To identify potential factors associated with outcome like development of ARDS, or worsening of ARDS, development of pulmonary complications, duration of ventilation, or death, univariate analyses are performed. A multivariate logistic regression model is used to identify independent risk factors. A stepwise approach is used to enter new terms into the model, with a limit of p < 0.2 to enter the terms. Time to event variables are analyzed using Cox regression and visualized by Kaplan-Meier.