The incidence of postoperative nausea showed a trend toward reduction in the conventional meta-analysis (RR 0.49, 95% CI 0.23–1.04; p = 0.057; I 2 = 34%); although TSA suggested a possible benefit, this finding should be considered exploratory.
TSA crossed the monitoring boundary under the selected assumptions; however, because the conventional meta-analysis narrowly missed statistical significance and TSA is sensitive to assumptions regarding anticipated effect size and control event rate, this finding should be interpreted cautiously and considered exploratory ( Figure 10 ).