Table 1 Demographic characteristic, laboratory results, symptoms, physical examinations

Age(years)

83.9 ± 3.3

72.25 ± 4.18

50.53 ± 11.25

Female n (%)

354 (58.1%)

1313 (48%)

2272 (55.5%)

< 0.001

BMI

23.1 ± 3.4

23.9 ± 3.6

24.03 ± 3.6

< 0.001

Major comorbidity, n (%)

 Cardiovascular disease n (%)

436 (71.6%)

1716 (62.9%)

1291 (31.6%)

< 0.001

  Hypertension n (%)

352 (57.8%)

1372 (50.3%)

946 (23.1%)

< 0.001

  Coronary heart disease n (%)

185 (30.4%)

567 (20.8%)

252 (6.2%)

< 0.001

  Rheumatic heart disease n (%)

3 (0.5%)

25 (0.9%)

20 (0.5%)

0.087

  Cardiomyopathy n (%)

4 (0.7%)

15 (0.5%)

26 (0.6%)

0.896

  Heart failure n (%)

65 (10.7%)

191 (7.0%)

106 (2.6%)

< 0.001

 Respiratory disease n (%)

265 (43.5%)

876 (32.1%)

888 (21.7%)

< 0.001

  Chronic obstructive pulmonary disease n (%)

106 (17.4%)

349 (12.8%)

143 (3.5%)

< 0.001

  Pulmonary infection n (%)

114 (18.7%)

346 (12.7%)

400 (9.8%)

< 0.001

  Pulmonary Tuberculosis n (%)

44 (7.2%)

99 (3.6%)

83 (2.0%)

< 0.001

  Asthma n (%)

11 (1.8%)

36 (1.3%)

49 (1.2%)

0.464

  Interstitial lung disease n (%)

25 (4.1%)

69 (2.5%)

36 (0.9%)

< 0.001

  Cor pulmonale n (%)

35 (5.7%)

86 (8.2%)

68 (1.7%)

< 0.001

  Bronchiectasis n (%)

14 (2.3%)

35 (1.3%)

42 (1.0%)

0.026

  Lung cancer n (%)

14 (2.3%)

99 (3.6%)

160 (3.9%)

0.137

 Hyperlipidemia n (%)

35 (5.7%)

151 (5.5%)

174 (4.3%)

0.032

 Diabetes n (%)

111 (18.3%)

383 (14.1%)

301 (7.4%)

< 0.001

 Neurological diseases n (%)

150 (24.8%)

449 (16.5%)

337 (8.3%)

< 0.001

  Ischemic stroke n (%)

116 (19.2%)

336 (12.4%)

192 (4.7%)

< 0.001

  Hemorrhagic stroke n (%)

20 (3.3%)

48 (1.8%)

71 (1.7%)

0.028

 Malignancy n (%)

71 (11.7%)

354 (13%)

476 (11.7%)

0.224

 Varicose n (%)

35 (5.7%)

207 (7.6%)

299 (7.3%)

0.278

 DVT

221 (37%)

998 (36.9%)

1729 (42.7%)

< 0.001

 Liver and kidney disease n (%)

24 (4.0%)

92 (3.4%)

194 (4.8%)

0.021

  Liver cirrhosis n (%)

2 (0.3%)

8 (0.3%)

18 (0.4%)

0.624

  Chronic hepatitis n (%)

6 (1.0%)

34 (1.2%)

87 (2.1%)

0.009

  Chronic nephritis n (%)

11 (1.8%)

26 (1.0%)

33 (0.8%)

0.056

  Nephrotic syndrome n (%)

4 (0.7%)

26 (1.0%)

55 (1.3%)

0.171

 Diuretics n (%)

2 (0.3%)

23 (0.9%)

40 (1.0%)

0.262

 Central venous catheterization

0 (0.0%)

0 (0.0%)

14 (0.4%)

0.005

 Smoking n (%)

195 (36.7%)

795 (35.3%)

1269 (37.9%)

0.284

 Surgery, trauma, immobilization n (%)

474 (78.0%)

2357 (86.2%)

3567 (87.1%)

< 0.001

Laboratory examination

 Platelet count (× 109/L)

