiology. Tubert-Bitter P, Manfredi R, Lellouch J, Begaud B. Journal of Clinical Epidemiology 2000: 53(12); 1268-1274.

Equivalence trials. Ware J, Antman E. NEJM 1997: 337(16); 1159-61. [Abstract]

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