Table 1 Patient characteristics

 Age

74 (62 to 85)

75 (64 to 86)

75 (63 to 82)

72 (62 to 85)

 Sex

66

29

19

18

 Men (%)

83.54%

85.29%

76%

90%

 Smoking history

61

25

18

18

  Yes (%)

77.22%

73.53%

72%

90%

 Current smoker

13

5

4

4

  (%)

16.46%

14.71%

16%

20%

 High fever

43

15

18

10

  Yes (%)

54.43%

44.12%

72%

50%

 Sore throat

35

8

22

5

  Yes (%)

44.31%

23.52%

88%

25%

 Worsening cough

50

22

16

12

  Yes (%)

63.29%

64.77%

64%

60%

 Worsening dyspnea

75

32

24

19

  Yes (%)

94.94%

94.12%

96%

95%

Pre-existing CF-IIPs

 IPF

59

25

19

15

 UCIP

20

9

6

5

Prior treatment

 No treatment

47

17

14

16

 Corticosteroid

9

3

2

4

 Corticosteroid + IS

6

4

2

0

 Pirfenidone

9

4

5

0

 Nintedanib

4

3

1

0

 Corticosteroid + Nintedanib

4

3

1

0

HRCT pattern at AE-IIPs onset

 Diffuse

34

17

7

10

 Multifocal

14

7

5

2

 Peripheral

31

10

13

8

 P/F ratio

168 (83.2 to 344.1)

n = 79

173.7 (54.4 to 380.9)

n = 34

213.3 (46.7 to 476.7)

n = 25

134.2 (55.5 to 458.6)

n = 20

 FVC (L)

2.35 (0.94 to 3.01)

n = 39

2.29 (1.53 to 3.07)

n = 18

1.51 (0.78 to 2.76)

n = 11

2.78 (1.94 to 4.45)

n = 10

 %FVC (%)

65.55 (39.85 to 84.02)

n = 39

64.90 (47.20 to 82.66)

n = 18

51.33 (33.34 to 81.62)

n = 11

73.70 (57.00 to 87.90)

n = 10

 VC (L)

2.49 (1.33 to 3.05)

n = 39

2.42 (1.43 to 3.15)

n = 18

1.64 (0.83 to 3.16)

n = 11

2.85 (2.08 to 4.32)

n = 10

 %VC (%)

70.70 (44.60 to 90.22)

n = 39

67.35 (47.00 to 93.18)

n = 18

52.00 (35.16 to 81.33)

n = 11

81.11 (59.91 to 119.41)

n = 10

 DLco (mL/min/mmHg)

(3.85 to 11.35)

n = 30

6.44 (3.73 to 12.53)

n = 16

7.74 (2.92 to 11.51)

n = 7

8.04 (4.08 to 10.09)

n = 7

 %DLco (%)

29.90 (16.55 to 40.02)

n = 30

25.35 (16.05 to 52.77)

n = 16

33.70 (12.40 to 45.50)

n = 7

32.41 (18.11 to 44.42)

n = 7

 KL-6 (IU/L)

1117 (572 to 2701)

n = 79

1312 (692 to 2663)

n = 34

1019 (222 to 3509)

n = 25

1372 (659 to 3528)

n = 20

 SP-D (mg/dL)

364 (45 to 2711)

n = 63

370 (77 to 2430)

n = 29

320 (20 to 1170)

n = 20

370 (133 to 3180)

n = 14

 LDH (IU/L)

365 (193 to 539)

n = 79

346 (193 to 546)

n = 34

327 (201 to 765)

n = 25

436 (175 to 652)

n = 20

 WBC (/μL)

10,700 (6300 to 15,400)

n = 79

10,400 (6200 to 17,880)

n = 34

10,600 (5700 to 22,900)

n = 25

12,600 (2500 to 22,900)

n = 20

 CRP (mg/dL)

8.5 (0.7 to 25)

n = 79

7.3 (0.7 to 22)

n = 34

11.1 (0.87 to 36)

n = 25

7.5 (1.3 to 25.3)

n = 20

 Procalcitonin (ng/mL)

0.12 (0.01 to 0.74)

n = 70

0.15 (0.01 to 0.58)

n = 32

0.33 (0.07 to 0.74)

n = 21

0.09 (0.01 to 0.31)

n = 17

 D-dimer (mg/dL)

3.6 (1.38 to 74.2)

n = 74

3 (1.8 to 83)

n = 31

2.6 (1.3 to 21.1)

n = 24

6.1 (1.2 to 41.0)

n = 19