Table 1.

Multivariate analysis of factors associated with early AKI in our ARDS population

Variable	OR	95% CI	P value
Baseline characteristics
Age (years)	1.02	1.01–1.03	< 0.001
Male (Ref. female)	1.53	1.21–1.93	< 0.001
BMI (kg/m²)	1.03	1.01–1.04	0.001
Illness severity (day 1 of ARDS)
SOFA score—Cardiovascular	1.28	1.20–1.37	< 0.001
Risk factors of ARDS
Sepsis (Ref. No)	1.96	1.46–2.64	< 0.001
Non-cardiogenic shock (Ref. No)	1.82	1.23–2.69	0.003
TRALI (Ref. No)	2.42	1.43–4.09	0.001
Pancreatitis (Ref. No)	2.46	1.17–5.20	0.018
Comorbidities
Diabetes (Ref. No)	1.43	1.08–1.90	0.013
Chronic liver failure (Ref. No)	1.93	1.12–3.33	0.018
COPD (Ref. No)	0.54	0.40–0.72	< 0.001
Metabolic variables (day 1 of ARDS)
pH (per 0.01 increase)	0.94	0.93–0.95	< 0.001
Other
Medical admission (Ref. No)	1.58	1.21–2.07	0.001

Variables with a P value < 0.20 at the univariate analysis were included into a multivariable logistic regression model using a stepwise selection approach. Statistical significance was considered with a P value < 0.05 (two-tailed). No ventilator variables (i.e. tidal volume per predicted body weight, total respiratory rate, peak inspiratory pressure, PEEP, PaO₂/FiO₂ and FIO₂) selected at the univariate analysis was significant in the multivariate model n = 1765

BMI body mass index, SOFA sequential organ failure assessment, TRALI transfusion related acute lung injury, COPD chronic obstructive pulmonary disease