Table 1.
Clinical Characteristics of Patients Transferred in the First Four COVID-19 Pandemic Waves
| Characteristic | All Patients (N = 1,468) (Waves 1-4) | First Wavec (n = 450) | Second/Third/Fourth Waved (n = 1,018) | P |
|---|---|---|---|---|
| Age, mean (SD), y | 60.6 (12.5) | 60.1 (12.3) | 61.0 (12.8) | .702 |
| Male sex | 1,029 (70.1) | 311 (69.1) | 718 (70.5) | .326 |
| Hypertension | 756 (51.5) | 218 (51.2) | 538 (52.8) | .069 |
| Diabetes mellitus | 392 (26.7) | 113 (25.2) | 279 (27.4) | .660 |
| Obesity (BMI ≥ 30) | 383 (26.1) | 116 (26.0) | 267 (26.2) | .821 |
| Active smoking | 106 (7.2) | 22 (4.9) | 84 (8.3) | .031 |
| Respiratory backgrounda | 352 (24.0) | 91 (20.1) | 261 (25.6) | .019 |
| Comorbidities b | 247 (16.8) | 82 (18.0) | 165 (16.2) | .103 |
| Clinical frailty scale (CFS) | .034 |
|||
| 1 | 184 (12.5) | 75 (16.7) | 109 (10.7) | |
| 2 | 716 (48.8) | 209 (46.4) | 507 (49.8) | |
| 3 | 514 (35.0) | 147 (32.7) | 367 (36.1) | |
| ≥4 | 54 (3.7) | 19 (4.2) | 35 (3.5) | |
| Nonintubated before transfer | 448 (30.5) | 66 (14.7) | 382 (37.5) | < .001 |
| Only oxygen mask | 51 (3.5) | 21 (4.7) | 30 (2.9) | |
| HNF | 177 (12.0) | 23 (5.1) | 154 (15.1) | |
| NIV | 57 (3.9) | 15 (3.3) | 42 (4.1) | |
| Both HNF and NIV | 163 (11.1) | 7 (1.6) | 156 (15.3) | |
| Intubated before transfer | 1020 (69.5) | 384 (85.3) | 636 (62.5) | < .001 |
| Oxygen mask prior intubation | 376 (25.6) | 233 (51.8) | 143 (14.0) | |
| HNF prior intubation | 267 (18.2) | 74 (16.4) | 193 (18.9) | |
| NIV prior intubation | 228 (15.5) | 67 (14.9) | 161 (15.8) | |
| Both HNF and NIV prior intubation | 149 (10.2) | 10 (2.2) | 139 (13.7) | |
| PAo2/Fio2 ratio, mean (SD) | 117.4 (52.6) | 113.2 (55.1) | 119.3 (50.3) | .010 |
| Need for pronation prior transfer | 248 (16.9) | 112 (24.9) | 136 (13.3) | < .001 |
| Acidosis or shock | 185 (19.4) | 67 (14.9) | 118 (11.6) | < .001 |
| Acute renal failure | 388 (26.4) | 108 (24.0) | 280 (27.5) | .044 |
| ICU at issuing hospital | 417 (28.4) | 129 (28.7) | 288 (28.3) | .580 |
| Location before transfer: | ||||
| ICU | 128 (8.7) | 57 (12.7) | 71 (7.0) | .025 |
| ED | 1,095 (74.6) | 314 (69.8) | 781 (76.7) | .038 |
| Semi-critical care unit | 245 (16.7) | 79 (17.5) | 166 (16.3) | .464 |
| Days of ICU stay after transfer, mean (SD) | 18.6 (14.4) | 19.3 (16.7) | 18.2 (13.4) | .297 |
| High risk of death according to TIHCOVID scale | 305 (20.8) | 102 (22.7) | 203 (19.9) | < .001 |
| Hospital mortality | 429 (29.2) | 152 (33.8) | 277 (27.2) | < .001 |
Values are No. (%) for categorical variables and mean (SD) for continuous variables. The Student t or the χ2 were used to compare the subgroups. Test were two-tailed, and P values below .05 were considered statistically significant. HNF = high nasal flow; NIV = noninvasive mechanical ventilation; TIHCOVID = interhospital transfers for COVID-19 patient.
Asthma, COPD GOLD class A-B, OSA/hypopnea syndrome.
Includes COPD GOLD class C-D, pulmonary fibrosis, cerebral vascular accident with sequelae, heart failure with New York Heart Association functional class III-IV, neurodegenerative diseases, active cancer, and Child B-C cirrhosis.
March 14, 2020 through April 30, 2020.
October 17, 2020 through April 30, 2021.