Table 2.

Multivariable models on the association between ICU mortality and static compliance of respiratory system (model 1) and driving pressure (model 2) at the first day of invasive controlled mechanical ventilation

	OR (95% CI)	p value*
Model 1
Age (years)	1.10 (1.05–1.15)	< 0.01
Static compliance of the respiratory system (per ml/cmH2O increase)	0.98 (0.96–1.00)	0.03
Model 2
Age (years)	1.10 (1.05–1.15)	< 0.01
Driving pressure (per cmH2O increase)	1.12 (1.00–1.24)	0.04

Data are expressed as Odds ratio (OR) and 95% Confidence Interval (CI)

^*Stepwise regression approach, combining forward and backward selection methods (with a significance level of 0.05 both for entry and retention), was applied to select predictors in the final multivariable model. Independent variables finally entered in the multivariable models were age, gender, body mass index, SOFA score at ICU admission, Charlson comorbidity index, PaO₂/FiO₂, PaCO₂, VT/kg IBW and respiratory rate. Multicollinearity analysis is reported as Additional file 3