Dose-response relationship in the context of a maintenance randomized control trial: reanalysis of the PRODIGE 9 trial

Introduction The dose-response relationship is considered as one of the major criteria when the causality of a relationship between an exposure and an outcome is discussed. This criterion is mainly studied in observational studies but may be also of interest in Randomized Controlled Trial (RCT), particularly if the administered dose of treatment varies over time and between patients. Maintenance trials with a long follow-up meet these characteristics. We reanalyzed a maintenance trial in digestive oncology (PRODIGE 9 trial) in order to explore the dose-response relationship between the maintenance treatment and overall survival (OS). Methods The PRODIGE 9 study was a maintenance trial asses…