Table 5 Patient characteristics in the groups included into or excluded from study

Age (years), mean (sd)

78.3 (10.7)

78.4 (9.5)

1.0

Sex (female), n (%)

6415 (19.2)

2355 (18.7)

1.3

Pre-admission within180 day, n (%)

7997 (24.0)

2853 (22.7)

3.1

Japan Coma Scale, n (%)

20.0

 Alert

22972 (68.9)

9485 (75.4)

 Dull

6234 (18.7)

2198 (17.5)

 Somnolence

2006 (6.0)

529 (4.2)

 Coma

2114 (6.3)

360 (2.9)

 Missing

1 (0.0)

0 (0.0)

Body mass index, n (%)

13.1

  < 18.5

11733 (35.2)

4372 (34.8)

 18.5–22.9

10081 (30.2)

4179 (33.2)

 23.0–24.9

2440 (7.3)

1041 (8.3)

 25.0–29.9

1926 (5.8)

817 (6.5)

  ≥ 30

349 (1.0)

170 (1.4)

 Missing

6798 (20.4)

1993 (15.9)

Smoking index, mean (sd)

4218 (596790)

719 (1577)

0.8

Barthel index, n (%)

15.5

 0

13601 (40.8)

4335 (34.5)

 5–9

2928 (8.8)

1422 (11.3)

 10–14

3565 (10.7)

1648 (13.1)

 15–19

1882 (5.6)

741 (5.9)

 20

4910 (14.7)

1775 (14.1)

 Missing

6441 (19.3)

2651 (21.1)

Hugh-Jones dyspnoea scale score, n (%)

19.6

 0

7076 (21.2)

1918 (15.3)

 1

1494 (4.5)

513 (4.1)

 2

2412 (7.2)

1009 (8.0)

 3

2775 (8.3)

1179 (9.4)

 4

5624 (16.9)

2823 (22.5)

 5

11574 (34.7)

4331 (34.4)

 Missing

2372 (7.1)

799 (6.4)

Charlson comorbidity index, n (%)

6.8

 0–1

20712 (62.1)

7879 (62.7)

 2–3

10494 (31.5)

4086 (32.5)

  ≥ 4

2121 (6.4)

607 (4.8)

Intensive care unit admission, n (%)

2093 (6.3)

1088 (8.7)

9.2

Oxygen intake at admission, n (%)

22151 (66.5)

8787 (69.9)

7.4

Intubation at admission, n (%)

1547 (4.6)

478 (3.8)

4.2

Steroid dose (mg), mean (sd)

180.6 (611.3)

210.6 (620.9)

4.9

Hospital volume, mean (sd)

209.4 (139.4)

221.1 (131.9)

8.6

Population density of patient living area ≤ 249 persons/km², n (%)

27697 (83.1)

10595 (84.3)

3.2

 Missing

169 (0.5)

64 (0.5)

Distance between patient residence and hospital (km), mean (SD)

6.0 (19.6)

7.1 (26.0)

4.6