Spss statistics software version 23

Statistical analyses were implemented using the SPSS Statistics software version 23.0 (IBM Corp, N.Y., USA). The significance level (type I error) was set to 0.05. The reliability of the statistical analysis was verified by checking the design assumptions of normality, homogeneity of variance, and continuity of data. To ensure that the normalcy assumption is true, a Kolmogorov-Smirnova test was performed [76 (link)]. A two-way analysis of variance (ANOVA) for the repeated measures design was implemented to test the main and interaction effects of the instruction method and task complexity on the dependent variables, including the power spectra density of EEG wave bands, perceived workload (NASA-TLX), and total training time. Significant interaction effects were further examined using simple effect analysis. The paired t-test was used for pairwise comparisons of the interaction effects of the task complexity levels. An independent sample t-test was performed for pairwise comparisons of the interaction effects of the levels of the instruction methods. The mean and standard deviation were calculated for all dependent variables. Furthermore, the effect size was determined by calculating the percentage of variance in the dependent variables that can be attributed to the specific independent variable using the partial eta-squared value (2).

Univariate and multivariate Cox proportional hazards regression analyses were performed to assess the association between baseline parameters and BCR-free survival. In addition, univariate and multivariate logistic regression were carried out for the significant factors of AP, and the Kaplan-Meier method with log-rank tests were performed to estimate and compare oncologic outcomes according to AP and PSA.
Receiver operator characteristic (ROC) curve analysis was performed to determine optimal cut-off value via the area under the curve (AUC). A total AUC score of 0.8–0.9 was interpreted as an excellent level and 0.7–0.8 as a good level.
Significant variables from univariate analysis were included in the multivariate analysis. Comparisons with p < 0.05 were considered statistically significant. All statistical analyses were performed using SPSS Statistics software, version 23.0 (IBM, Armonk, NY, USA).

Numerical variables with normal distribution were shown as mean ± standard deviation (SD), and those without normal distribution were described as the median and interquartile range (IQR). Categorical variables are presented as numbers and percentages. Student’s t-test or Mann-Whitney U test was utilized to compare the differences between continuous variables, and the Chi-square test or Fisher’s exact test was used for categorical variables. Multivariate analysis was performed to assess the association between selected metabolite levels and auditory recovery. All statistical analyses were conducted with SPSS statistics software version23.0 (IBM, Chicago, IL, United States), and p values <0.05 were defined as statistically significant.