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Table 1 Characteristics of the development and test cohorts

From: Predicting clinical outcomes among hospitalized COVID-19 patients using both local and published models

Characteristics Development cohort (N = 309) Test cohort (N = 207) P
Missing Data Missing Data
Outcome variables(N, (%))        
Mortality 38 (12.3)   21 (10.1)   0.45
Criticality 80 (25.9)   46 (22.2)   0.34
Demographics        
Age (Mean, (SD)) 56.5 (16.0)   53.3 (18.5)   0.008*
Female (%) 49.8    48.3    0.73
Race (N (%))    1%    1.4% 0.22
African American 152 (49.2)   86 (41.5)   
Hispanic 37 (12)   25 (12.1)   
Other, Non- Hispanic 94 (30.4)   82 (39.6)   
White 23 (7.4)   11 (5.3)   
Vital signs on admission (mean (SD))        
Systolic blood pressure 135 (25)   134 (24.7)   0.80
Diastolic blood pressure 78.3 (15)   77.9 (14.3)   0.92
Hearth rate 102 (21)   97.1 (20.1)   0.70
Respiratory rate 23.6 (6.9)   22.7 (6.6)   0.52
Temperature 37.5 (1.1)   37.2 (1.0)   0.095
Oxygen saturation 93.4 (7.5)   97.7 (62.4)   0.16
Clinical and radiological features        
BMI, mean (SD) 32.3 (10.5)   32.0 (9.6)   0.56
GCS, mean (SD) 14.9 (0.8) 0% 14.8 (1.2) 1% 0.28
Dyspnea (N (%)) 125 (40.5)   90 (43.5)   0.49
Coma (N (%)) 3 (1)   1 (0.5)   0.54
Pregnant (N (%)) 10 (3.2)   14 (6.8)   0.062
Abnormal chest X-ray (N (%)) 228 (75) 1.9% 136 (74) 10.6%** 0.67
Laboratory findings (mean, (SD)        
White blood cells 6.8 (3.1) 0% 7.7 (3.9) 1% 0.001*
Neutrophiles 5.2 (3.6) 0% 5.6 (3.7) 3.4% 0.038*
Lymphocytes 1.1 (0.7) 0% 1.3 (1) 3.4% 0.024*
Hemoglobin 13.0 (2.2) 0% 12.7 (2.3) 1% 0.57
Hematocrit 39.4 (6.3) 0% 37.9 (6.8) 1% 0.36
RDW 14.9 (2) 0% 15.1 (2.2) 1% 0.68
Platelets 215 (91) 0% 236 (105) 1% 0.15
Creatinine 1.8 (3) 0% 1.9 (2.6) 2.4% 0.47
Lactic acid 1.6 (1.6) 23.3% 1.8 (1.9) 30.4% 0.11
Lactate dehydrogenase 353 (227) 16.5% 386 (521) 27.5%** 0.14
Pro-calcitonin 1.4 (6.7) 16.8% 2.2 (10.4) 32.9%** 0.12
Troponin I 0.11 (0.8) 32.4% 0.04 (0.1) 31.4% 0.076
B-type natriuretic peptide 527 (1939) 57% 369 (664) 63.8% 0.10
Albumin 3.7 (0.5) 3.9% 3.6 (0.6) 7.2% 0.009*
ALT 38.8 (44.4) 3.9% 37.8 (49.9) 7.2% 0.88
AST 48.2 (58.3) 3.9% 52.3 (81.3) 7.2% 0.20
Total bilirubin 0.7 (0.9) 3.9% 0.8 (0.7) 7.2% 0.76
Direct bilirubin 0.2 (0.5) 3.9% 0.2 (0.3) 7.2% 0.57
Creatine kinase 281 (471) 63.8% 3071+ (22,782) 67.6% 0.012*
C-reactive protein 101 (84) 15.5% 98.6 (86.7) 19.8% 0.46
Interleukin 6 24.9 (33.9) 75.1% 28.1 (40.2) 87.9%** 0.17
D-dimer 1.9 (2.6) 40.8% 2.2 (3) 27.5%** 0.46
Ferritin 884 (1562) 7.1% 930 (1360) 17.4%** 0.45
Medical condition        
Hypertension 178 (57.6)   111 (53.6)   0.37
Heart disease 94 (30)   56 (27)   0.41
Stroke 23 (7.4)   11 (5.3)   0.34
Diabetes 161 (52.1)   96 (46)   0.20
Asthma 65 (21)   45 (22)   0.85
COPD 24 (7.8)   13 (6.3)   0.52
Chronic kidney disease 52 (17)   38 (18)   0.65
End-stage renal disease 30 (9.7)   24 (12)   0.49
Cancer 33 (11)   23 (11)   0.88
Transplant 1 (0.3)   1 (0.5)   0.78
Human immunodeficiency virus 7 (2.3)   1 (0.5)   0.11
Immunosuppression 2 (0.6)   9 (4.3)   0.004*
Sickle cell disease 6 (2)   6 (2.9)   0.48
Nicotine use 34 (11)   32 (16)   0.14
Alcohol use 59 (19)   45 (22)   0.46
Substance use 16 (5)   11 (5.3)   0.95
Variables needed for external models only        
Blood urea nitrogen, mean (SD)     23.5 (20.7) 1.9%  
eGFR, mean (SD)     70.9 (40.6) 2.4%  
Partial thromboplastin time, mean (SD)     34.4 (6.5) 42.5%  
  1. ALT, alanine aminotransferase; AST, aspartate aminotransferase; BMI, body mass index; COPD, chronic obstructive pulmonary disease; eGFR, estimated glomerular filtration rate; GCS, Glasgow coma scale; RDW, red blood cell distribution width; SD, standard deviation
  2. *Continuous variables were compared using a t-test and categorical variables, including missingness, were compared using a Chi-square test
  3. **P < 0.05 using a chi-square test, development versus test cohort
  4. Significance was set at 0.05
  5. +A single very high, but clinically consistent creatine kinase accounted for the very large mean in this group