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How to establish equivalence when data are censored: A randomized trial of treatments for B non‐Hodgkin lymphoma
Author(s) -
ComNougue C.,
Rodary C.,
Patte C.
Publication year - 1993
Publication title -
statistics in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.996
H-Index - 183
eISSN - 1097-0258
pISSN - 0277-6715
DOI - 10.1002/sim.4780121407
Subject(s) - hazard ratio , confidence interval , statistics , equivalence (formal languages) , log rank test , null hypothesis , mathematics , proportional hazards model , medicine , randomized controlled trial , oncology , econometrics , discrete mathematics
Interest in equivalence trials has been increasing for many years, though the methodology which has been developed for such trials is mainly for uncensored data. In cancer research we are more often concerned with survival. In an efficacy trial, the null hypothesis specifies equality of the two survival distributions, but in an equivalence trial, a null hypothesis of inequivalence H 0 has to be tested. The usual logrank test has to be modified to test whether the true value r of the ratio of hazard rates in two treatment groups is at least equal to a limit value r 0 . If prognostic factors have to be taken into account, the Cox model provides tests of H 0 , and a useful confidence interval for the adjusted relative risk derived from the regression parameter for the treatment indicator. An equivalence trial of maintenance therapy was carried out in children with B non‐Hodgkin lymphoma, and serves as an illustration.