Table 1.
Characteristics and Outcomes of Patients Directly Admitted to the Ward
| … | All Patients | 1st Wave | 2nd Wave | 3rd Wave | 4th Wave | P |
|---|---|---|---|---|---|---|
| Number of patients admitted with COVID-19 | 5187 | 2458 | 1542 | 701 | 486 | |
| Dominant strain | … | Original (Wuhan) strain | Original (Wuhan) strain | Alpha | Delta | |
| Demographics | … | … | … | … | … | |
| Sex—male, No. (%) | 3048 (58.8) | 1499 (61.0) | 898 (58.2) | 404 (57.7) | 247 (50.9)a,b | <.001 |
| Age, median [IQR], y | 66.10 [56.00–77.00] | 68.00 [57.00–78.00] | 67.00 [57.00–77.00] | 63.00 [52.00–72.00]a,b | 65.00 [51.00–77.00]a,b | <.001 |
| Body mass index, median [IQR], kg/m2 | 27.47 [24.52–31.41] | 27.16 [24.39–30.83] | 27.51 [24.58–31.53] | 28.06 [24.85–32.44]a | 28.08 [24.66–32.72]a | .001 |
| Race, No. (%) | … | … | a | a | a,c | <.001 |
| Arab | 417 (9.7) | 171 (8.1) | 144 (11.3) | 56 (10.9) | 46 (11.4) | |
| Asian | 227 (5.3) | 98 (4.6) | 81 (6.4) | 37 (7.2) | 11 (2.7) | |
| Black | 428 (10.0) | 144 (6.8) | 155 (12.2) | 70 (13.7) | 59 (14.7) | |
| White | 3087 (71.8) | 1651 (78.2) | 840 (66.0) | 321 (62.7) | 275 (68.4) | |
| Other | 139 (3.2) | 47 (2.2) | 53 (4.2) | 28 (5.5) | 11 (2.7) | |
| Baseline characteristics | … | … | … | … | … | |
| Days since onset of symptoms, median [IQR] | 8.00 [5.00–11.00] | 7.00 [5.00–12.00] | 8.00 [5.00–11.00] | 9.00 [6.00–11.00]a,b | 7.00 [4.00–9.00]a,b,c | <.001 |
| Transfer from other hospital, No. (%) | 281 (5.4) | 49 (2.0) | 93 (6.0)a | 109 (15.5)a,b | 30 (6.2)a,c | <.001 |
| Do not resuscitate and/or intubate order, No. (%) | 1426 (31.0) | 722 (35.8) | 423 (28.9)a | 147 (21.7)a,b | 134 (30.0)c | <.001 |
| Vaccinated against SARS-CoV-2, No. (%) | 261 (9.2) | 0 (0.0) | 1 (0.1) | 56 (8.8)a,b | 204 (45.0)a,b,c | <.001 |
| Medical history | … | … | … | … | … | |
| Patients with comorbidities,d No. (%) | 3843 (83.7) | 1778 (83.2) | 1188 (85.4) | 493 (81.8) | 384 (83.7) | .170 |
| Number of comorbidities,d median [IQR] | 2.00 [1.00–3.00] | 2.00 [1.00–3.00] | 2.00 [1.00–3.00] | 2.00 [1.00–3.00]a,b | 2.00 [1.00–3.00] | .002 |
| Asthma or other chronic pulmonary disease, No. (%) | 1307 (25.4) | 632 (26.0) | 419 (27.3) | 160 (22.9) | 96 (19.8)a,b | .003 |
| Chronic cardiac disease, No. (%) | 1537 (29.9) | 750 (30.8) | 455 (29.8) | 180 (25.9) | 152 (31.3) | .081 |
| Chronic kidney disease, No. (%) | 672 (13.1) | 299 (12.3) | 214 (14.0) | 90 (12.9) | 69 (14.2) | .406 |
| Diabetes, No. (%) | 1058 (20.4) | 464 (18.9) | 360 (23.3)a | 138 (19.7) | 96 (19.8) | .007 |
| Hypertension, No. (%) | 2300 (44.7) | 1127 (46.1) | 701 (46.0) | 274 (39.3)a,b | 198 (41.0) | .003 |
| Malignancy, No. (%) | 385 (7.5) | 196 (8.1) | 118 (7.7) | 39 (5.6) | 32 (6.6) | .140 |
