Table 2. Patient characteristics by maximal respiratory support received.
| Air/oxygen1 215 (%) | CPAP2 45 (%) | IMV3 34 (%) | X2 test p-value4 | ||
|---|---|---|---|---|---|
| Socio-demographic characteristics | |||||
| Age (y) | Median (IQR) | 76 (63,85) | 67 (56,73) | 59 (51,67) | <0.001 |
| 20–49 | 19 (8.9) | 5 (11.1) | 8 (23.5) | <0.001 | |
| 50–59 | 26 (12.1) | 10 (22.2) | 10 (29.4) | ||
| 60–69 | 32 (14.9) | 11 (24.4) | 11 (32.4) | ||
| 70–79 | 54 (25.1) | 16 (35.6) | 5 (14.7) | ||
| 80–89 | 64 (29.8) | 2 (4.4) | 0 (0.0) | ||
| ≥ 90 | 20 (9.3) | 1 (2.2) | 0 (0) | ||
| Sex | Female | 94 (43.7) | 9 (20) | 8 (23.5) | 0.002 |
| Male | 121 (56.3) | 36 (80) | 26 (76.5) | ||
| Ethnicity | White | 179 (83.3) | 35 (77.8) | 25 (73.5) | 0.36 |
| Asian | 22 (10.2) | 8 (17.8) | 7 (20.6) | ||
| Black, Other | 14 (6.5) | 2 (4.4) | 2 (5.9) | ||
| BMI | Median (IQR) | 26.4 (22.3,31.1) | 29.8 (24.6,33.5) | 29.2 (26.8,32.9) | 0.02 |
| 15–19.9 | 13 (8.4) | 1 (3.7) | 0 (0.0) | 0.14 | |
| 20–24.9 | 51 (32.9) | 7 (25.93) | 5 (16.7) | ||
| 25–29.9 | 41 (26.5) | 6 (22.2) | 12 (40.0) | ||
| ≥ 30 | 50 (32.3) | 13 (48.2) | 13 (43.3) | ||
| Missing | 60 (27.9) | 18 (40.0) | 4 (11.8) | ||
| Care home resident | 63 (29.3) | 2 (4.4) | 0 (0.0) | <0.001 | |
| Pre-existing comorbidities | |||||
| Hypertension | 77 (35.8) | 20 (44.4) | 12 (35.3) | 0.54 | |
| Chronic cardiac disease | 75 (34.9) | 12 (26.7) | 3 (8.8) | 0.008 | |
| Diabetes mellitus without complications | 42 (19.5) | 8 (17.8) | 6 (17.7) | 0.94 | |
| Diabetes mellitus with complications | 13 (6.1) | 9 (20.0) | 4 (12.1) | 0.009 | |
| Dementia | 54 (25.1) | 2 (4.4) | 0 (0) | <0.001 | |
| Chronic pulmonary disease | 36 (16.7) | 9 (20.0) | 4 (11.8) | 0.62 | |
| Chronic neurological disease | 35 (16.3) | 2 (4.4) | 1 (2.9) | 0.02 | |
| Asthma | 24 (11.2) | 2 (4.4) | 8 (23.5) | 0.03 | |
| Chronic kidney disease | 23 (10.7) | 4 (8.9) | 1 (2.9) | 0.35 | |
| Rheumatological condition | 19 (8.8) | 3 (6.7) | 0 (0) | 0.19 | |
| Malignant neoplasm | 17 (7.9) | 3 (6.8) | 0 (0) | 0.24 | |
| Clinical features at admission | |||||
| Days since onset of symptoms Median (IQR) | 5 (2,9) | 7 (4,12) | 7 (6,10) | <0.001 | |
| Missing | 38 (17.7) | 2 (4.4) | 1 (2.9) | ||
| Fever | 32 (61.4) | 30 (66.7) | 28 (82.6) | 0.03 | |
| Missing | 9 (4.2) | 0 (0) | 2 (5.9) | ||
| Cough | 141 (65.6) | 39 (86.7) | 31 (91.2) | 0.002 | |
| Missing | 7 (3.3) | 0 (0) | 0 (0) | ||
| Shortness of breath | 123 (57.2) | 33 (73.3) | 25 (73.5) | 0.05 | |
| Missing | 5 (2.3) | 0 (0) | 1 (2.9) | ||
| Temperature | Median (IQR) | 36.7 (36.3,37.3) | 37.2 (36.7,37.7) | 37.4 (36.5,38.2) | <0.001 |
| Respiratory rate | Median (IQR) | 22 (19, 26) | 26 (20, 29) | 28 (24, 32) | <0.001 |
| Heart rate | Median (IQR) | 90 (74, 106) | 97 (78, 108) | 98 (86, 110) | 0.04 |
| CXR at admission | Clear5 | 51 (23.7) | 2 (4.4) | 0 (0.0) | <0.001 |
| Unilateral opacities | 35 (16.3) | 1 (2.2) | 1 (2.9) | ||
| Bilateral opacities | 129 (60.0) | 42 (93.3) | 33 (97.1) | ||
| Ceiling of care timing | Never | 83 (38.6) | 20 (44.4) | 34 (100) | |
| Pre-admission | 62 (28.8) | 1 (2.2) | - | ||
| Within 24 hours | 57 (26.5) | 18 (40.0) | - | ||
| Later during admission | 13 (6.1) | 6 (13.3) | - | ||
1Air only (N = 55), oxygen via nasal prongs (N = 72), via face mask (N = 54), via non-rebreather mask (N = 34);
2 Seven patients had CPAP with helmet and 38 had CPAP with face mask;
3 Ten patients escalated directly to IMV from air/oxygen while 24 were trialled on CPAP before IMV;
4Kruskal-Wallis equality-of-populations rank test was used to compare median values.