Table 1.
Study population demographics stratified by oxygen treatment and CPAP treatment. 1n (%); Median (IQR). 2Fisher's exact test; Wilcoxon rank sum test. Abbreviations used: HIV, human immunodeficiency virus; CFS, clinical frailty scale; CRP, C-reactive protein; FiO2, fraction of inspired oxygen; RR, respiratory rate; SpO2, pulse oximetry.
| Variable | Overall, N = 4791 | Treatment group |
p-value [2] | |
|---|---|---|---|---|
| Oxygen N = 2461 | CPAP N = 2331 | |||
| Ethnicity | 0.3 | |||
| Black | 8 (1.7%) | 6 (2.4%) | 2 (0.9%) | |
| Chinese | 1 (0.2%) | 1 (0.4%) | 0 (0%) | |
| South Asian | 26 (5.4%) | 15 (6.1%) | 11 (4.7%) | |
| White | 443 (93%) | 223 (91%) | 220 (94%) | |
| Age | 77 (71, 83) | 78 (72, 85) | 77 (70, 82) | 0.004 |
| Sex (male) | 307 (64%) | 151 (61%) | 156 (67%) | 0.2 |
| Comorbidities | ||||
| Cardiac | 334 (70%) | 186 (76%) | 148 (64%) | 0.004 |
| Respiratory | 171 (36%) | 87 (35%) | 84 (36%) | 0.9 |
| Chronic kidney disease | 74 (15%) | 34 (14%) | 40 (17%) | 0.3 |
| Liver | 28 (5.8%) | 12 (4.9%) | 16 (6.9%) | 0.4 |
| Dementia | 19 (4.0%) | 11 (4.5%) | 8 (3.4%) | 0.6 |
| Neurological | 74 (15%) | 35 (14%) | 39 (17%) | 0.4 |
| Obesity | 138 (29%) | 79 (32%) | 59 (25%) | 0.10 |
| HIV | 3 (0.6%) | 0 (0%) | 3 (1.3%) | 0.11 |
| Diabetes | 158 (33%) | 92 (37%) | 66 (28%) | 0.035 |
| Cancer | 92 (19%) | 40 (16%) | 52 (22%) | 0.093 |
| Comorbidity score (grouped) | 0.3 | |||
| A (0,1) | 150 (31%) | 70 (28%) | 80 (34%) | |
| B (2) | 167 (35%) | 93 (38%) | 74 (32%) | |
| C (3-5) | 162 (34%) | 83 (34%) | 79 (34%) | |
| CFS | 0.4 | |||
| 2-3 | 116 (24%) | 59 (24%) | 57 (24%) | |
| 4 | 113 (24%) | 60 (24%) | 53 (23%) | |
| 5 | 152 (32%) | 84 (34%) | 68 (29%) | |
| 6 | 98 (20%) | 43 (17%) | 55 (24%) | |
| Urea (mmol/L) | 9 (6, 13) | 10 (6, 14) | 8 (6, 13) | 0.13 |
| CRP (mg/L) | 131 (78, 196) | 118 (66, 189) | 146 (89, 206) | 0.008 |
| Inclusion FiO2 (grouped) | <0.001 | |||
| 0.4-0.59 | 154 (32%) | 103 (42%) | 51 (22%) | |
| 0.6-0.79 | 123 (26%) | 58 (24%) | 65 (28%) | |
| 0.8 | 202 (42%) | 85 (35%) | 117 (50%) | |
| Inclusion RR (breaths/minute) | 24 (20, 28) | 22 (20, 26) | 26 (22, 30) | <0.001 |
| Inclusion SpO2 (%) | 92 (88-94) | 92 (90, 94) | 92 (88, 95) | 0.2 |
| Duration: admission to inclusion (days) | 2 (0, 5) | 1 (0, 5) | 2 (0, 4) | 0.5 |