Table 1. Study population characteristics according to the COVID-19 outbreak.
| Characteristics | Total | Before-COVID | After-COVID | P value | ||
|---|---|---|---|---|---|---|
| Total, ED visits | 11,662,167 | 6,765,717 | 4,896,450 | |||
| Incidence rate, per 100,000 person-days | 90.5 | 105.4 | 75.7 | |||
| Age, yr | < 0.001 | |||||
| 0–19 | 2,173,765 (18.6) | 1,498,748 (22.2) | 675,017 (13.8) | |||
| 20–39 | 2,642,574 (22.7) | 1,469,761 (21.7) | 1,172,813 (24.0) | |||
| 40–59 | 3,069,799 (26.3) | 1,723,911 (25.5) | 1,345,888 (27.5) | |||
| 60–79 | 2,726,324 (23.4) | 1,507,835 (22.3) | 1,218,489 (24.9) | |||
| 80–120 | 1,049,705 (9.0) | 565,462 (8.4) | 484,243 (9.9) | |||
| Sex, female | 5,756,688 (49.4) | 3,367,763 (49.8) | 2,388,925 (48.8) | < 0.001 | ||
| Insurance, medical aid | 1,328,499 (11.4) | 747,014 (11.0) | 581,485 (11.9) | < 0.001 | ||
| EMS use | 2,520,555 (21.6) | 1,363,410 (20.2) | 1,157,145 (23.6) | < 0.001 | ||
| Level of ED, 1 & 2 | 8,927,986 (76.6) | 5,190,587 (76.7) | 3,737,399 (76.3) | < 0.001 | ||
| Initial triage, severe | 690,729 (5.9) | 368,022 (5.4) | 322,707 (6.6) | < 0.001 | ||
| Symptom | ||||||
| Fever, ≥ 37.5°C | 4,166,049 (35.7) | 2,493,187 (36.9) | 1,672,862 (34.2) | < 0.001 | ||
| Mental change | 2,968,045 (25.5) | 1,714,594 (25.3) | 1,253,451 (25.6) | < 0.001 | ||
| Diagnosis | ||||||
| Respiratory disease | 1,038,083 (8.9) | 729,302 (10.8) | 308,781 (6.3) | < 0.001 | ||
| Cardiovascular disease | 246,761 (2.1) | 135,441 (2.0) | 111,320 (2.3) | < 0.001 | ||
| Neurologic disease | 224,108 (1.9) | 119,683 (1.8) | 104,425 (2.1) | < 0.001 | ||
| In-hospital mortality | 187,563 (1.6) | 94,521 (1.4) | 93,042 (1.9) | < 0.001 | ||
| ED | 63,265 (0.5) | 30,942 (0.5) | 32,323 (0.7) | < 0.001 | ||
| Hospital ward | 124,298 (1.1) | 63,579 (0.9) | 60,719 (1.2) | < 0.001 | ||
| Community factors | ||||||
| Per capita income tax | < 0.001 | |||||
| Q1 (Highest) | 2,914,922 (25.0) | 1,710,141 (25.3) | 1,204,781 (24.6) | |||
| Q2 | 2,940,435 (25.2) | 1,689,377 (25.0) | 1,251,058 (25.6) | |||
| Q3 | 2,917,213 (25.0) | 1,696,030 (25.1) | 1,221,183 (24.9) | |||
| Q4 | 2,889,597 (24.8) | 1,670,169 (24.7) | 1,219,428 (24.9) | |||
| Employment rate | < 0.001 | |||||
| Q1 (Highest) | 2,929,750 (25.1) | 1,704,561 (25.2) | 1,225,189 (25.0) | |||
| Q2 | 2,914,790 (25.0) | 1,694,021 (25.0) | 1,220,769 (24.9) | |||
| Q3 | 2,927,859 (25.1) | 1,696,883 (25.1) | 1,230,976 (25.1) | |||
| Q4 | 2,889,768 (24.8) | 1,670,252 (24.7) | 1,219,516 (24.9) | |||
| Proportion of service workers | < 0.001 | |||||
| Q1 (Lowest) | 2,897,607 (24.8) | 1,673,719 (24.7) | 1,233,888 (25.0) | |||
| Q2 | 3,165,814 (27.1) | 1,861,976 (27.5) | 1,303,838 (26.6) | |||
| Q3 | 2,678,180 (23.0) | 1,538,207 (22.7) | 1,139,973 (23.3) | |||
| Q4 | 2,920,566 (25.0) | 1,691,815 (25.0) | 1,228,751 (25.1) | |||
Values are presented as number of patients (%).
COVID-19 = coronavirus disease 2019, ED = emergency department, EMS = emergency medical services, Q = quartile.