Figure 3.. Trial sequential analysis of all trials for short-term mortality. TSA: trial sequential analysis. The required information size was 1,671 patients. The incidence in the control arm of 45.1% with a relative risk reduction of 15.0% produced an incidence of 38.3% in the corticosteroid group. The TSA-adjusted 95% confidence interval for a relative risk of 0.95 was 0.83 to 1.09 and the cumulative Z-curves crossed futility area.