Table 2 Baseline characteristics of study population according to total GAP score

Age, yr

56.2 ± 5.7

62.5 ± 8.9

69.0 ± 7.8

71.7 ± 7.6

72.4 ± 7.5

71.8 ± 5.9

<0.001^a

Sex, male (%)

91 (60.7)

114 (54.8)

281 (74.7)

269 (84.9)

123 (89.1)

35 (89.7)

<0.001

Duration of symptoms at diagnosis (Month)

15.9 ± 27.9

9.8 ± 15.0

10.7 ± 20.6

10.8 ± 21.8

9.5 ± 17.8

5.4 ± 12.8

0.133

Smoking

<0.001

 Non-smoker

57 (41.3)

98 (49.5)

106 (31.7)

80 (28.3)

33 (27.3)

6 (16.7)

 Former

36 (26.1)

49 (24.7)

139 (41.6)

126 (44.5)

59 (48.8)

19 (52.8)

 Current

45 (32.6)

51 (25.8)

89 (26.6)

77 (27.2)

29 (24.0)

11 (30.6)

Smoking duration (yrs)

29.1 ± 9.1

29.8 ± 11.0

37.6 ± 11.6

38.0 ± 13.0

37.4 ± 15.7

41.3 ± 9.0

<0.001^a

Smoking amounts (PYrs)

32.1 ± 18.2

30.7 ± 19.5

37.0 ± 18.0

36.6 ± 20.1

38.6 ± 25.7

40.0 ± 17.9

0.024^a

Diagnostic method (%)

<0.001

 Clinical

33 (22.0)

86 (41.3)

235 (62.5)

244 (77.0)

119 (86.2)

34 (87.2)

 Surgical

117 (78.0)

122 (58.7)

141 (37.5)

73 (23.0)

19 (13.8)

5 (12.8)

Outcome

<0.001

 Alive

92 (61.3)

118 (56.7)

167 (44.4)

114 (36.0)

36 (26.1)

10 (25.6)

 Dead

24 (16.0)

31 (14.9)

82 (21.8)

83 (26.2)

35 (25.4)

15 (38.5)

 Loss

34 (22.7)

59 (28.4)

127 (33.8)

120 (37.9)

67 (48.6)

14 (35.9)

ANA positivity

34 (33.7)

31 (28.4)

63 (37.3)

38 (29.9)

20 (35.1)

4 (23.5)

0.580

RF positivity

21 (20.4)

18 (16.5)

42 (24.1)

36 (28.3)

14 (29.2)

2 (11.1)

0.177

CRP (mg/L)

1.3 ± 3.4

2.2 ± 4.3

4.0 ± 11.5

5.9 ± 15.9

7.6 ± 22.1

14.2 ± 38.7

<0.001^a

CPI

28.0 ± 10.8

34.9 ± 12.3

35.8 ± 14.9

42.8 ± 12.8

55.7 ± 8.0

62.9 ± 6.8

<0.001^a