Table 1 Characteristics of the study subjects categorized by spirometry-confirmed COPD in the development cohort

From: An accurate prediction model to identify undiagnosed at-risk patients with COPD: a cross-sectional case-finding study

 

All

Total subjects

 

COPD patients divided by GOLD stage

 

COPD

Non-COPD

P a

GOLD I

GOLD II

GOLD III–IV

P b

Numbers

301

147

154

 

40

82

25

 

Age, years

70.7 ± 13.2

75.2 ± 11.3

66.5 ± 13.5

<0.001

77.9 ± 9.9c

75.0 ± 11.2c

72.3 ± 10.8

<0.001

Gender, male (%)

287 (95)

139 (95)

148 (96)

0.524c

39 (98)

77 (94)

23 (92)

0.652c

Current smoker (%)

128 (43)

56 (38)

72 (47)

0.129c

14 (35)

30 (37)

12 (48)

0.315c

Smoking pack-years

45.4 ± 25.0

50.6 ± 26.0

40.3 ± 20.1

<0.001

52.3 ± 29.9d

49.5 ± 25.9d

51.7 ± 19.8

0.004

Peak flow meter

Best PEFR (L/min)

383 ± 148

290 ± 120

472 ± 113

<0.001

403 ± 101d

270 ± 85d,e

174 ± 96d,e,f

<0.001

PEFR, % pred.

79 ± 28

63 ± 25

95 ± 20

<0.001

89 ± 19

57 ± 18d,e

38 ± 16d,e,f

<0.001

AT score

Total

8.1 ± 6.9

10.2 ±8.0

6.1 ± 4.9

<0.001

5.7 ± 4.1

11.4 ± 8.4d,e

13.2 ± 8.6d,e

<0.001

Cough

1.8 ± 1.4

2.0 ± 1.4

1.6 ± 1.3

0.011

1.7 ± 1.2

2.2 ± 1.6d

1.9 ± 1.3

0.018

Phlegm

1.8 ± 1.4

2.0 ± 1.5

1.5 ± 1.3

0.001

1.6 ± 1.2

2.1 ± 1.5d

2.4 ± 1.6d

0.001

Chest tightness

1.0 ± 1.3

1.2 ± 1.5

0.8 ± 1.0

0.002

0.7 ± 1.1

1.4 ± 1.6d,e

1.4 ± 1.6

<0.001

Breathlessness

1.1 ± 1.5

1.6 ± 1.7

0.7 ± 1.0

<0.001

0.3 ± 0.6

1.9 ± 1.8d,e

2.4 ± 1.6d,e

<0.001

Activity limitation

0.6 ± 1.2

0.9 ± 1.5

0.3 ± 0.9

<0.001

0.3 ± 0.9

0.9 ± 1.6d

1.5 ± 1.6d,e

<0.001

Confidence

0.3 ± 1.0

0.5 ± 1.2

0.6 ± 1.1

<0.001

0.1 ± 0.2

0.6 ± 1.4d,e

1.0 ± 1.5d,e

<0.001

Sleep

0.7 ± 1.2

0.8 ± 1.3

0.6 ± 1.1

0.114

0.4 ± 0.8

1.0 ± 1.4e

1.1 ± 1.2

0.009

Energy

0.9 ± 1.2

1.2 ± 1.4

0.6 ± 1.0

<0.001

0.6 ± 1.0

1.4 ± 1.5d,e

1.4 ± 1.3d,e

<0.001

Spirometry, pre-BD

FEV1 (L)

1.96 ± 0.75

1.47 ± 0.53

2.44 ± 0.62

<0.001

1.93 ± 0.50d

1.43 ± 0.39d,e

0.87 ± 0.20d,e,f

<0.001

FEV1, % pred.

81 ± 24

66 ± 20

96 ± 16

<0.001

90 ± 12d

62 ± 9d,e

39 ± 9d,e,f

<0.001

FVC (L)

2.83 ± 0.80

2.52 ± 0.77

3.12 ± 0.72

<0.001

2.99 ± 0.74

2.47 ± 0.68d,e

1.95 ± 0.66d,e,f

<0.001

FVC, % pred.

84 ± 17

79 ± 19

89 ± 14

<0.001

95 ± 14

76 ± 15d,e

62 ± 17d,e,f

<0.001

FEV1/FVC (%)

68 ± 14

58 ± 12

78 ± 7

<0.001

65 ± 7d

58 ± 11d,e

47 ± 14d,e,f

<0.001

Spirometry, post-BD

FEV1 (L)

2.05 ± 0.75

1.56 ± 0.55

2.52 ± 0.61

<0.001

2.05 ± 0.52d

1.50 ± 0.38d,e

0.94 ± 0.22d,e,f

<0.001

FEV1, % pred.

85 ± 23

70 ± 20

99 ± 16

<0.001

96 ± 12

66 ± 8d,e

42 ± 8d,e,f

<0.001

FVC (L)

3.02 ± 0.93

2.82 ± 1.07

3.20 ± 0.72

<0.001

3.22 ± 0.73

2.68 ± 0.68d,e

2.21 ± 0.66d,e,f

<0.001

FVC, % pred.

89 ± 17

86 ± 19

92 ± 15

0.003

103 ± 14d

83 ± 16d,f

70 ± 17d,e,f

<0.001

FEV1/FVC (%)

68 ± 15

56 ± 12

79 ± 6

<0.001

63 ± 5d

56 ± 11d,e

44 ± 14d,e,f

<0.001

  1. Data are presented as means ± standard deviation
  2. % pred. percent predicted value, BD bronchodilation, CAT COPD assessment test, COPD chronic obstructive pulmonary disease, FEV1 forced expiratory volume in the first second, FVC forced expiratory capacity, PEFR peak expiratory flow rate
  3. aIndependent t-test, COPD vs. non-COPD
  4. bOne-way ANOVA test, compare 4 groups: non-COPD, GOLD I, GOLD II, and GOLD III-IV
  5. cChi-square test
  6. dPost-hoc Bonferroni test, P < 0.05, vs. non-COPD
  7. ePost-hoc Bonferroni test, P < 0.05, vs. GOLD I
  8. fPost-hoc Bonferroni test, P < 0.05, vs. GOLD II
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