%0 Journal Article
%T Non-inferiority in cancer clinical trials was associated with more lenient margins and higher hypothesized outcome event rates.
%A He Y
%A Shu C
%A Li T
%A Wu Q
%A Wang Z
%A Chen X
%A Shen X
%J J Clin Epidemiol
%V 139
%N 0
%D Nov 2021
%M 34437946
%F 7.407
%R 10.1016/j.jclinepi.2021.08.020
%X <B>OBJECTIVE: </B>To identify potential bias in non-inferiority design of published cancer trials, and to provide suggestions for future practice.<BR><B>METHODS: </B>We systematically searched MEDLINE, Embase and CENTRAL databases (until April 17, 2020) to obtain non-inferiority phase III cancer trials and protocols. Distribution of essential characteristics and study design parameters was compared between trials with and without concluding non-inferiority using multivariable logistic regression.<BR><B>RESULTS: </B>A total of 291 eligible trials were included. We observed that increased odds of concluding non-inferiority was significantly associated with more lenient non-inferiority margins (OR = 1•94, 95% CI 1•02-3•69) and higher hypothesized event rate (OR = 1•24, 95% CI 1•06-1•47). Trials that established non-inferiority adopted margins that were more dispersedly distributed (dispersion OR = 2•90, 95% CI 1•88-4.48).<BR><B>CONCLUSIONS: </B>Although limited by the exploratory nature, our study demonstrated existence of possible distorted non-inferiority design which could incur excess non-inferiority in cancer clinical trials. Pre-registration and transparent reporting of detailed non-inferiority design is imperative for future research.