Table 2 Log-rank test for risk factors for an acute exacerbation of idiopathic pulmonary fibrosis

 S or Ex

32

20

0.918

 N

9

4

 Yes

10

8

0.042

 No

31

16

 II or III

11

12

0.002

 I

25

10

  ≥ 180

32

22

0.048

  < 180

9

2

KL-6

  ≥ 946

18

16

0.292

  < 946

21

8

  ≥ 194.7

22

18

0.014

  < 194.7

17

6

  ≥ 10.15

13

13

0.085

  < 10.15

28

11

  ≥ 1.77

34

22

0.048

  < 1.77

7

2

  ≥ 3.21

21

17

0.009

  < 3.21

20

7

 Yes

7

8

0.443

 No

34

16

 Yes

3

6

0.009

 No

38

18

 Yes

8

6

0.963

 No

33

18

 Yes

8

5

0.547

 No

33

19