Validating Restricted Mean Survival Time Estimates From Reconstructed Kaplan-Meier Data Against Original Trial Individual Patient Data From Trials Conducted by the Canadian Cancer Trials Group

•Recently, studies examining restricted mean survival time (RMST) based on reconstructed individual patient data (IPD) have gained attention in literature. Nevertheless, although this method has been validated for other survival endpoints, these works are predicated on the unvalidated assumption that RMST may be accurately estimated based on reconstructed IPD. This study addresses the present discussion in the literature, regarding the validity of survival estimates calculated from reconstructed IPD.•We found RMST estimates derived from reconstructed IPD displayed excellent accuracy and low predictive error compared with the gold-standard RMST estimates calculated using the original trial IPD.•RMST based on reconstructed IPD may allow physicians, patients, and policy makers to accurately examine the true absolute magnitude of the survival benefits of novel anticancer therapies.