3.3. Secondary endpoints
From 0 to 24 hours after operation, rescue parenteral analgesics were required in 29 (72.5%) and 26 (68.4%) patients in the placebo and SDE groups, respectively (QoL assessed by the SF-12 questionnaire before operation, and at POD 7 and 90. The SF-12 scores of the SDE (filled column) and placebo (open column) groups measured at different time points were compared using the 2-way repeat measures ANOVA, followed by the Bonferroni test for post hoc analysis. Results are presented as box-and-whisker plots, in which the solid horizontal lines of boxes indicate the 75th percentile, median and 25th percentile of the distribution, the upper and lower whiskers indicate the maximal and minimal values, and the dotted horizontal lines indicate mean values. *