Table 1.

Baseline characteristics

	All patients	Subphenotype 1 (non-recruitable)	Subphenotype 2 (recruitable)	p value
n	99	62	37
Demographics
Age (years)	63 (10)	65 (9)	60 (10)	0.008
Gender = Male (%)	68 (69)	45 (73)	23 (62)	0.391
BMI (kg m−2)	29.18 (6.29)	28.57 (5.37)	30.19 (7.55)	0.218
COVID symptoms duration (days)	9 [5, 12]	8 [5, 10]	10 [7, 14]	0.027
COVID ICU stay at inclusion (days)	5 [1, 11]	5 [1, 9]	7 [0, 12]	0.633
Respiratory parameters
Respiratory rate (min−1)	25 (7)	24 (7)	28 (7)	0.003
Tidal volume (mL)	444 (131)	440 (123)	451 (144)	0.681
Tidal volume / IBW (mL kg−1)	6.47 [5.67, 7.90]	6.36 [5.69, 7.63]	6.76 [5.67, 7.90]	0.395
Arterial pH	7.37 [7.30, 7.43]	7.38 [7.34, 7.44]	7.32 [7.26, 7.42]	0.005
PEEP before recruitment (cmH2O)	10 [8, 12]	10 [8, 11]	10 [10, 12]	0.008
Driving pressure (cmH2O)	12 [8, 17]	10 [7, 13]	15 [12, 20]	< 0.001
Ventilatory ratio	1.57 [1.23, 2.40]	1.43 [1.12, 1.92]	2.40 [1.38, 3.05]	0.001
Compliance of respiratory system (cmH2O)	33 [24, 58]	42 [28, 73]	29 [21, 39]	0.004
Severity
Apache II score	15 [11.5, 20.5]	20 [12, 21.75]	12 [10, 20]	0.042
PaO2/FiO2 (mmHg)	106 [80, 138]	130 [98, 158]	81 [72, 103]	< 0.001
ARDS category (%)				< 0.001
Mild	6 (6.2)	6 (10)	0 (0)
Moderate	47 (48.5)	36 (60)	11 (29.7)
Severe	44 (45.4)	18 (30)	26 (70.3)
Outcomes
Duration of mechanical ventilation (days)	16 [9, 27]	15 [7.5, 25.5]	16 [12, 27]	0.189
Duration of ICU stay (days)	18 [11, 31]	18 [10, 30.5]	17.5 [13, 32.5]	0.266
Successfully extubated (%)	39 (46)	27 (53)	12 (35)	0.168
ICU mortality (%)	43 (51)	23 (45)	20 (59)	0.308

Data are shown for the entire cohort and stratified for the two subphenotypes identified by the latent class analysis. BMI Body mass index, COVID-19 coronavirus disease 2019, ICU intensive care unit, IBW ideal body weight, PEEP positive end-expiratory pressure