Table 3 Confidence in the relative risk of each comparison and outcome assessed by the GRADE system for short-term mortality and intubation
| Risk of bias across studies | Imprecision | Heterogeneity | Indirectness | Publication bias | Incoherence | Confidence in relative risk of the event | |
|---|---|---|---|---|---|---|---|
| Short-term mortality | |||||||
| NPPV vs. COT | Undetected |
Not serious (95% CI 0.76-1.01) |
Major concern a) (95% PI 0.49-1.45) | Low | Not suggested |
Major concernb (p = 0.005) | ⨁⨁◯◯ Low |
| HFNC vs. COT | Undetected |
Not serious (95% CI 0.80-1.08) |
Major concern a) (95% PI 0.45-1.47) | Low | Not suggested |
Major concernb (p = 0.031) | ⨁⨁◯◯ Low |
| HFNC vs. NPPV | Undetected |
Not serious (95% CI 0.78-1.15) |
Major concern a) (95% PI 0.56-1.91) | Low | Not suggested |
Major concernb (p < 0.001) | ⨁⨁◯◯ Low |
| Intubation | |||||||
| NPPV vs. COT | Undetected |
Not serious (95% CI 0.72-0.91) |
Major concern a) (95% PI 0.29-1.46) | Low | Not suggested |
Major concernb (p = 0.0035) | ⨁⨁◯◯ Low |
| HFNC vs. COT | Undetected |
Not serious (95% CI 0.68-0.89) |
Major concern a) (95% PI 0.26-1.44) | Low | Not suggested |
Major concernb (p = 0.001) | ⨁⨁◯◯ Low |
| HFNC vs. NPPV | Undetected |
Not serious (95% CI 0.88-1.22) |
Major concern a) (95% PI 0.45-2.49) | Low | Not suggested |
Major concernb (p < 0.001) | ⨁⨁◯◯ Low |