Spss for windows software ver 22

In this study, descriptive analyses were primarily performed, because we were interested in the current status of NIV use. All categorical variables are presented as numbers with percentages, and all continuous variables are presented as means with standard deviations. Student's t test was used to compare continuous variables, and the chi-square or Fisher exact test was used to compare categorical variables. Logistic regression analysis was performed using covariates with a p-value of <0.10 on univariate analysis to identify independent factors for NIV success (and hospital survival); we employed a backward stepwise selection method based on the likelihood ratio. IBM SPSS for Windows software ver. 22.0 (IBM Corp., Armonk, NY, USA) was used for all statistical analyses. A p-value of <0.05 was considered significant.

In this study, we collected quantitative as well as qualitative data. Statistical analysis was performed for all quantitative data by using IBM SPSS for Windows software ver. 22.0 (IBM Corp., Armonk, USA). When comparing the results before and after the course, paired sample t-test or independent sample t-test was used depending on the anonymity of data. Course evaluation data was analyzed by one-way analysis of variance.