Table 1 Clinical characteristics of the study population

Gender [n(%)]

0.590^a

0.559^a

0.413^a

0.280^a

 Male

356 (57.89)

319 (59.51)

46 (54.11)

273 (60.53)

 Female

259 (42.11)

217 (40.49)

39 (45.88)

178 (39.47)

Age (years, \(\overline{x}\) ± SD)

58.29 ± 13.87

60.83 ± 14.46

0.052^b

59.96 ± 14.10

0.300^b

61.68 ± 14.83

 < 0.001^b

0.324^b

Age [n (%)]

0.689^a

0.977^a

0.458^a

0.634^a

 ≤ 40

48 (7.87)

46 (8.58)

6 (7.09)

40 (8.87)

 40–50

106 (17.24)

82 (15.30)

15 (17.65)

67 (14.86)

 50–60

112 (18.21)

91 (16.98)

17 (20.00)

74 (16.41)

 60–69

217 (35.28)

186 (34.70)

31 (36.47)

155 (34.37)

 > 70

132 (21.46)

131 (24.44)

16 (18.82)

115 (25.50)

Pack-years of smoking [n(%)]^c

0.098^a

0.522^a

0.858^a

0.509^a

 0–20

543 (88.29)

455 (84.89)

70 (82.35)

385 (85.37)

 > 20

72 (11.71)

81 (15.11)

15 (17.65)

66 (14.63)

Mean pack-years (year, \(\overline{x}\) ± SD)

6.35 ± 10.86

9.27 ± 12.54

 < 0.001^b

8.76 ± 10.24

0.054^b

10.87 ± 15.67

 < 0.001^b

0.233^b