{Reference Type}: Journal Article {Title}: Non-inferiority in cancer clinical trials was associated with more lenient margins and higher hypothesized outcome event rates. {Author}: He Y;Shu C;Li T;Wu Q;Wang Z;Chen X;Shen X; {Journal}: J Clin Epidemiol {Volume}: 139 {Issue}: 0 {Year}: Nov 2021 {Factor}: 7.407 {DOI}: 10.1016/j.jclinepi.2021.08.020 {Abstract}: OBJECTIVE: To identify potential bias in non-inferiority design of published cancer trials, and to provide suggestions for future practice.
METHODS: 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.
RESULTS: 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).
CONCLUSIONS: 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.