Comparison of PREHOSPITAL primary and secondary outcomes by treatment group (N=708)
| Outcomes | Usual care (n=346) | Missing, n (%) | CPAP (n=362) | Missing, n (%) | % difference (95% CI) | Median difference (95% CI) | P value* |
| Primary outcomes | |||||||
| Dyspnoea VAS score | |||||||
| First, median (IQR) | 9.0 (8.0 to 10.0) | 23 (6.6) | 9.0 (8.0 to 10.0) | 20 (5.5) | 0 (0 to 0) | 0.21 | |
| Pre-ED arrival, median (IQR) | 7.0 (5.0 to 8.8) | 32 (9.2) | 5.0 (3.0 to 7.0) | 25 (6.9) | −2.0 (−2.0 to −1.5) | <0.001 | |
| Change (PreED-First), median (IQR) | −1.0 (−3.0 to 0.0) | 32 (9.2) | −3.5 (−5.2 to −2.0) | 25 (6.9) | −2.0 (−2.5 to −1.6) | <0.001 | |
| RR | |||||||
| First, median (IQR) | 38.0 (32.0 to 42.0) | 0 | 40.0 (32.0 to 45.0) | 0 | 2.0 (0.0 to 3.0) | 0.007 | |
| Pre-ED arrival, median (IQR) | 32.0 (28.0 to 40.0) | 0 | 28.0 (24.0 to 36.0) | 2 (0.6) | −2.0 (−4.0 to −2.0) | <0.001 | |
| Change (PreED-First), median (IQR) | −4.0 (−9.0 to 0.0) | 0 | −8.0 (−14.0 to −4.0) | 2 (0.6) | −4.0 (−5.0 to −4.0) | <0.001 | |
| RR >30 (First), n (%) | 290 (83.8) | 0 | 319 (88.1) | 0 | 4.3 (−0.8 to 9.4) | 0.10 | |
| RR >30 (PreED), n (%) | 222 (64.2) | 0 | 168 (46.7) | 2 (0.6) | −17.5 (−24.7 to −10.3) | <0.001 | |
| Secondary outcomes | |||||||
| Oxygen saturation (SpO2) | |||||||
| First, median (IQR) | 85.0 (78.0 to 90.0) | 0 (0.0) | 84.0 (76.0 to 90.0) | 2 (0.6) | −1.0 (−3.0 to 0.0) | 0.08 | |
| Pre-ED arrival, median (IQR) | 97.0 (93.0 to 99.0) | 2 (0.6) | 97.0 (93.0 to 100.0) | 4 (1.1) | 0.0 (0.0 to 1.0) | 0.40 | |
| Change (PreED-First), median (IQR) | 10.0 (5.0 to 17.0) | 2 (0.6) | 11.0 (7.0 to 18.0) | 4 (1.1) | 2.0 (0.0 to 3.0) | 0.01 | |
| Time from arrival at scene to arrival at ED (min), median IQR | 35.0 (28.0 to 42.0) | 0 | 37.0 (31.0 to 46.0) | 0 | 3.0 (1.0 to 4.0) | 0.001 | |
| Priority 1 transport to hospital, n (%) | 133 (38.6) | 1 (0.3) | 175 (48.6) | 2 (0.6) | 10.0 (2.7 to 17.3) | 0.01 | |
| Death within 30 days, n (%) | 52 (15.0) | 0 | 58 (16.0) | 0 | 1.0 (–4.3 to 6.3) | 0.72 |
*Mann-Whitney test for continuous variables, and Pearson’s χ2 test for categorical variables.
CPAP, continuous positive airway pressure; SpO2, peripheral capillary oxygen saturation; VAS, Visual Analogue Scale.