Characteristics | Before PSM | After PSM | ||||
---|---|---|---|---|---|---|
Post-COVID-19 (n = 431) | Pre-COVID-19 (n = 326) | P value | Post-COVID-19 (n = 291) | Pre-COVID-19 (n = 291) | P value | |
Age (y), median (IQR) | 5.4 (3.6, 6.5) | 4.6 (3.3, 5.9) | 0.001 | 5.1 (3.5, 6.3) | 4.7 (3.3, 6.1) | 0.236 |
Male, n (%) | 250 (58.0) | 215 (66.0) | 0.026 | 190 (65.3%) | 183 (62.9%) | 0.545 |
BMI (kg/m2), median (IQR) | 18.0 (16.5, 19.5) | 17.1 (15.5, 18.9) | < 0.001 | 17.6 (16.3, 19.1) | 17.3 (15.9, 19.1) | 0.470 |
Vaccination status, n (%) | Â | Â | Â | Â | Â | Â |
 H1N1 vaccination | 16 (3.7) | 9 (2.8) | 0.468 | 10 (3.4) | 6 (2.1) | 0.311 |
 COVID-19 vaccination | 400 (92.8) | N/A | N/A | N/A | N/A | N/A |
  One-dose vaccination | 89 (20.6) | N/A | N/A | N/A | N/A | N/A |
  Two-dose vaccination | 201 (46.6) | N/A | N/A | N/A | N/A | N/A |
  Three-dose vaccination | 110 (25.5) | N/A | N/A | N/A | N/A | N/A |
Symptoms, n (%) | Â | Â | Â | Â | Â | Â |
 Fever | 420 (97.4) | 319 (97.9) | 0.717 | 282 (96.9) | 285 (97.9) | 0.433 |
  Duration of fever (d), median (IQR) | 4.0 (3.0, 6.0) | 2.5 (2.0, 4.0) | < 0.001 | 4.0 (3.0, 6.0) | 3.0 (2.0, 4.0) | < 0.001 |
  Fever peak (°C), median (IQR) | 39.0 (38.7, 39.4) | 38.8 (38.6, 39.3) | < 0.001 | 39.0 (38.7, 39.4) | 38.8 (38.6, 39.3) | < 0.001 |
 Cough | 395 (91.6) | 273 (83.7) | 0.001 | 264 (90.7) | 240 (82.5) | 0.003 |
 Rhinorrhea | 157 (36.4) | 114 (35.0) | 0.679 | 106 (36.4) | 99 (34.0) | 0.544 |
 Wheezing | 131 (30.4) | 75 (23.0) | 0.024 | 80 (27.5) | 67 (23.0) | 0.215 |
 Sore throat | 83 (19.3) | 61 (18.7) | 0.850 | 55 (18.9) | 59 (20.3) | 0.676 |
 Headache | 49 (11.4) | 33 (10.1) | 0.585 | 28 (9.6) | 28 (9.6) | 1.000 |
 Myalgia | 105 (24.4) | 86 (26.4) | 0.527 | 75 (25.8) | 74 (25.4) | 0.924 |
 Seizures | 78 (18.1) | 23 (7.1) | < 0.001 | 53 (18.2) | 22 (7.6) | < 0.001 |
 Drowsiness | 150 (34.8) | 104 (31.9) | 0.403 | 96 (33.0) | 98 (33.7) | 0.860 |
 Diarrhea | 49 (11.4) | 34 (10.4) | 0.682 | 29 (10.0) | 32 (11.0) | 0.685 |
 Vomiting | 62 (14.4) | 50 (15.3) | 0.715 | 37 (12.7) | 47 (16.2) | 0.238 |
 Abdominal pain | 32 (7.4) | 21 (6.4) | 0.600 | 22 (7.6) | 18 (6.2) | 0.512 |
Laboratory findings, median (IQR) | Â | Â | Â | Â | Â | Â |
 Leukocyte count (×109/L) | 6.3 (4.3, 9.0) | 6.0 (4.3, 8.5) | 0.341 | 6.1 (4.2, 8.7) | 6.0 (4.3, 8.7) | 0.707 |
