Table 1 Demographics and illness severity profiles of patients with ARDS with and without comorbidities

Patients, n (%)

1121 (39.9)

1692 (60.1)

631 (22.4)

290 (10.3)

286 (10.2)

112 (4.0)

584 (20.8)

613 (21.8)

Male patients, n (%)

687 (61.3)

1042 (61.6)

423 (67.0)*

182 (62.8)

190 (66.4)

77 (68.8)

337 (57.7)

388 (63.3)

Age (years), mean ± SD

56 ± 18

65 ± 15*

68 ± 13*

72 ± 12*

69 ± 13*

56 ± 11

60 ± 16*

67 ± 13*

BMI (kg/m²), median (IQR)

25.8 (23.0–29.7)

26.1 (22.8–30.9)

25.9 (22.9–30.1)

26.3 (22.9–32.1)

27.3 (24.1–32.4)*

26.7 (22.8–30.6)

24.9 (21.6–28.4)*

28.1 (24.2–34.2)*

Geo-economic areas, n (%)

 High-income Europe

628 (56.0)

893 (52.8)

357 (56.6)

159 (54.8)

140 (49.0)*

54 (48.2)

315 (54.0)

293 (47.8)*

 High-income RW

270 (24.1)

476 (28.1)

165 (26.1)

62 (21.4)

99 (34.6)*

42 (37.5)*

176 (30.1)*

209 (34.1)*

 Middle income

223 (19.9)

323 (19.1)

109 (17.3)

69 (23.8)

47 (16.4)

16 (14.3)

93 (15.9)*

111 (18.1)

Clinician recognition of ARDS, n (%)

 At baseline

373 (33.3)

514 (30.4)

141 (22.3)*

70 (24.1)*

82 (28.7)

38 (33.9)

217 (37.2)

188 (30.7)

 At any time

693 (61.8)

1042 (61.6)

345 (54.7)*

154 (53.1)*

166 (58.0)

75 (70.0)

410 (70.2)*

375 (61.2)

No longer fulfill ARDS criteria after 24 h, n (%)

195 (17.4)

291 (17.2)

111 (17.6)

58 (20.0)

59 (20.6)

19 (17.0)

94 (16.1)

98 (16.0)

ARDS Severity, n (%)

 Mild ARDS

326 (29.1)

507 (30.0)

186 (29.5)

96 (33.1)

96 (33.6)

35 (31.2)

167 (28.6)

181 (29.5)

 Moderate ARDS

516 (46.0)

822 (48.6)

323 (51.2)*

139 (47.9)

142 (49.6)

47 (42.0)

271 (46.4)

305 (49.8)

 Severe ARDS

279 (24.9)

363 (21.4)*

122 (19.3)*

55 (19.0)*

48 (16.8)*

30 (26.8)

146 (25.0)

127 (20.7)

PaO₂/FiO₂ (mmHg) at day 1 of ARDS, mean ± SD

157 ± 68

162 ± 67

162 ± 64

167 ± 67*

172 ± 68*

161 ± 71

157 ± 68

163 ± 67

pCO₂ (mmHg), at day 1 of ARDS, mean ± SD

44 ± 14

47 ± 16*

54 ± 18*

49 ± 17*

44 ± 15

41 ± 12*

44 ± 16

46 ± 16

pH, at day 1 of ARDS, mean ± SD

7.34 ± 0.12

7.33 ± 0.12*

7.32 ± 0.12*

7.33 ± 0.11

7.33 ± 0.12

7.31 ± 0.12*

7.34 ± 0.12

7.33 ± 0.13

Total SOFA adjusted Score, mean ± SD

 Day 1 of AHRF

9.3 ± 3.9

9.4 ± 4.2

8.6 ± 4.0*

9.3 ± 3.9

10.3 ± 3.6*

13.7 ± 4.1*

9.4 ± 3.9

9.5 ± 4.1

 Worst SOFA within 28 days in ICU

10.9 ± 4.2

11.2 ± 4.4

10.2 ± 4.4*

11.1 ± 4.3

11.9 ± 3.9*

15.2 ± 3.9*

11.5 ± 4.3*

11.2 ± 4.4

Non-pulmonary SOFA adjusted score, mean ± SD

 Day 1 of AHRF

6.0 ± 3.9

6.3 ± 4.1

5.4 ± 4.0*

6.2 ± 3.9

7.2 ± 3.7*

10.6 ± 4.0*

6.3 ± 4.0

6.3 ± 4.1

 Worst SOFA within 28 days in ICU

7.7 ± 4.0

8.1 ± 4.3*

7.1 ± 4.3*

8.1 ± 4.2

8.9 ± 3.9*

12.0 ± 3.7*

8.4 ± 4.2*

8.2 ± 4.3*

Type of admission, n (%)

 Medical

783 (69.9)

1375 (81.3)*

519 (82.3)*

231 (79.7)*

239 (83.6)*

94 (83.9)*

474 (81.2)*

484 (79.0)*

 Post-operative

50 (4.5)

103 (6.1)

36 (5.7)

23 (7.9)*

15 (5.2)

10 (8.9)*

40 (6.9)*

36 (5.9)

 Surgical

200 (17.8)

193 (11.4)*

66 (10.5)*

32 (11.3)*

29 (10.1)*

6 (5.4)*

69 (11.8)*

80 (13.1)*

 Trauma

88 (7.9)

21 (1.2)*

10 (1.6)*

4 (1.4)*

3 (1.0)*

2 (1.8)*

1 (0.2)*

13 (2.1)*

Number of comorbidities, n (%)

 0

1121 (100)

0 (0)

0 (0)

0 (0)

0 (0)

0 (0)

0 (0)

0 (0)

 1

–

1087 (64)

289 (46)

77 (27)

63 (22)

55 (49)

371 (64)

232 (38)

 2

–

423 (25)

215 (34)

111 (38)

107 (37)

35 (31)

147 (25)

231 (38)

 ≥ 3

–

182 (11)

127 (20)

102 (35)

116 (41)

22 (20)

66 (11)

150 (24)