Table 2 Baseline and follow-up mean PAP analysis among studied patients with different etiologies of chronic respiratory failure

Overlap syndrome

n = 15

n = 15

n = 14

n = 12

n = 11

Min.–max

30.0–55.0

25.0–55.0

25.0–52.0

20.0–52.0

20.0–35.0

Mean ± SD

39.93 ± 8.04

37.40 ± 9.44

34.36 ± 8.35

30.42 ± 8.60

24.64 ± 4.50

^tp

< 0.001*

< 0.001*

< 0.001*

< 0.001*

OHS

n = 14

n = 14

n = 14

n = 12

n = 11

Min.–max

28.0–55.0

26.0–54.0

26.0–50.0

24.0–50.0

22.0–50.0

Mean ± SD

39.43 ± 8.24

37.36 ± 8.71

35.14 ± 8.31

32.08 ± 9.41

28.18 ± 8.05

^tp

0.001*

< 0.001*

< 0.001*

< 0.001*

COPD

n = 6

n = 6

n = 5

n = 5

n = 5

Min.–max

35.0–45.0

33.0–45.0

30.0–45.0

28.0–45.0

24.0–46.0

Mean ± SD

39.50 ± 3.94

38.83 ± 4.45

35.40 ± 6.19

34.60 ± 6.58

32.60 ± 8.71

^tp

0.175

0.021*

0.020*

0.037*

RTD

n = 9

n = 9

n = 9

n = 9

n = 8

Min.–max

35.0–55.0

32.0–55.0

30.0–53.0

26.0–53.0

22.0–50.0

Mean ± SD

43.67 ± 6.38

41.33 ± 6.91

38.33 ± 7.04

34.78 ± 8.04

29.88 ± 8.82

^tp

0.002*

 < 0.001*

 < 0.001*

 < 0.001*

NMDs

n = 4

n = 4

n = 4

n = 4

n = 2

Min.–max

27.0–40.0

27.0–38.0

25.0–40.0

22.0–40.0

20.0–25.0

Mean ± SD

32.25 ± 5.56

31.0 ± 5.23

30.0 ± 6.78

28.0 ± 8.12

22.50 ± 3.54

^tp

0.194

0.078

0.065

0.105