195.1 ± 75.2

201.5 ± 77.1

218.9 ± 87.2

< 0.001

 Hemoglobin (g/L)

123.3 ± 20.7

126.5 ± 20.0

129.9 ± 22.4

< 0.001

 White blood cell > 10*10⁹/L

125 (20.8%)

595 (22.1%)

1215 (30.2%)

< 0.001

 PaO2 < 60 mmHg n (%)

114 (21.3%)

578 (24%)

623 (18%)

< 0.001

 eGFR < 60 mL/min/1.73m2 n (%)

209 (35.9%)

505 (19.4%)

242 (6.2%)

< 0.001

 Elevated BNP or NT-proBNP n (%)

385 (63.2%)

1638 (59.9%)

2296 (56.1%)

< 0.001

 Elevated CTN n (%)

357 (58.6%)

1549 (56.7%)

2241 (54.7%)

0.096

Symptoms and signs

 Cough n (%)

295 (48.5%)

1172 (43%)

1641 (40.2%)

< 0.001

 Sputum n (%)

258 (42.5%)

946 (34.7%)

1189 (29.1%)

< 0.001

 Dyspnea n (%)

385 (63.3%)

1862 (68.3%)

2746 (67.2%)

0.062

 Chest pain n (%)

158 (26.0%)

895 (32.8%)

1798 (44.0%)

< 0.001

 Hemoptysis n (%)

34 (5.6%)

223 (8.2%)

748 (18.3%)

< 0.001

 Palpitation n (%)

62 (10.2%)

378 (13.9%)

560 (13.7%)

0.047

 Syncope n (%)

50 (8.2%)

274 (10.0%)

453 (11.1%)

0.065

Physical examinations

 Temperature > 37.3◦C n (%)

45 (7.4%)

224 (8.2%)

531 (13.0%)

< 0.001

 Pulse > 110/min n (%)

42 (7.0%)

227 (8.4%)

469 (11.5%)

< 0.001

 SBP < 100 mmHg n (%)

12 (2.0%)

107 (3.9%)

249 (6.1%)

< 0.001

 DBP < 60 mmHg n (%)

30 (5.0%)

103 (3.8%)

153 (3.8%)

0.351

 Respiratory rate > 20/min n (%)

189 (31.2%)

959 (35.2%)

1530 ( 37.5%)

0.005

 Cyanosis n (%)

86 (14.3%)

431 (15.8%)

527 (12.9%)

0.003

 Moist crackle n (%)

213 (35.3%)

784 (28.8%)

835 (20.5%)

< 0.001

 Wheezing n (%)

85 (14.1%)

242 (8.9%)

184 (4.5%)

< 0.001

 Vascular murmur n (%)

3 (0.5%)

6 (0.2%)

19 (0.5%)

0.240

 Pleural rub n (%)

1 (0.2%)

15 (0.6%)

29 (0.7%)

0.247

 Jugular venous distention n (%)

48 (8.0%)

189 (6.9%)

231 (5.7%)

0.024

 Cardiomegaly n (%)

57 (9.5%)

223 (8.2%)

256 (6.3%)

0.001

 Tricuspid area murmur n (%)

14 (2.3%)

93 (3.4%)

147 (3.6%)

0.266

 P2 increase n (%)

81 (13.4%)

367 (13.5%)

700 (17.2%)

< 0.001

 Heart beats under the xiphoid process n (%)

8 (1.3%)

40 (1.5%)

82 (2.0%)

0.172

 Abdominal signs n (%)

17 (2.8%)

112 (4.1%)

155 (3.8%)

0.326

 Limb sighs n (%)

258 (42.6%)

1030 (37.9%)

1557 (38.4%)

0.093

 Leg edema n (%)

243 (40.2%)

913 (33.6%)

1355 (33.4%)

0.004

 Arm edema n (%)

5 (0.8%)

31 (1.1%)

44 (1.1%)

808

 Leg varicose n (%)

32 (5.3%)

176 (6.5%)

267 (6.6%)

0.482

 Homan sigh n (%)

7 (1.2%)

25 (0.9%)

97 (2.4%)

< 0.001

 Gastrocnemius tenderness n (%)

5 (0.8%)

58 (2.1%)

187 (4.6%)

< 0.001