Sensitivity analyses
Several sensitivity analyses were conducted in the whole cohort in order to evaluate the robustness of the counterfactual methods. In the MSM model, estimate accuracy increases as interval length decreases: the HRs which calculate weights using 180 days as the time-interval (compared to 50 days selected for the main analysis) for the extended group compared to the ST group, were 0.57 (0.51–0.65) and 0.77 (0.66–0.89), evaluating iDFS and OS outcomes, respectively. The RPSFTM method produced an iDFS HR of 0.72 (0.59–0.88) and 0.81 (0.71–0.93) and an OS HR of 0.76 (0.58–0.99) and 0.85 (0.73-99) with and without recensoring, respectively (Supplementary Table 