Sample size and statistical analysis
delirium, postoperative delirium, cognitive dysfunction
REGRESSION
The sample size was calculated using G*Power 3 software, with a power of 80% and a type I error of 5% (α = 0.05 and β = 80%) on the one-tailed test, to detect an effect size of 0.4 to 0.5 in the incidence of postoperative delirium, which is the primary outcome measure of this study. The minimum required sample size was 60 patients admitted and scheduled for emergency surgery under general anesthesia (divided into three equal groups of 20 patients each).The data were verified, coded by the researchers, and analyzed using SPSS version 24. Descriptive statistics: means, standard deviations (SD), and percentages were calculated. The chi-square test was used to compare the difference in the distribution of postoperative delirium incidence among different groups. The Shapiro-Wilk test was used to test data normality. For continuous variables with more than two categories, the one-way analysis of variance (ANOVA) test was calculated to test the mean differences of the data that follow a normal distribution, and an independent post-hoc test was calculated using Bonferroni corrections. The multivariate logistic regression analysis was used to detect the independent association between treatment drugs and the incidence of postoperative delirium and cognitive dysfunction. A p-value equal to or less than 0.05 was considered significant.