Table 1 Baseline characteristics stratified by smoking history

Age—median years (IQR)

74 (61–84)

58 (50–69)

78 (66–85)

< 0.0001

78 (69–85)

< 0.0001

76.5 (61–85)

< 0.0001

Male—n (%)

347 (62%)

69 (65)

278 (61)

0.52

166 (67)

0.69

112 (54)

0.09

BMI, median (IQR)

26 (23–31)

26 (23–32)

26 (23–31)

0.87

26 (23–31)

0.66

26 (22–31)

0.86

FEV1 mean (std)^∫

1.76 (0.78)

2.11 (1.05)

1.65 (0.64)

0.048

1.64 (0.64)

0.049

1.67 (0.65)

0.09

FEV1 % pred mean (std)^∫

68.4 (24.5)

66.6 (23.3)

68.9 (24.9)

0.69

69.3 (24.2)

0.65

67.9 (27.5)

0.87

FVC mean (std) ^∫

2.54 (0.97)

3.07 (1.13)

2.37 (0.85)

< 0.01

2.39 (0.83)

0.004

2.32 (0.93)

0.03

FVC % pred mean (std)^∫

73.2 (20.9)

75.9 (20.5)

72.3 (21.0)

0.46

73.0 (19.0)

0.54

70.2 (26.6)

0.44

FEV1/FVC mean (std)^∫

68.6 (15.9)

67.3 (16.0)

69.0 (15.9)

0.65

69.1 (14.6)

0.64

68.7 (19.8)

0.79

Hospital acquired sepsis^#

52 (9.3%)

15 (14%)

37 (8.1%)

0.06

21 (8.4%)

0.11

16 (7.8%)

0.08

Charlson Score, median (IQR)

5 (4–7)

4 (2–5)

5 (4–7)

< 0.0001

6 (4–7)

< 0.0001

5 (3–7)

0.0005

MI, n (%)

151 (27)

19 (18)

132 (29)

0.002

93 (37)

0.0003

39 (19)

0.80

CHF, n (%)

137 (24)

14 (13)

123 (27)

0.003

75 (30)

0.0007

48 (23)

0.03

CVA, n (%)

75 (13)

6 (6)

69 (15)

< 0.01

38 (15)

0.01

31 (15)

0.01

Dementia, n (%)

64 (11)

3 (3)

61 (13)

< 0.01

34 (14)

0.002

27 (13)

0.003

COPD, n (%)

110 (20)

35 (33)

75 (17)

< 0.01

68 (27)

0.30

7 (3)

< 0.0001

DM, n (%)

161 (29)

27 (25)

134 (30)

0.39

72 (29)

0.48

62 (30)

0.37

Cirrhosis, n (%)

56 (10)

24 (22)

32 (7)

< 0.01

15 (6)

< 0.0001

17 (8)

0.0004

CKD, n (%)

55 (10)

5 (5)

50 (11)

0.05

33 (13)

17 (8)

 Pneumonia, n (%)

241 (43)

53 (50)

188 (41)

0.12

116 (47)

0.61

72 (35)

0.01

 Genitourinary

154 (27)

21 (20)

133 (29)

0.05

66 (27)

0.17

67 (32)

0.02

 Abdominal

108 (19)

31 (29)

77 (17)

< 0.01

42 (17)

0.01

35 (17)

0.01

 Soft tissue

39 (7)

2 (2)

37 (8)

0.02

23 (9)

0.01

14 (7)

0.06

 CNS

3 (1)

1 (1)

2 (0.4)

0.53

0 (0)

0.13

2 (1)

0.98

 Cardiovascular

9 (2)

2 (2)

7 (2)

0.81

2 (1)

0.38

5 (2)

0.75

 Blood stream

73 (13)

12 (11)

61 (13)

0.54

28 (11)

0.99

33 (16)

0.25

 CVC

10 (2)

0 (0)

10 (2)

0.12

4 (2)

0.19

6 (3)

0.07

 Other

0

0

0

–

0

–

0

–

 Unknown

16 (3)

2 (2)

14 (3)

0.50

6 (2)

0.75

8 (4)

0.34

Medical, n (%)

481 (86)

84 (79)

397 (87)

0.02

218 (88)

0.03

179 (87)

0.05

Surgical

81 (13)

23 (22)

58 (13)

31 (13)

27 (13)

Alcohol abuse, n (%)

64 (11)

37 (35)

27 (6)

< 0.01

19 (8)

< 0.0001

8 (4)

< 0.0001

Severe sepsis, n (%)

319 (57)

47 (44)

272 (60)

< 0.01

144 (58)

0.02

128 (62)

0.002

Septic shock, n (%)

243 (43)

60 (56)

183 (40)

105 (42)

78 (38)

Lactate—median (IQR)

2.1 (1.3–3.4)

2.1 (1.5–3.1)

2.05 (1.2–3.5)

0.53

2.0 (1.2–3.2)

0.53

2.1 (1.2–3.7)

0.61

SOFA score median (IQR)

6 (3–9)

7 (4–12)

5 (3–9)

< 0.01

5 (3–9)

0.001

5 (3–8)

< 0.0001

Respiratory^‡

median (IQR)

1 (0–2)

2 (0–3)

1 (0–2)

< 0.001

1 (0–3)

0.015

0 (0–2)

< 0.0001

72 h fluid balance—median L (IQR)

2.1 (0.2–4.35)

2.3 (0.01–5.9)

2.1 (0.26–4.1)

0.32

2.1 (0.01–4.1)

0.18

2.2 (0.5–4.1)

0.67

Stress steroids given—n (%)

38 (7)

9 (8)

29 (6)

0.45

17 (7)

0.60

12 (6)

0.38

Time to appropriate antibiotics after hypotension—minutes, median (IQR)

60 (− 60–159)

35 (− 117–120)

61 (− 60–165)

0.23

60 (− 76–165)

0.44

68.5 (− 22–170)

0.14

 Yes, n (%)

248 (44)

53(50)

195/454 (43)

0.17

107 (43)

0.17

88/205 (43)

0.26

 No, n (%)

50 (9)

5(5)

45/454 (10)

26 (10)

19/205 (9)

 Unknown, n (%)

263 (47)

49(46)

214/454 (47)

116 (47)

98/205 (48)