Table 2 Characteristics of the case–control replication study groups

Number of participants

499

501

1764

178

373

435

863

808

Age (mean ± SD), years

64.77 ± 8.12

60.20 ± 8.66

63.63 ± 7.10

57.48 ± 9.44

67.47 ± 5.78

69.8 ± 7.49

65.53 ± 10.03

55.62 ± 9.71

Smoking history (mean ± SD), pack-years^a

54.76 ± 26.69

38.87 ± 21.07

50.29 ± 27.42

32.11 ± 24.84

66.43 ± 30.68

40.66 ± 27.85

31.98 ± 18.46

19.66 ± 13.58

FEV₁ (mean ± SD), % predicted^b

48.73 ± 18.41

97.98 ± 11.32

47.63 ± 15.62

107.83 ± 13.56

28.12 ± 7.38

99.97 ± 13.20

50.63 ± 17.44

94.91 ± 9.24

Sex (% male)

49.5%

50.1%

67.0%

57.9%

63.8%

100%

60.1%

50.1%