Statistical analysis
Categorical data are presented as numbers, percentages, and rates, while
continuous data as mean and standard deviation, or median and range,
when appropriate. A chi square test or Fisher’s exact test were
performed to analyze categorical data, while unpaired Student T test or
Mann Whitney test were applied depending on patients’ distribution.
Two-way analysis of variance for repeated measures was applied to verify
respiratory differences in the two groups. Multivariate logistic
regression analysis (MLRA) was used to assess the effect of PEEP on
intubation, adjusted for the covariates listed as baseline features.
Variation inflation factor (VIF) was used to evaluate for collinearity.
Variables with VIF>2 were considered colinear and excluded
from the analysis. A p-value of <0.05 was considered
statistically significant. Statistical analysis was performed using the
GraphPad Prism 8.0 software package (GraphPad Software, San Diego, CA).