Statistical methods
Statistical analyses were performed with the Statistical Package for the Social Sciences for Windows (SPSS version 24.0; IBM Corp, Armonk, NY, USA). Depending on the outcomes and distribution, the following tests were used to compare outcomes between two groups of patients (patients with a history of <2-week tracheostomy and those with a >2-week tracheostomy): Chi-square and Mann-Whitney U Test. The relationship between patient epidemiological and clinical features was investigated with Spearman analysis and multivariate analysis. A level of significance of p<0.05 was used.