Statistical analysis
chest wall rigidity
REGRESSION
The sample size was predetermined by the Chi-square Sample Size calculation using SigmaPlot 14.5 (Systat Software Inc. San Jose, USA) based on the assumption that the incidence of remifentanil-induced chest wall rigidity, which was considered the primary endpoint, would be 15% and 45% in the hypnotic-remifentanil and remifentanil-hypnotic group, respectively. A total of 103 patients were required, with a significance level of 0.05 (α = 0.05) and power of 80% (β = 0.20). To allow attrition, the total sample size was increased to 125.All statistical analyses were performed using SigmaPlot 14.5. Continuous variables were compared using one-way analysis of variance (ANOVA) with Tukey post-hoc test after normality test using Shapiro–Wilk test. Categorial variables were analyzed using chi-square test. Vital signs, including mean arterial pressures and heart rate, were analyzed using two-way repeated measures ANOVA. The Holm-Sidak method and Bonferroni correction were used for multiple comparisons. Based on the statistical comparison, univariate logistic regression analysis was performed to identify possible risk factors for the development of chest wall rigidity, with the odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for each variable. All data are expressed as the number of patients, means (SD), or numbers (percentages). A 