Table 1 Baseline characteristics of patients with AECOPD

Age (years)^†

71.1 ± 9.5

72.4 ± 8.6

0.223

72.7 ± 9.8

70.4 ± 8.5

0.023

71.5 ± 9.2

Sex, no. of exacerbations

Male^‡

144 (63.4%)

94 (81.7%)

0.001

105 (60.7%)

133 (78.7%)

 < 0.001

238 (69.6%)

Female^‡

83 (36.6%)

21 (18.3%)

68 (39.3%)

36 (21.3%)

104 (30.4%)

Smoking history, no. of exacerbations

Current smoker^‡

42 (18.5%)

21 (18.3%)

0.957

32 (18.5%)

31 (18.3%)

0.971

63 (18.4%)

Ex-smoker^‡

185 (81.5%)

94 (81.7%)

141 (81.5)

138 (81.7%)

279 (81.6%)

Pack-year history^†

41.1 ± 16.8

41.8 ± 17.9

0.446

40.9 ± 16.5

41.7 ± 17.8

0.987

Comorbidities, no. of exacerbations

Hypertension^‡

111 (48.9%)

53 (46.1%)

0.623

85 (49.1%)

79 (46.7%)

0.659

164 (48.0%)

Diabetes^‡

54 (23.8%)

25 (21.7%)

0.671

43 (24.9%)

36 (21.3%)

0.436

49 (23.1%)

Previous TB history^‡

58 (25.6%)

43 (37.4%)

0.023

35 (20.2%)

66 (39.1%)

 < 0.001

101 (29.5%)

Coronary artery disease^‡

37 (16.3%)

17 (14.8%)

0.716

32 (18.5%)

22 (13.0%)

0.165

54 (15.8%)

Cerebrovascular accident^‡

6 (2.6%)

9 (7.8%)

0.027

5 (2.9%)

10 (5.9%)

0.172

15 (4.4%)

Inhaler use before admission

LABAs^‡

2 (0.9%)

1 (0.9%)

0.015

2 (1.2%)

1 (0.6%)

 < 0.001

3 (0.9%)

LAMAs^‡

24 (10.6%)

14 (12.2%)

27 (15.6%)

11 (6.5%)

38 (11.1%)

LABAs + LAMAs^‡

36 (15.9%)

16 (13.9%)

24 (13.9%)

28 (16.6%)

52 (15.2%)

ICS/LABAs^‡

25 (11.0%)

7 (6.1%)

21 (12.1%)

11 (6.5%)

32 (9.4%)

Triple therapy^‡

53 (23.3%)

47 (40.9%)

32 (18.5%)

68 (40.2%)

100 (29.2%)

None^‡

87 (38.3%)

30 (26.1%)

67 (38.7%)

50 (29.6%)

117 (34.2%)

Oral medication before admission

Oral β2 adrenoreceptor agonist^‡

8 (3.5%)

19 (16.5%)

 < 0.001

9 (5.2%)

18 (10.7%)

0.062

27 (7.9%)

Roflumilast^‡

7 (3.1%)

10 (8.7%)

0.024

1 (0.6%)

16 (9.5%)

 < 0.001

17 (5.0%)

Mucolytic agent^‡

92 (40.5%)

65 (56.5%)

0.005

68 (43.3%)

89 (52.7%)

0.013

157 (45.9%)

Oral steroids^‡

6 (2.6%)

2 (1.7%)

0.722

2 (1.2%)

6 (3.6%)

0.170

8 (2.3%)

Oral antibiotics^‡

7 (3.1%)

4 (3.5%)

1.000

3 (1.7%)

8 (4.7%)

0.116

11 (3.2%)

Baseline spirometry

FEV₁ (liters)^†

1.5 ± 0.5

1.1 ± 0.4

 < 0.001

1.6 ± 0.5

1.0 ± 0.3

 < 0.001

1.3 ± 0.5

FEV₁ (% of predicted value)^†

59.9 ± 18.1

42.1 ± 16.0

 < 0.001

69.5 ± 13.6

38.0 ± 8.1

 < 0.001

54.0 ± 19.3

D_LCO (liters)^†

12.5 ± 5.0

6.6 ± 2.2

 < 0.001

11.9 ± 5.3

8.9 ± 4.1

 < 0.001

10.6 ± 5.1

D_LCO (% of predicted value)^†

73.5 ± 16.4

38.7 ± 8.8

 < 0.001

71.4 ± 20.4

52.0 ± 18.7

 < 0.001

61.8 ± 21.8