Appendix Table 1.

Upper 95% confidence bounds for HR and RD measures from a noninferiority study designed using RMST

Total study size	Accrual rate (per day)	The entire study time (days)	Total number of events observed	Estimated upper bound of 95% confidence interval for hazard ratio	Estimated upper bound of 95% confidence interval for risk difference at 900 days
2216	5	949	160	1.56	4.4%
2172	10	924	176	1.53	4.0%
2094	30	908	182	1.52	3.6%

Abbreviation: HR = hazard ratio; RD = risk difference; RMST = restricted mean survival time

Estimates of upper 95% confidence bounds for the HR and RD were calculated, assuming the following fixed inputs: total sample size, accrual rate, and total study time. All these configurations were figured out, so that the estimated upper bound of 95% confidence interval for difference in RMST at 900 days can meet a noninferiority margin of 18 days (2% of the 900 days).