Table 3.
Comparison of the major characteristics, drug administration, and oxygen support during hospitalisation among each wave.
| Variable | Wave 1 | Wave 2 | Wave 3 | Wave 1 vs Wave 2 | Wave 1 vs Wave 3 | Wave 2 vs Wave 3 | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Number (%) | Estimated difference* [confidence interval†] | P value‡ | Estimated difference* [confidence interval†] | P value‡ | Estimated difference* [confidence interval†] | P value‡ | |||||
| Patient demographics and characteristics on admission | |||||||||||
| Age, median [IQR], years | 56 [40, 71] |
50 [30, 69] |
64 [47, 78] |
6.0 [5.0, 7.0] |
<0.001 | -6.0 [-7.0, -5.0] |
<0.001 | -12.0 [-12.0, -11.0] |
<0.001 | ||
| Male sex | 3139 (58.5) | 6784 (58) |
9062 (55) | 0.004 [-0.015, 0.024] |
0.598 | 0.035 [0.016, 0.054] |
<0.001 | 0.031 [0.016, 0.045] |
<0.001 | ||
| Severe disease at admission | 1767 (32.9) | 2544 (21.8) | 5276 (32) | 0.111 [0.093, 0.129] |
<0.001 | 0.009 [-0.009, 0.027] |
0.228 | -0.102 [-0.115, -0.090] |
<0.001 | ||
| ComorbiditiesA | |||||||||||
| Cardiovascular disease | 268 (5) |
408 (3.5) |
973 (5.9) | 0.015 [0.007, 0.023] |
<0.001 | -0.009 [-0.018, -0.001] |
0.001 | -0.024 [-0.030, -0.018] |
<0.001 | ||
| Chronic respiratory disease | 109 (2) |
133 (1.1) |
263 (1.6) | 0.010 [0.002, 0.018] |
0.001 | -0.003 [-0.010, 0.005] |
0.381 | -0.013 [-0.018, -0.007] |
<0.001 | ||
| Liver disease | 130 (2.4) | 235 (2) |
422 (2.6) | 0.004 [-0.002, 0.010] |
0.096 | -0.001 [-0.007, 0.005] |
0.607 | -0.005 [-0.010, -0.001] |
0.003 | ||
| Diabetes Mellitus | 856 (15.9) | 1509 (12.9) | 3191 (19.4) | 0.030 [0.016, 0.044] |
<0.001 | -0.034 [-0.048, -0.020] |
<0.001 | -0.064 [-0.075, -0.054] |
<0.001 | ||
| Cerebrovascular disease | 337 (6.3) | 552 (4.7) |
1342 (8.1) | 0.016 [0.006, 0.025] |
<0.001 | -0.019 [-0.028, -0.009] |
<0.001 | -0.034 [-0.041, -0.027] |
<0.001 | ||
| Hypertension | 1050 (19.5) | 2831 (24.2) | 6068 (36.8) | -0.047 [-0.063, -0.030] |
<0.001 | -0.173 [-0.188, -0.157] |
<0.001 | -0.126 [-0.139, -0.113] |
<0.001 | ||
| BMI>=25 | 1366 (32.8) | 3171 (33.2) | 4762 (35.4) | -0.004 [-0.025, 0.017] |
0.688 | -0.025 [-0.045, -0.005] |
<0.003 | -0.021 [-0.037, -0.006] |
0.001 | ||
| Drug administration | |||||||||||
| Steroid (excl. ciclesonide) | 497 (9.4) | 2384 (20.4) | 6569 (39.9) | -0.110 [-0.124, -0.097] |
<0.001 | -0.305 [-0.318, -0.292] |
<0.001 | -0.195 [-0.207, -0.182] |
<0.001 | ||
| Tocilizumab | 66 (2.6) |
259 (5.6) |
393 (4.7) | -0.030 [-0.041, -0.019] |
<0.001 | -0.022 [-0.032, -0.012] |
<0.001 | 0.008 [-0.002, 0.018] |
0.051 | ||
| Remdesivir | 2 (0.9) |
1074 (23.2) | 2682 (32.4) | -0.223 [-0.239, -0.208] |
<0.001 | -0.315 [-0.329, -0.302] |
<0.001 | -0.092 [-0.112, -0.073] |
<0.001 | ||
| Favipiravir | 2037 (69.5) | 2664 (57.4) | 4415 (53.3) | 0.122 [0.095, 0.149] |
<0.001 | 0.164 [0.139, 0.188] |
<0.001 | 0.042 [0.020, 0.064 |
<0.001 | ||
| Anticoagulant | 538 (10.0) | 1416 (12.1) | 3674 (22.3) | -0.021 [-0.034, -0.009] |
<0.001 | -0.123 [-0.136, -0.111] |
<0.001 | -0.102 [-0.113, -0.091] |
<0.001 | ||
| Oxygen support | |||||||||||
| Any formB | 2063 (38.4) | 3069 (26.3) | 6554 (39.7) | 0.070 [0.055, 0.084] |
<0.001 | -0.007 [-0.021, 0.007] |
0.254 | -0.076 [-0.087, -0.066] |
<0.001 | ||
| High-flow nasal canula | 110 (2.0) |
181 (1.5) |
415 (2.5) | 0.005 [-0.001, 0.010] |
0.025 | -0.004 [-0.010, 0.001] |
0.064 | -0.009 [-0.013, -0.005] |
<0.001 | ||
| BiPAP/CPAP | 32 (0.6) |
103 (0.9) |
101 (0.6) | -0.003 [-0.006, 0.001] |
0.065 | -0.0002 [-0.003, 0.003] |
0.972 | 0.003 [-0.0001, 0.005] |
0.011 | ||
| IMV | 441 (8.2) | 371 (3.2) |
629 (3.8) | 0.045 [0.036, 0.054] |
<0.001 | 0.039 [0.030, 0.048] |
<0.001 | -0.006 [-0.011, -0.001] |
0.006 | ||
| ECMO | 83 (1.5) |
29 (0.2) |
35 (0.2) |
0.013 [0.008, 0.017] |
<0.001 | 0.013 [0.009, 0.017] |
<0.001 | 0.0004 [-0.001, 0.002] |
0.622 | ||
Earlier wave was used as reference.
†98.33% confidence intervals were calculated because significance threshold was corrected by Bonferroni method.
Bonferroni correction was used for pairwise comparisons among waves (threshold of significant difference was 0.0167). Statistically significant values are shown in bold.
Abbreviations. BiPAP/CPAP, bilevel positive airway pressure/continuous positive airway pressure; BMI, body mass index; ECMO, extracorporeal membrane oxygenation; IMV, invasive mechanical ventilation; IQR, interquartile range.
A Cardiovascular disease includes myocardial infarction/Congestive heart failure. Chronic respiratory disease was defined as pulmonary disease in patients who were dyspneic with slight activity and included chronic obstructive pulmonary disease.
B Any form of oxygen support includes high-flow nasal canula, non-IMV, IMV, ECMO, and other oxygen support (e.g. nasal cannula, mask).