Table 5 Crude and adjusted hazard ratios (HR) of mortality for the disease severity in Cox regression model

GAP stage

  ≥ 1

143 (59)

2.415 (1.511–3.860)***

2.258 (1.339–3.808)**

 1

110 (41)

Reference

Reference

FVC% predicted

  < 75%

133 (55)

1.741 (1.131–2.680)*

2.118 (1.341–3.346)**

  ≥ 75%

110 (45)

Reference

Reference

DLCO% predicted

  < 55%

159 (65)

2.499 (1.455–4.290)**

2.646 (1.506–4.650)**

  ≥ 55%

84 (35)

Reference

Reference

TLC % predicted

  < 65%

105 (43)

2.327 (1.523–3.554)***

2.195 (1.422–3.389)***

  ≥ 65%

138 (57)

Reference

Reference

CPI

  > 45

136 (56)

3.246 (1.986–5.303)***

3.619 (2.158–6-071)

  ≤ 45

107 (44)

Reference

Reference