TABLE 1.
Baseline characteristics
| Before PS matching | After PS matching | |||||
|---|---|---|---|---|---|---|
| Triage group (n = 363) | After examination group (n = 2191) | Standardized difference (%) | Triage group (n = 329) | After examination group (n = 329) | Standardized difference (%) | |
| Age (y), mean (SD) | 40.5 ± 15.0 | 43.3 ± 17.5 | 0.175 | 40.8 ± 15.1 | 41.3 ± 16.7 | 0.033 |
| Sex (male) | 200 (55.1%) | 1,016 (46.4%) | 0.175 | 173 (52.6%) | 172 (52.3%) | 0.006 |
| Risk factors for influenza‐related complications | 98 (27.0%) | 819 (37.4%) | 0.224 | 96 (29.2%) | 95 (28.9%) | 0.007 |
| Any of the following symptoms: | 363 (100%) | 2,169 (99.0%) | 0.142 | 329 (100%) | 329 (100%) | NA |
| Fever | 350 (96.4%) | 2,009 (91.7%) | 0.201 | 316 ( (96.0%) | 319 (97.0%) | 0.050 |
| Chill | 129 (35.5%) | 846 (38.6%) | 0.064 | 119 (36.2%) | 119 (36.2%) | 0 |
| Fatigue | 77 (21.2%) | 397 (18.1%) | 0.078 | 68 (20.7%) | 67 (20.4%) | 0.008 |
| Cough | 236 (65.0%) | 1,528 (69.7%) | 0.101 | 214 (65.0%) | 225 (68.4%) | 0.071 |
| Nasal discharge | 163 (44.9%) | 1,119 (51.1%) | 0.124 | 152 (46.2%) | 157 (47.7%) | 0.030 |
| Throat pain | 220 (60.6%) | 1,354 (61.8%) | 0.024 | 202 (61.4%) | 208 (63.2%) | 0.038 |
| Joint pain | 160 (44.1%) | 1,094 (49.9%) | 0.118 | 143 (43.5%) | 135 (41.0%) | 0.049 |
| Headache | 133 (36.6%) | 1,000 (45.6%) | 0.184 | 127 (38.6%) | 127 (38.6%) | 0 |
| Sputum production | 84 (23.1%) | 697 (31.8%) | 0.195 | 80 (24.3%) | 85 (25.8%) | 0.035 |
| Muscle pain | 48 (13.2%) | 282 (12.9%) | 0.010 | 44 (13.4%) | 34 (10.3%) | 0.094 |
| Vital signs | ||||||
| Temperature (°C), mean (SD) | 38.2 ± 0.8 | 38.1 ± 0.9 | 0.115 | 38.2 ± 0.8 | 38.1 ± 0.9 | 0.076 |
| Pulse rate (bpm), mean (SD) | 101.3 ± 15.3 | 100.1 ± 16.5 | 0.073 | 101.2 ± 15.5 | 100.2 ± 15.5 | 0.068 |
| MAP (mm Hg), mean (SD) | 91.3 ± 14.2 | 92.3 ± 15.1 | 0.068 | 90.9 ± 14.4 | 91.4 ± 14.7 | 0.032 |
| JTAS score | 0.255 | 0.040 | ||||
| 1 | 0 | 0 | 0 | 0 | ||
| 2 | 5 (1.4%) | 72 (3.3%) | 5 (1.5%) | 4 (1.2%) | ||
| 3 | 94 ( (25.9%) | 773 (35.3%) | 88 (26.7%) | 84 (25.5%) | ||
| 4 | 261 (71.9%) | 1,327 (60.6%) | 234 (71.1%) | 239 (72.6%) | ||
| 5 | 3 (0.8%) | 19 (0.9%) | 2 (0.6%) | 2 (0.6%) | ||
| Positive RIDT (A or B) | 187 (51.5%) | 756 (34.5%) | 0.349 | 162 (49.2%) | 160 (48.6%) | 0.012 |
| Arrival‐to‐triage time (min), median (IQR) | 19 (12–32) | 14 (9–22) | 0.394 | 18 (12–28) | 17 (10–29) | 0.003 |
MAP, systolic pressure + 2 × diastolic pressure)/3. Arrival‐to‐triage time, from the time the patient was registered to the ED index to the triage time recorded on the triage template. Risk factors for influenza‐related complications are described in detail in the Supporting Information Appendix S2.
ED, emergency department; IQR, interquartile range; JTAS, Japan Triage and Acuity Scale; MAP, mean arterial pressure; PS, propensity score; RIDT, rapid influenza diagnostic test.