4.

Trial Sequential Analysis of mortality at maximal follow‐up: based on an alpha error of 2.5%, power of 90% (beta error of 10%), a relative risk reduction (RRR) of 20%, the control group proportion (Pc) of 50%, and observed heterogeneity (0%), the a priori information size (APIS) was 2011. As shown in the figure, the cumulative Z‐curve (blue line) do not cross any of trial sequential monitoring boundaries (red lines). They do not cross the conventional alpha boundary of 2.5% (green line) either.