Table 1 Comparison of COVID-positive inpatients by the period of admission

N

7112

860

1556

9528

Age, years

57.7 ± 19.3

58.8 ± 19.3

61.0 ± 19.9

< 0.0001

58.3 ± 19.4

Male sex

3630 (51.0%)

458 (53.3%)

783 (50.3%)

0.37

4871 (51.1%)

BMI

30.0 ± 7.4

29.9 ± 7.8

29.0 ± 7.9

< 0.0001

29.8 ± 7.5

Obesity (BMI > 30)

2935 (43.4%)

359 (43.3%)

559 (38.0%)

0.0007

3853 (42.5%)

Morbid obesity (BMI > 40)

573 (8.5%)

74 (8.9%)

126 (8.6%)

0.90

773 (8.5%)

Comorbidities

 Charlson’s comorbidity index (CCI)

3.78 ± 3.57

4.25 ± 3.85

5.05 ± 3.90

< 0.0001

4.03 ± 3.68

 Myocardial infarction

606 (8.5%)

115 (13.4%)

226 (14.5%)

< 0.0001

947 (9.9%)

 Congestive heart failure

1058 (14.9%)

180 (20.9%)

390 (25.1%)

< 0.0001

1628 (17.1%)

 Peripheral vascular disease

749 (10.5%)

112 (13.0%)

254 (16.3%)

< 0.0001

1115 (11.7%)

 Cerebrovascular disease

894 (12.6%)

139 (16.2%)

279 (17.9%)

< 0.0001

1312 (13.8%)

 Dementia

882 (12.4%)

106 (12.3%)

250 (16.1%)

0.0004

1238 (13.0%)

 Chronic pulmonary disease

1514 (21.3%)

214 (24.9%)

458 (29.4%)

< 0.0001

2186 (22.9%)

 Connective tissue/rheumatic disease

203 (2.9%)

39 (4.5%)

77 (4.9%)

< 0.0001

319 (3.3%)

 Peptic ulcer disease

197 (2.8%)

27 (3.1%)

72 (4.6%)

0.0007

296 (3.1%)

 Mild liver disease

675 (9.5%)

96 (11.2%)

173 (11.1%)

0.07

944 (9.9%)

 Diabetes without complications

1542 (21.7%)

139 (16.2%)

217 (13.9%)

< 0.0001

1898 (19.9%)

 Diabetes with complications

1104 (15.5%)

172 (20.0%)

361 (23.2%)

< 0.0001

1637 (17.2%)

 Paraplegia and hemiplegia

228 (3.2%)

34 (4.0%)

68 (4.4%)

0.05

330 (3.5%)

 Renal disease

1399 (19.7%)

211 (24.5%)

490 (31.5%)

< 0.0001

2100 (22.0%)

 Non-metastatic cancer

355 (5.0%)

60 (7.0%)

130 (8.4%)

< 0.0001

545 (5.7%)

 Moderate/severe liver disease

89 (1.3%)

3 (0.3%)

34 (2.2%)

0.0005

126 (1.3%)

 Metastatic carcinoma

123 (1.7%)

17 (2.0%)

55 (3.5%)

< 0.0001

195 (2.0%)

 AIDS

24 (0.3%)

1 (0.1%)

5 (0.3%)

0.55

30 (0.3%)

 Elixhauser’s comorbidity index (ECI)

10.4 ± 11.5

12.7 ± 12.3

14.2 ± 12.7

< 0.0001

11.2 ± 11.9

COVID-related findings

 O₂ saturation at admission ≤ 90%

1610 (22.8%)

182 (21.2%)

260 (16.8%)

< 0.0001

2052 (21.7%)

 COVID-19 pneumonia

2743 (38.6%)

655 (76.2%)

918 (59.0%)

< 0.0001

4316 (45.3%)

 Coagulopathy

832 (11.7%)

146 (17.0%)

217 (13.9%)

< 0.0001

1195 (12.5%)

 Vaccinated (at least 1 dose)

63 (1.3%)

372 (45.5%)

881 (60.6%)

< 0.0001

1316 (18.7%)

Inpatient resource utilization

 LOS, days

9.18 ± 10.68

9.70 ± 11.70

7.14 ± 6.23

< 0.0001

8.90 ± 10.22

 Admitted to ICU

2042 (28.7%)

184 (21.4%)

239 (15.4%)

< 0.0001

2465 (25.9%)

 LOS in ICU, days

9.75 ± 11.70

9.35 ± 16.33

5.15 ± 6.29

< 0.0001

9.27 ± 11.78

 Invasive mechanical ventilation

838 (11.8%)

115 (13.4%)

118 (7.6%)

< 0.0001

1071 (11.2%)

 ECMO

59 (0.8%)

13 (1.5%)

4 (0.3%)

0.0034

76 (0.8%)

Disposition

 Short-term care facility

63 (0.9%)

17 (2.0%)

15 (1.0%)

0.0097

95 (1.0%)

 Long-term care facility

729 (10.3%)

102 (11.9%)

166 (10.7%)

0.33

997 (10.5%)

 Home (including home healthcare)

5373 (75.5%)

618 (71.9%)

1189 (76.4%)

0.0344

7180 (75.4%)

 Hospice (including home hospice)

158 (2.2%)

42 (4.9%)

65 (4.2%)

< 0.0001

265 (2.8%)

 Expired

789 (11.1%)

81 (9.4%)

121 (7.8%)

0.0003

991 (10.4%)