Table 1.
Patient characteristics and interventions among unmatched and propensity score-matched patients with and without steroid therapy
| Unmatched patients | Propensity score-matched patients | ||||||
|---|---|---|---|---|---|---|---|
| All N = 692 |
With steroid pulse therapy N = 329 |
Without steroid pulse therapy N = 363 |
Absolute standardized difference (%) | With steroid pulse therapy N = 168 |
Without steroid pulse therapy N = 168 |
Absolute standardized difference (%) | |
| Age category | |||||||
| < 1 year, n (%) | 27 (3.9) | 15 (4.6) | 12 (3.3) | 6.5 | 3 (1.8) | 4 (2.4) | 4.2 |
| 1–5 years, n (%) | 376 (54.3) | 189 (57.4) | 187 (51.5) | 11.9 | 90 (53.6) | 85 (50.6) | 6.0 |
| 6–11 years, n (%) | 223 (32.2) | 100 (30.4) | 123 (33.9) | 7.5 | 57 (33.9) | 59 (35.1) | 2.5 |
| 12–18 years, n (%) | 66 (9.5) | 25 (7.6) | 41 (11.3) | 12.7 | 18 (10.7) | 20 (11.9) | 3.8 |
| Male, n (%) | 386 (55.8) | 174 (52.9) | 212 (58.4) | 11.1 | 100 (59.5) | 102 (60.7) | 2.4 |
| Congenital anomaly, n (%) | 8 (1.2) | 4 (1.2) | 4 (1.1) | 1.1 | 1 (0.6) | 2 (1.2) | 6.3 |
| Epilepsya, n (%) | 115 (16.6) | 67 (20.4) | 48 (13.2) | 19.2 | 22 (13.1) | 29 (17.3) | 11.6 |
| JCS category at admission | |||||||
| JCS 0, n (%) | 310 (44.8) | 110 (33.4) | 200 (55.1) | 44.7 | 73 (43.5) | 65 (38.7) | 9.7 |
| JCS 1–3, n (%) | 164 (23.7) | 87 (26.4) | 77 (21.2) | 12.3 | 40 (23.8) | 46 (27.4) | 8.2 |
| JCS 10–30, n (%) | 91 (13.2) | 45 (13.7) | 46 (12.7) | 30.0 | 26 (15.5) | 28 (16.7) | 3.2 |
| JCS 100–300, n (%) | 127 (18.4) | 87 (26.4) | 40 (11.0) | 40.3 | 29 (17.3) | 29 (17.3) | 0.0 |
| Anti-influenza agents within 2 days, n (%) | 493 (71.2) | 277 (84.2) | 216 (59.5) | 57.0 | 134 (79.8) | 132 (78.6) | 2.9 |
| Intravenous antiepileptic drugs within 2 days, n (%) | 384 (55.5) | 250 (76.0) | 134 (36.9) | 85.6 | 102 (60.7) | 109 (64.9) | 8.6 |
| Acetaminophen within 2 days, n (%) | 298 (43.1) | 152 (46.2) | 146 (40.2) | 12.1 | 78 (46.4) | 82 (48.8) | 4.8 |
| Mechanical ventilation within 2 days, n (%) | 75 (10.8) | 60 (18.2) | 15 (4.1) | 45.8 | 8 (4.8) | 12 (7.1) | 10.0 |
| Vasoactive agents within 2 days, n (%) | 24 (3.5) | 19 (5.8) | 5 (1.4) | 23.8 | 3 (1.8) | 5 (3.0) | 7.8 |
| CT or MRI within 2 days, n (%) | 549 (79.3) | 310 (94.2) | 239 (65.8) | 75.8 | 156 (92.9) | 160 (95.2) | 10.0 |
| Cerebrospinal fluid examination within 2 days, n (%) | 313 (45.2) | 198 (60.2) | 115 (31.7) | 59.6 | 83 (49.4) | 85 (50.6) | 2.4 |
| Admission to ICU within 2 days, n (%) | 76 (11.0) | 52 (15.8) | 24 (6.6) | 29.4 | 13 (7.7) | 17 (10.1) | 8.3 |
| Immunoglobulin within 2 days, n (%) | 103 (14.9) | 96 (29.2) | 7 (1.9) | 81.0 | 6 (3.6) | 7 (4.2) | 3.1 |
JCS Japan Coma Scale, CT Computerized tomography, MRI Magnetic resonance imaging, ICU Intensive care unit
aEpilepsy patients did not include those diagnosed after the incidence of influenza virus-associated encephalopathy