Baseline characteristics of the COVID-19 cohort according to mode of onset (fulminant vs non-fulminant onset)
| Parameter | Total n=2016 | Fulminant onset n=653 | Non-fulminant onset n=1363 | P value for difference |
| Categorical variables | ||||
| Age<50 years | 532 (26.4%) | 132 (20.2%) | 400 (29.3%) | |
| Age 50–60 years | 483 (23.9%) | 147 (22.5%) | 336 (24.7%) | |
| Age 60–70 years | 550 (27.3%) | 186 (28.5%) | 364 (26.7%) | <0.001 |
| Age 70–80 years | 324 (16.1%) | 124 (19.0%) | 200 (14.7%) | |
| Age>80 years | 127 (6.3%) | 64 (9.8%) | 63 (4.6%) | |
| Male | 1376 (68.2%) | 460 (70.4%) | 916 (67.2%) | 0.14 |
| Chronic smoking | 23 (1.1%) | 5 (0.7%) | 18 (1.3%) | 0.37 |
| Diabetes mellitus | 1044 (51.8%) | 370 (56.6%) | 674 (49.4%) | 0.002 |
| Hypertension | 818 (40.6%) | 312 (47.8%) | 506 (37.1%) | <0.001 |
| CKD | 82 (4.1%) | 43 (6.6%) | 39 (2.8%) | <0.001 |
| Chronic dialysis | 27 (1.3%) | 12 (1.8%) | 15 (1.1%) | 0.18 |
| CAD | 268 (13.3%) | 109 (16.7%) | 159 (11.7%) | 0.002 |
| Bronchial asthma | 74 (3.7%) | 25 (3.8%) | 49 (3.6%) | 0.80 |
| COPD | 17 (0.8%) | 9 (1.4%) | 8 (0.6%) | 0.07 |
| Immuno-suppressed | 15 (0.7%) | 10 (1.5%) | 5 (0.4%) | 0.004 |
| Vaccination status | ||||
| Unvaccinated | 1400 (69.4%) | 480 (73.5%) | 920 (67.5%) | |
| Partial | 135 (6.7%%) | 34 (5.2%) | 101 (7.4%) | 0.01 |
| Complete (two doses) | 205 (10.2%) | 54 (8.2%) | 151 (11.1%) | |
| Vaccination status missing | 276 (13.7%) | 85 (13.0%) | 191 (14.0%) | 0.54 |
| Vaccine type | ||||
| Covaxin (partial or complete) | 81 (4.0%) | 16 (2.4%) | 65 (4.8%) | |
| Covishield (partial or complete) | 207 (10.3%) | 57 (8.7%) | 150 (11.0%) | 0.007 |
| Vaccine type missing | 331 (16.4%) | 104 (15.9%) | 227 (16.7%) | 0.65 |
| Manifestations at hospitalisation | ||||
| Hypoxia (SaO2≤94) at admission | 909 (45.1%) | 538 (82.4%) | 371 (27.2%) | <0.001 |
| ARDS at admission | 96 (4.8%) | 67 (10.3%) | 29 (2.1%) | <0.001 |
| Invasive mechanical ventilation at admission | 35 (1.74%) | 24 (3.7%) | 11 (0.8%) | <0.001 |
| Shock at admission | 22 (1.1%) | 12 (1.8%) | 10 (0.7%) | 0.03 |
| AKI at admission | 326 (16.1%) | 210 (32.1%) | 116 (8.5%) | <0.001 |
| AKI—stage 3 | 31 (1.5%) | 18 (2.7%) | 13 (1.0%) | 0.004 |
| Acute encephalopathy at admission | 21 (1.0%) | 14 (2.1%) | 8 (0.6%) | 0.002 |
| Continuous variables | ||||
| Age in years mean (SD) median (IQR) range | 59.2 (14.2) 60 (50–70) 18–95 | 62.2 (13.7) 63 (53–72) 20–93 | 57.8 (14.3) 59 (49–68) 18–95 | <0.001 |
| SaO2 at admission mean (SD) median (IQR) range | 92.2 (8.5) 95 (91–97) 30–100 | 87.8 (10.7) 92 (85–94) 30–100 | 94.3 (6.3) 96 (94–98) 40–100 | <0.001 |
| D-dimer ng/mL mean (SD) median (IQR) range | 880.5 (1854.3) 300 (100–700) 9.6–16100 | 1182.8 (2302.5) 400 (140–900) 50–16 100 | 736.3 (1577.6) 240 (100–623) 9.6–14 800 | <0.001 |
| CRP mg/L mean (SD) median (IQR) range | 72.0 (85.7) 41 (12–104) 0.1–943 | 95.6 (94.1) 64 (25–139) 0.4–630 | 61.0 (79.2) 32 (10–88.5) 0.1–943 | <0.001 |
AKI, acute kidney injury; ARDS, acute respiratory distress syndrome; CAD, coronary artery disease; CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease; CRP, C reactive protein; SaO2, resting oxygen saturation.