Statistical analysis
The data analysis was performed using SPSS 25.0 software (IBM, Armonk, NY). The count data was expressed in the form of numbers (percentage). The independent sample t-test was used to compare continuous, normally distributed data expressed as mean ± standard deviation; the Mann Whitney U test was used to compare non-normally distributed data expressed as median (interquartile range). Pearson’s Chi-squared or Fisher’s exact tests were used to compare categorical data. Kruskal Wallis test followed by Tamhane’s post-hoc pairwise comparisons were used to compare DTF and DE values of groups according to post-extubation intervention requirements. All tests were two-tailed, and statistical significance was defined as a p-value less than 0.05. The receiver operating characteristic analysis (ROC) was used to determine the predictive value of each index in this study. The optimal threshold, along with its sensitivity and specificity, was determined using the Yuden index.