Table 2.
GRADE summary of findings table of primary outcomes
| Outcomes | Study design | Anticipated absolute effectsc (95% CI) | Relative effect (95% CI) | №. of participants (studies) | Certainty of the evidence (GRADE) | |
|---|---|---|---|---|---|---|
| Risk with non-prone | Risk with prone | |||||
| Non-intubated patients | ||||||
| Mortality | RCT | 224 per 1000 | 204 per 1000 (175–238) | RR 0.91 (0.78–1.06) | 2404 (8) | ⨁⨁⨁⨁ High |
| NRS | 314 per 1000 | 176 per 1000 (141–220) | RR 0.56 (0.45–0.70) | 3361 (18) | ⨁◯◯◯ Very lowa | |
| Need for intubation | RCT | 389 per 1000 | 315 per 1000 (280–351) | RR 0.81 (0.72–0.90) | 2156 (7) | ⨁⨁⨁⨁ High |
| NRS | 412 per 1000 | 267 per 1000 (206–350) | RR 0.65 (0.50–0.85) | 3374 (18) | ⨁◯◯◯ Very lowa | |
| Adverse events | RCT | 24 per 1000 | 23 per 1000 (16–34) | RR 0.97 (0.66–1.43) | 7011 (6) | ⨁⨁⨁◯ Moderateb |
| NRS | Cases in the prone group were reported as follows: desaturation or hemodynamic worsening 0/30 [34], back pain 2/30 [34] and 3/57 [42], bloating sensation 2/30 [34], gastric distension and vomit 0/81 [30], peripheral line removal 2/57 [42] and 2/81 [30], nasal skin ulceration 2/81 [30], major adverse events 0/48 [44], overall adverse events 0/17 [5] and 0/38 [46] | 716 (6) | ⨁◯◯◯ Very lowa,b | |||
| Intubated patients | ||||||
| Mortality | NRS | 525 per 1000 | 504 per 1000 (441–573) | RR 0.96 (0.84–1.09) | 995 (2) | ⨁◯◯◯ Very lowa |
| Chen et al. [38] reported better survival in prone group than in non-prone group (adjusted hazard ratio 0.282, 95% CI 0.126 to 0.63) | 40 (1) | |||||
| Adverse events | NRS | Cases in the prone group were reported as follows: endotracheal tube dislocation 0/62 [9], peripheral line removal 2/62 [9] | 261 (1) | ⨁◯◯◯ Very lowa,b | ||
GRADE Working Group grades of evidence
High certainty: we are very confident that the true effect lies close to that of the estimate of the effect
Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different
Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect
Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect
CI, confidence interval; RR, risk ratio; RCT, randomized controlled trial; NRS, nonrandomized studies
aDowngrade for risk-of-bias concern in the domains of possibility of target group comparisons, target group selection, and confounder
bNo more than 300 events
cThe risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI)