Table 2 Characteristics between in-hospital mortality and non-in-hospital mortality among elderly CAP patients

Age, years, Mean ± SD

78.16 ± 7.91

77.94 ± 7.92

78.82 ± 7.87

t = − 0.96

Gender, n (%)

χ² = 1.245

 Female

186 (46.27)

145 (47.85)

41 (41.41)

 Male

216 (53.73)

158 (52.15)

58 (58.59)

Marital status, n (%)

Fisher

 Divorced

19 (4.73)

17 (5.61)

2 (2.02)

 Married

193 (48.01)

143 (47.19)

50 (50.51)

 Separate

2 (0.50)

1 (0.33)

1 (1.01)

 Single

72 (17.91)

54 (17.82)

18 (18.18)

 Widowed

116 (28.86)

88 (29.04)

28 (28.28)

Ethnicity, n (%)

χ² = 4.822

 Asian

17 (4.23)

12 (3.96)

5 (5.05)

 Black

43 (10.70)

32 (10.56)

11 (11.11)

 Hispanic

8 (1.99)

8 (2.64)

0 (0.00)

 Other

5 (1.24)

4 (1.32)

1 (1.01)

 White

329 (81.84)

247 (81.52)

82 (82.83)

Liver cirrhosis, n (%)

χ² = 0.001

 No

394 (98.01)

297 (98.02)

97 (97.98)

 Yes

8 (1.99)

6 (1.98)

2 (2.02)

CHF, n (%)

χ² = 1.750

 No

188 (46.77)

136 (44.88)

52 (52.53)

 Yes

214 (53.23)

167 (55.12)

47 (47.47)

Renal failure, n (%)

χ² = 2.936

 No

176 (43.78)

140 (46.20)

36 (36.36)

 Yes

226 (56.22)

163 (53.80)

63 (63.64)

COPD, n (%)

χ² = 2.240

 No

311 (77.36)

229 (75.58)

82 (82.83)

 Yes

91 (22.64)

74 (24.42)

17 (17.17)

Septic shock, n (%)

χ² = 8.528

 No

328 (81.59)

257 (84.82)

71 (71.72)

 Yes

74 (18.41)

46 (15.18)

28 (28.28)

Effusion, n (%)

χ² = 0.023

 No

351 (87.31)

265 (87.46)

86 (86.87)

 Yes

51 (12.69)

38 (12.54)

13 (13.13)

Emphysema, n (%)

χ² = 0.698

 No

384 (95.52)

288 (95.05)

96 (96.97)

 Yes

18 (4.48)

15 (4.95)

3 (3.03)

Pneumothorax, n (%)

χ² = 0.461

 No

395 (98.26)

297 (98.02)

98 (98.99)

 Yes

7 (1.74)

6 (1.98)

1 (1.01)

Lung cancer, n (%)

χ² = 0.088

 No

380 (94.53)

287 (94.72)

93 (93.94)

 Yes

22 (5.47)

16 (5.28)

6 (6.06)

Heart disease, n (%)

χ² = 0.426

 No

341 (84.83)

255 (84.16)

86 (86.87)

 Yes

61 (15.17)

48 (15.84)

13 (13.13)

DM, n (%)

χ² = 3.823

 No

308 (76.62)

225 (74.26)

83 (83.84)

 Yes

94 (23.38)

78 (25.74)

16 (16.16)

Respiratory failure, n (%)

χ² = 6.901

 No

163 (40.55)

134 (44.22)

29 (29.29)

 Yes

239 (59.45)

169 (55.78)

70 (70.71)

Hyperlipidemia, n (%)

χ² = 2.803

 No

256 (63.68)

186 (61.39)

70 (70.71)

 Yes

146 (36.32)

117 (38.61)

29 (29.29)

Malignant cancer, n (%)

χ² = 2.055

 No

256 (63.68)

187 (61.72)

69 (69.70)

 Yes

146 (36.32)

116 (38.28)

30 (30.30)

AF, n (%)

χ² = 0.829

 No

231 (57.46)

178 (58.75)

53 (53.54)

 Yes

171 (42.54)

125 (41.25)

46 (46.46)

Heart rate, beats/min, Mean ± SD

96.79 ± 21.01

96.74 ± 20.98

96.92 ± 21.21

t = − 0.07

Respiratory rate, times/min, Mean ± SD

22.71 ± 6.84

22.28 ± 6.87

24.03 ± 6.61

t = − 2.22

Temperature, °C, Mean ± SD

36.80 ± 1.01

36.85 ± 1.02

36.65 ± 0.99

t = 1.74

SOFA, M (Q₁, Q₃)

5.00 (3.00, 7.00)

4.00 (2.00, 7.00)

7.00 (4.00, 9.00)

Z = 5.173

SAPSII, Mean ± SD

44.58 ± 13.34

41.98 ± 11.77

52.57 ± 14.70

t = − 6.52

SOAR, M (Q₁, Q₃)

2.00 (1.00, 2.00)

2.00 (1.00, 2.00)

2.00 (1.00, 2.00)

Z = 3.563

PSI, Mean ± SD

136.48 ± 26.49

135.61 ± 27.65

139.13 ± 22.51

t = − 1.27

CURB-65, Mean ± SD

2.52 ± 0.80

2.41 ± 0.78

2.85 ± 0.77

t = − 4.84

GCS, M (Q₁, Q₃)

14.00 (8.00, 15.00)

14.00 (9.00, 15.00)

10.00 (6.00, 15.00)

Z = − 3.637

INR, M (Q₁, Q₃)

1.30 (1.10, 1.60)

1.20 (1.10, 1.50)

1.40 (1.20, 1.80)

Z = 3.060

Elixhauser comorbidity score, M (Q₁, Q₃)

20.00 (12.00, 29.00)

20.00 (12.00, 28.00)

23.00 (11.00, 33.00)

Z = 1.640

Streptococcus pneumoniae, n (%)

χ² = 0.459

 No

390 (97.01)

293 (96.70)

97 (97.98)

 Yes

12 (2.99)

10 (3.30)

2 (2.02)

Klebsiella pneumoniae, n (%)

χ² = 1.356

 No

379 (94.28)

288 (95.05)

91 (91.92)

 Yes

23 (5.72)

15 (4.95)

8 (8.08)

Legionella pneumophila, n (%)

χ² = 1.356

 No

402 (100.00)

303 (100.00)

99 (100.00)

Other Streptococcus, n (%)

χ² = 0.142

 No

383 (95.27)

288 (95.05)

95 (95.96)

 Yes

19 (4.73)

15 (4.95)

4 (4.04)

Virus, n (%)

χ² = 0.018

 No

389 (96.77)

293 (96.70)

96 (96.97)

 Yes

13 (3.23)

10 (3.30)

3 (3.03)

Other bacteria, n (%)

χ² = 10.753

 No

291 (72.39)

232 (76.57)

59 (59.60)

 Yes

111 (27.61)

71 (23.43)

40 (40.40)

Yeast, n (%)

χ² = 7.565

 No

265 (65.92)

211 (69.64)

54 (54.55)

 Yes

137 (34.08)

92 (30.36)

45 (45.45)

Staphylococcus, n (%)

χ² = 0.135

 No

274 (68.16)

208 (68.65)

66 (66.67)

 Yes

128 (31.84)

95 (31.35)

33 (33.33)

EColi, n (%)

χ² = 0.025

 No

371 (92.29)

280 (92.41)

91 (91.92)

 Yes

31 (7.71)

23 (7.59)

8 (8.08)

Candida, n (%)

χ² = 0.198

 No

378 (94.03)

284 (93.73)

94 (94.95)

 Yes

24 (5.97)

19 (6.27)

5 (5.05)

Acinetobacter, n (%)

Fisher

 No

398 (99.00)

300 (99.01)

98 (98.99)

 Yes

4 (1.00)

3 (0.99)

1 (1.01)

Clostridium, n (%)

χ² = 0.260

 No

389 (96.77)

294 (97.03)

95 (95.96)

 Yes

13 (3.23)

9 (2.97)

4 (4.04)

Citrobacter, n (%)

Fisher

 No

401 (99.75)

302 (99.67)

99 (100.00)

 Yes

1 (0.25)

1 (0.33)

0 (0.00)

Enterococcus, n (%)

χ² = 0.003

 No

366 (91.04)

276 (91.09)

90 (90.91)

 Yes

36 (8.96)

27 (8.91)

9 (9.09)

PCP, n (%)

χ² = 1.134

 No

400 (99.50)

301 (99.34)

99 (100.00)

 Yes

2 (0.50)

2 (0.66)

0 (0.00)

Fungus, n (%)

Fisher

 No

400 (99.50)

302 (99.67)

98 (98.99)

 Yes

2 (0.50)

1 (0.33)

1 (1.01)

MCV, Mean ± SD

91.01 ± 7.05

90.59 ± 7.06

92.28 ± 6.90

t = − 2.08

Hematocrit, %, Mean ± SD

35.00 ± 6.14

35.22 ± 6.37

34.34 ± 5.34

t = 1.36

RBC, m/uL, Mean ± SD

3.87 ± 0.71

3.91 ± 0.73

3.74 ± 0.62

t = 2.28

Potassium, mEq/L, Mean ± SD

4.51 ± 0.93

4.49 ± 0.91

4.59 ± 0.98

t = − 0.91

Phosphate, mg/dL, M (Q₁, Q₃)

3.40 (2.80,4.20)

3.30 (2.80,4.10)

3.70 (3.00,4.50)

Z = 2.480

Calcium, mg/dL, Mean ± SD

8.42 ± 0.95

8.43 ± 0.96

8.38 ± 0.93

t = 0.45

Magnesium, Mean ± SD

1.93 ± 0.37

1.93 ± 0.36

1.91 ± 0.40

t = 0.42

Lactate, mmol/L, M (Q₁, Q₃)

2.00 (1.50, 2.90)

1.90 (1.50, 2.80)

2.20 (1.50, 3.70)

Z = 1.886

Creatine kinase, IU/L, M (Q₁, Q₃)

80.50 (40.00, 181.00)

80.00 (39.00, 183.00)

82.00 (40.00, 167.00)

Z = 0.237

pH, Mean ± SD

7.37 ± 0.11

7.38 ± 0.10

7.33 ± 0.14

t = 2.64

SpO2, Mean ± SD

95.94 ± 5.57

95.90 ± 6.00

96.07 ± 4.01

t = − 0.32

PO2, M (Q₁, Q₃)

85.50 (63.00,129.00)

84.00 (63.00, 128.00)

89.00 (65.00, 136.00)

Z = 0.343

PCO2, M (Q₁, Q₃)

42.00 (34.00, 51.00)

42.00 (35.00, 51.00)

39.00 (33.00, 52.00)

Z = − 0.757

Fio2, M (Q₁, Q₃)

35.00 (1.00, 70.00)

35.00 (1.00, 60.00)

40.00 (1.00, 100.00)

Z = 1.280

Invasive ventilation, n (%)

χ² = 23.105

 No

218 (54.23)

185 (61.06)

33 (33.33)

 Yes

184 (45.77)

118 (38.94)

66 (66.67)

Ventilation, n (%)

χ² = 18.792

 No

177 (44.03)

152 (50.17)

25 (25.25)

 Yes

225 (55.97)

151 (49.83)

74 (74.75)

Vesopressor, n (%)

χ² = 29.794

 No

376 (93.53)

295 (97.36)

81 (81.82)

 Yes

26 (6.47)

8 (2.64)

18 (18.18)

NLR, M (Q₁, Q₃)

9.92 (5.97, 19.98)

9.40 (6.04, 19.60)

11.20 (5.71, 21.28)

Z = 0.789

PLR, M (Q₁, Q₃)

2.75 (1.69, 4.74)

2.72 (1.68, 4.70)

3.03 (1.78, 4.91)

Z = 0.458

PNI, Mean ± SD

31.65 ± 8.90

32.33 ± 9.33

29.59 ± 7.12

t = 3.06

Anion gap, Mean ± SD

16.39 ± 3.86

16.33 ± 3.92

16.58 ± 3.69

t = − 0.55

HPR, M (Q₁, Q₃)

0.46 (0.32, 0.63)

0.46 (0.32, 0.63)

0.48 (0.35, 0.70)

Z = 1.571

RDW/BUN, Mean ± SD

5.32 ± 1.59

5.16 ± 1.52

5.79 ± 1.74

t = − 3.47

dNLR, Mean ± SD

− 1.01 ± 0.09

− 1.01 ± 0.06

− 1.02 ± 0.15

t = 0.26

BUN/ALB, M (Q₁, Q₃)

9.63 (6.21, 14.40)

9.05 (5.71, 14.00)

11.00 (7.35, 16.18)

Z = 2.891

SII, M (Q₁, Q₃)

24.74 (13.09, 44.68)

26.36 (13.61, 45.36)

21.64 (11.00, 42.32)

Z = − 1.723

LOS, M (Q₁, Q₃)

3.25 (1.72, 7.43)

3.06 (1.66, 7.01)

4.13 (1.95, 9.05)

Z = 1.632