 Neutrophil proportion (%) | 47.0 (31.0, 60.7) | 47.4 (31.8, 61.0) | 0.953 | 46.5 (30.7, 60.2) | 47.4 (32.4, 61.2) | 0.623 |
 Lymphocyte proportion (%) | 41.5 (28.0, 56.4) | 40.6 (28.2, 55.1) | 0.921 | 41.8 (29.6, 58.3) | 40.5 (27.6, 55.1) | 0.474 |
  Proportion of CD3+T cells (%) | 69.7 (64.2, 73.2) | 68.3 (64.8, 72.2) | 0.198 | 69.8 (65.6, 73.2) | 68.1 (64.1, 71.7) | 0.126 |
  Proportion of CD3+8+T cells (%) | 25.4 (21.3, 31.1) | 26.2 (21.5, 31.0) | 0.454 | 25.3 (21.2, 30.5) | 26.4 (22.3, 31.0) | 0.108 |
  Proportion of CD3+4+T cells (%) | 35.8 (28.3, 42.3) | 36.7 (30.9, 42.4) | 0.189 | 36.3 (30.0, 42.4) | 36.7 (31.1, 42.4) | 0.544 |
  Proportion of NK cells (%) | 12.7 (9.1, 16.6) | 12.1 (8.5, 15.6) | 0.071 | 12.7 (9.0, 16.4) | 12.2 (8.5, 15.6) | 0.208 |
  Proportion of B cells (%) | 18.9 (15.2, 22.5) | 18.4 (13.9, 22.8) | 0.417 | 18.7 (15.6, 22.5) | 18.5 (14.0, 23.0) | 0.665 |
 CRP (mg/L) | 15.4 (12.3, 23.1) | 11.7 (9.1, 14.6) | < 0.001 | 14.9 (12.5, 18.2) | 11.7 (8.8, 14.5) | < 0.001 |
 IL-6 (pg/mL) | 20.8 (16.9, 31.6) | 11.1 (5.6, 20.4) | < 0.001 | 20.5 (16.9, 30.1) | 11.0 (5.6, 21.0) | < 0.001 |
 IL-10 (pg/mL) | 16.6 (12.7, 22.3) | 15.0 (12.0, 20.5) | 0.020 | 16.5 (12.8, 22.2) | 14.9 (11.9, 20.6) | 0.030 |
 TNF-α (pg/mL) | 17.9 (14.0, 23.0) | 16.8 (12.8, 22.5) | 0.027 | 18.0 (13.8, 22.8) | 17.1 (13.3, 22.7) | 0.161 |
 CK-MB (U/L) | 44.9 (40.1, 53.1) | 36.0 (30.4, 42.8) | < 0.001 | 44.9 (40.7, 52.0) | 36.0 (30.2, 42.8) | < 0.001 |
 hs-TnT (pg/mL) | 4.6 (3.0, 6.9) | 4.3 (2.9, 7.0) | 0.401 | 4.7 (3.0, 6.9) | 4.3 (2.9, 7.2) | 0.433 |
 ALT (U/L) | 16.0 (12.0, 23.0) | 17.0 (12.0, 26.0) | 0.098 | 16.0 (12.0, 23.0) | 17.0 (12.0, 26.0) | 0.125 |
 AST (U/L) | 32.0 (24.0, 41.0) | 33.0 (24.0, 43.0) | 0.290 | 32.0 (23.0, 42.0) | 33.0 (24.0, 43.0) | 0.345 |
 Fibrinogen (g/L) | 3.9 (3.5, 4.6) | 3.7 (3.2, 4.6) | 0.005 | 3.9 (3.5, 4.7) | 3.7 (3.2, 4.7) | 0.046 |
Co-infection with SARS-CoV-2, n (%) | 55 (12.8) | N/A | N/A | N/A | N/A | N/A |
Mechanical ventilation, n (%) | 20 (4.6) | 4 (1.2) | 0.008 | 12 (4.1) | 4 (1.4) | 0.043 |
LOS (d), median (IQR) | 8.0 (7.0, 9.0) | 6.0 (5.0, 7.0) | < 0.001 | 8.0 (7.0, 9.0) | 6.0 (5.0, 7.0) | < 0.001 |
Severe H1N1 infection, n (%) | 93 (21.6) | 42 (12.9) | 0.002 | 60 (20.6) | 41 (14.1) | 0.038 |