Table 1. Baseline Characteristics of the Participants.
| Continuous positive airway pressure (n = 380) |
High-flow nasal oxygen (n = 418) |
Conventional oxygen therapy (n = 475) |
|
|---|---|---|---|
| Treatment period, No. (%) | |||
| Before July 2020 | 47 (12.4) | 44 (10.5) | 47 (9.9) |
| July 2020-January 2021 | 262 (69.0) | 289 (69.1) | 331 (69.7) |
| After January 2021 | 71 (18.7) | 85 (20.3) | 97 (20.4) |
| Age, mean (SD), y | 56.7 (12.5) | 57.6 (13.0) | 57.6 (12.7) |
| Sex, No. (%) | |||
| Male | 260 (68.4) | 272 (65.1) | 312 (65.7) |
| Female | 120 (31.6) | 146 (34.9) | 163 (34.3) |
| Race and ethnicity, No. (%)a | |||
| Asianb | 73 (19.2) | 77 (18.4) | 90 (18.9) |
| Blackc | 16 (4.2) | 14 (3.3) | 19 (4.0) |
| Multipled | 3 (0.8) | 4 (1.0) | 6 (1.3) |
| Whitee | 243 (63.9) | 276 (66.0) | 312 (65.7) |
| Otherf | 11 (2.9) | 12 (2.9) | 9 (1.9) |
| Not given | 33 (8.7) | 34 (8.1) | 35 (7.4) |
| Time from symptom onset, median (IQR), d | |||
| To hospital admission | (n = 376); 7.0 (5.5-10.0) | (n = 407); 8.0 (5.0-10.0) | (n = 466); 7.0 (5.0-10.0) |
| To randomization | (n = 378); 9.0 (7.0-12.0) | (n = 414); 9.0 (7.0-12.0) | (n = 470); 9.0 (6.0-12.0) |
| COVID-19 status, No. (%) | (n = 379) | (n = 417) | (n = 473) |
| Confirmed | 326 (85.8) | 355 (84.9) | 409 (86.1) |
| Suspected | 53 (13.9) | 62 (14.8) | 64 (13.5) |
| Comorbidities, No. (%) | |||
| Other (none of the below) | 148 (38.9) | 141 (33.7) | 188 (39.6) |
| Hypertension | 131 (34.5) | 164 (39.2) | 153 (32.2) |
| Diabetes requiring medication | 86 (22.6) | 98 (23.4) | 91 (19.2) |
| Morbid obesity (body mass index >35)g | 62 (16.3) | 81 (19.4) | 75 (15.8) |
| Chronic lung disease | 65 (17.1) | 52 (12.4) | 66 (13.9) |
| Coronary heart disease | 34 (8.9) | 26 (6.2) | 44 (9.3) |
| Uncontrolled or active malignancy | 7 (1.8) | 10 (2.4) | 7 (1.5) |
| Dementia | 4 (1.1) | 1 (0.2) | 3 (0.6) |
| End-stage kidney disease requiring kidney replacement therapy | 2 (0.5) | 6 (1.4) | 5 (1.1) |
| Congestive heart failure | 2 (0.5) | 4 (1.0) | 5 (1.1) |
| Clinical Frailty Scale, No. (%)h | |||
| Very fit to managing welli | 351 (92.4) | 376 (90.0) | 430 (90.5) |
| Very mild frailty to terminally illj | 19 (5.0) | 35 (8.4) | 39 (8.2) |
| Respiratory rate, median (IQR), /min | (n = 377); 24 (21-30) | (n = 414); 24 (20-29) | (n = 472); 23 (20-28) |
| Fio2, median (IQR) | (n = 363); 0.60 (0.40-0.80) | (n = 404); 0.60 (0.40-0.80) | (n = 459); 0.60 (0.40-0.80) |
| Spo2, median (IQR), % | (n = 378); 94.0 (92.0-95.0) | (n = 409); 93.0 (91.0-95.0) | (n = 470); 94.0 (92.0-95.0) |
| Ratio of Spo2 to Fio2, median (IQR), % | (n = 363); 155.0 (110.6-232.5) | (n = 399); 156.7 (113.8-232.5) | (n = 457); 156.7 (115.0-230.0) |
| Pao2, median (IQR), mm Hg | (n = 238); 67.5 (60.0-77.3) | (n = 287); 66.0 (59.3-74.3) | (n = 317); 66.8 (58.5-80.3) |
| Ratio of Pao2 to Fio2, median (IQR), mm Hg | (n = 229); 112.5 (80.0-161.3) | (n = 284); 115.0 (80.9-168.4) | (n = 308); 113.8 (84.8-150.9) |
| Paco2, median (IQR), mm Hg | (n = 252); 33.0 (30.0-36.8) | (n = 306); 33.0 (30.0-36.0) | (n = 331); 33.8 (30.8-36.8) |
Abbreviations: Fio2, fraction of inspired oxygen; Spo2, oxygen saturation as measured by pulse oximetry.
Categories were based on the NHS Data Model and Dictionary.
Asian-Indian, Asian-Pakistani, Asian-Bangladeshi, multiple-White and Asian, or any other Asian background.
Black/African/Caribbean/Black British-African, Black/African/Caribbean/Black British-Caribbean, Black/African/Caribbean/Black British, or any other Black/African/Caribbean/Black British background.
Any other multiple racial and ethnic combination.
White British, White Irish, multiple-White and Black Caribbean, multiple-White and Black African, or any other White background.
Chinese or any other racial and ethnic combination not listed in footnotes b through e.
Body mass index is calculated as weight in kilograms divided by height in meters squared.
Based on functional status prior to hospital admission and determined through chart review or patient assessment. It is measured on a 9-point scale (very fit to terminally ill) with lower scores indicating better functional status and a lower level of frailty.
Categories correspond to scores of 1 to 3.
Categories correspond to scores of 4 to 9.