4.7. Statistical Analysis
SECONDARY
For the secondary analysis, we used data from the primary analysis. Categorical variables are presented as proportions and were compared using the chi-square test. In the case of small numbers in groups, the Yates correction was applied. Continuous variables are presented as means with standard deviation and medians and first and third quartiles. When assessing statistical significance, Student’s For the primary analysis, the sample size was calculated to demonstrate statistical significance of differences in the assessment of the duration of invasive mechanical ventilation via endotracheal intubation or tracheotomy (hours) at 48 h after admission, assuming the standard significance level of the test 