Table 4

Univariable and multivariable analysis, by generalised estimating equation models, for development of acute respiratory distress syndrome over the course of mechanical ventilation

	Univariable			Multivariable
	OR	95% CI	p-Value	OR	95% CI	p-Value
Age, per year	0.99	0.98 to 1.00	0.861
Gender
Male	1 (reference)
Female	0.90	0.65 to 1.26	0.550

Body mass index by category
Underweight	1 (reference)			1 (reference)
Normal	1.33	0.57 to 3.10	0.507	1.62	0.58 to 4.50	0.352
Overweight	2.04	0.86 to 4.84	0.106	2.23	0.80 to 6.22	0.126
Obese/severely obese	2.59	1.11 to 6.06	0.028	3.07	1.07 to 8.84	0.037
SAPS II, per point	1.00	0.99 to 1.01	0.493

Reason of mechanical ventilation
Neurological disease	1 (reference)			1 (reference)
Chronic pulmonary disease	0.94	0.31 to 2.85	0.916	0.82	0.22 to 3.07	0.773
Acute respiratory failure without a priori risk for ARDS^*	1.53	0.87 to 2.70	0.136	1.10	0.60 to 1.99	0.752
Trauma	2.30	1.17 to 4.53	0.021	1.37	0.69 to 2.68	0.263
Sepsis	2.59	1.16 to 5.80	0.016	1.85	0.81 to 4.22	0.144
Pneumonia	3.32	1.72 to 6.40	<0.001	2.15	1.00 to 4.65	0.050
Aspiration	4.98	2.22 to 11.20	<0.001	3.48	1.32 to 9.17	0.012
Ventilator associated pneumonia	1.91	0.92 to 3.99	0.083	1.13	0.49 to 2.62	0.765

Sepsis over the course of mechanical ventilation
No	1 (reference)			1 (reference)
Pulmonary	2.58	1.37 to 4.84	0.003	1.83	0.88 to 3.80	0.105
Extrapulmonary	2.94	1.49 to 5.78	0.002	2.71	1.37 to 5.38	0.004
Shock over the course of mechanical ventilation	3.28	2.26 to 4.76	<0.001	2.50	1.62 to 3.87	<0.001
Tidal volume (ml/kg predicted body weight), per unit	1.02	0.97 to 1.07	0.469
PEEP, per cmH2O	1.31	1.22 to 1.39	<0.001	1.04	1.01 to 1.07	0.006

↵* This variable includes: Postoperative acute respiratory failure, congestive heart failure, cardiac arrest.