5.

Trial sequential analysis of 12 trials with low risk of bias assessing vitamin A versus placebo was constructed based on a mortality of 13.6% in the control group, a relative risk reduction of 5% of vitamin A, a type I error of 5%, and a type II error of 20% (80% power). There was diversity (D² = 65%). The diversity‐adjusted required information size was 108,645 participants.The trial sequential analysis revealed that the cumulative Z‐curve (blue line) did not cross the trial sequential monitoring boundary (red line). Neither did the cumulative Z‐curve reach the area of futility, which was not constructed by the program due to too little information.