| Organ transplantation, No. (%) | 128 (2.5) | 32 (1.3) | 30 (2.0) | 36 (5.2)a,b | 30 (6.4)a,b | <.001 |
| Disease severity | … | … | … | … | … | |
| MEWS, median [IQR] | 2.00 [1.00–4.00] | 3.00 [1.00–4.00] | 2.00 [1.00–4.00] | 2.00 [1.00–3.00]a | 3.00 [2.00–4.00]c | <.001 |
| CT Severity Score, median [IQR] | 10.00 [6.00–14.00] | 8.00 [5.00–12.00] | 11.00 [8.00–15.00]a | 12.00 [10.00–16.00]a,b | 12.00 [9.00–15.00]a | <.001 |
| 4C Mortality Score, median [IQR] | 10.00 [7.00–13.00] | 10.00 [6.00–13.00] | 10.00 [7.00–13.00] | 9.00 [6.00–12.00]b | 10.00 [7.00–13.00]c | .002 |
| Outcomes | … | … | … | … | … | |
| Venous thromboembolism, No. (%) | 278 (5.4) | 133 (5.4) | 75 (4.9) | 43 (6.1) | 27 (5.6) | .654 |
| Length of hospital stay, median [IQR], d | 6.00 [3.00–11.00] | 5.00 [3.00–10.00] | 6.00 [3.00–10.00]a | 7.00 [4.00–12.00]a,b | 8.00 [4.00–14.00]a,b | <.001 |
| In-hospital mortality, No. (%) | 891 (17.2) | 510 (20.7) | 223 (14.5)a | 84 (12.0)a | 74 (15.2)a | <.001 |
| 12-wk mortality, No. (%) | 973 (18.8) | 550 (22.4) | 249 (16.1)a | 96 (13.7)a | 78 (16.0)a | <.001 |
| ICU admission, No. (%) | 686 (13.2) | 309 (12.6) | 172 (11.2) | 119 (17.0)a,b | 86 (17.7)a,b | <.001 |
| Mechanical ventilation, No. (%) | 497 (72.9) | 263 (85.7) | 112 (65.5)a | 74 (62.7)a | 48 (55.8)a | <.001 |
| Ventilator-free days, median [IQR] | 13.00 [0.00–22.00] | 8.00 [0.00–19.00] | 13.00 [0.00–23.00] | 20.00 [0.00–25.00]a | 19.50 [0.00–23.00]a | <.001 |
| Length of ICU stay, median [IQR], d | 8.00 [3.00–16.00] | 10.00 [5.00–19.00] | 7.00 [2.00–15.00]a | 7.00 [3.00–13.00]a | 5.00 [2.00–11.00]a | <.001 |
| ICU mortality, No. (%) | 167 (24.3) | 88 (28.5) | 42 (24.4) | 23 (19.3) | 14 (16.3) | .057 |
Abbreviations: CT, computed tomography; ICU, intensive care unit; MEWS, Modified Early Warning Score.
Significant vs first wave using a Dunn's test of multiple comparisons using rank sums for nonparametric continuous variables, a Tukey test for parametric continuous variables, and a Bonferroni correction for categorical variables.
Significant vs second wave using a Dunn's test of multiple comparisons using rank sums for nonparametric continuous variables, a Tukey test for parametric continuous variables, and a Bonferroni correction for categorical variables.
Significant vs third wave using a Dunn's test of multiple comparisons using rank sums for nonparametric continuous variables, a Tukey test for parametric continuous variables, and a Bonferroni correction for categorical variables.
Comorbidities include chronic cardiac disease, hypertension, chronic pulmonary disease, asthma, chronic kidney disease, liver disease, chronic neurologic disease, malignancy, chronic hematologic disease, HIV or AIDS, diabetes, rheumatic disorder, auto-immune disease, dementia, and obesity.