Table 3.

Multivariate analysis of predictors of 90-day mortality

	Odds ratio	95% CI	p value
Model A
Age	1.135	1.004–1.285	0.044
BMIa	0.775	0.644–0.934	0.007
Charlson score	1.220	0.593–2.510	0.589
High-flow nasal oxygen before intubation	0.963	0.075–12.357	0.977
First wave	0.669	0.03–14.698	0.799
RESP score	1.117	0.673–1.853	0.669
Dexamethasone usea	5.211	0.375–72.412	0.219
Hydroxychloroquine use	0.673	0.108–4.186	0.671
Time from ICU admission to ECMO	1.108	0.951–1.291	0.187
Model B
Age	1.187	1.035–1.362	0.014
BMIa	0.631	0.462–0.862	0.004
Charlson score	1.482	0.753–2.917	0.255
High-flow nasal oxygen before intubation	1.674	0.132–21.228	0.691
First wave	0.817	0.03–21.912	0.904
PRESERVE score	0.508	0.242–1.067	0.074
Dexamethasone useb	4.942	0.308–79.223	0.259
Hydroxychloroquine use	0.499	0.074–3.361	0.475
Time from ICU admission to ECMO	1.175	0.984–1.403	0.075

Model A: variables included: (a) quantitative: age, BMI, RESP score, Charlson score, time from ICU (intensive care unit) admission to ECMO; (b) qualitative: pandemic waves (first vs. second), dexamethasone use, hydroxychloroquine use, high-flow nasal O₂ before intubation. Hosmer–Lemeshow test p = 0.558

Model B: variables included: (a) quantitative: age, BMI, PRESERVE score, Charlson score, time from ICU (intensive care unit) admission to ECMO; (b) qualitative: pandemic waves (first vs. second), dexamethasone use, hydroxychloroquine use, high-flow nasal O₂ before intubation. Hosmer–Lemeshow test, p = 0.182

BMI body mass index (g/m²), CI confidence interval, PRESERVE score [19] PRedicting dEath for SEvere ARDS on VV-ECMO score, RESP score [17] Respiratory Extracorporeal Membrane Oxygenation Survival Prediction Score

^a3 patients had missing data for BMI

^bPatients receiving dexamethasone 6 mg per day or equivalent dose of corticosteroids