for the main comparison.
| Restrictive compared with liberal transfusion protocols for guiding allogeneic red blood cell transfusion | ||||||
|
Patient or population: Adults and children (haemodynamically stable) with potential need for RBC transfusion Settings: Inpatient Intervention: Restrictive transfusion protocol Comparison: Liberal transfusion protocol | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Liberal transfusion (Hb 9 g/dL to 10 g/dL) | Restrictive transfusion (Hb 7 g/dL to 8 g/dL) | |||||
| People receiving blood transfusions | 841 per 1000 | 479 per 1000 | RR 0.57 (0.49 to 0.65) | 12,587 (31) | ⊕⊕⊕⊕ High | ‐ |
| 30‐day mortality | 93 per 1000 | 90 per 1000 | RR 0.97 (0.81 to 1.16) | 10,537 (23) | ⊕⊕⊕⊝ Moderatea | ‐ |
| Myocardial infarction | 17 per 1000 | 19 per 1000 | RR 1.08 (0.74 to 1.60) | 8303 (16) | ⊕⊕⊕⊕ High | ‐ |
| Congestive heart failure | 36 per 1000 | 28 per 1000 | RR 0.78 (0.45 to 1.35) | 6257 (12) | ⊕⊕⊝⊝ Lowb,c | ‐ |
| Cerebrovascular accident (CVA) ‐ stroke | 17 per 1000 | 13 per 1000 | RR 0.78 (0.53 to 1.14) | 7343 (13) | ⊕⊕⊕⊕ High | ‐ |
| Rebleeding | 163 per 1000 | 144 per 1000 | RR 0.75 (0.51 to 1.10) | 3108 (6) | ⊕⊕⊝⊝ Lowd, e | ‐ |
| Pneumonia | 82 per 1000 | 76 per 1000 | RR 0.94 (0.80 to 1.11) | 6277 (14) | ⊕⊕⊕⊕ High | ‐ |
| Thromboembolism | 10 per 1000 | 8 per 1000 | RR 0.77 (0.41 to 1.45) | 4019 (10) | ⊕⊕⊕⊕ High | ‐ |
| *The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (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). CI: confidence interval; RBC: red blood cell;RR: risk ratio | ||||||
| GRADE Working Group grades of evidence High quality: further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: we are very uncertain about the estimate. | ||||||
a. Downgraded for imprecision: could be up to 17 per 1000 more deaths in restrictive transfusion. b. Downgraded for inconsistency: moderately wide confidence intervals. c. Downgraded for risk of bias: blinding of participants and personnel impossible and blinding of outcome assessment inconsistent between trials. d. Downgraded for inconsistency: I² = 58%, P = 0.04. e. Downgraded for imprecision: could be up to 16 per 1000 more rebleeds in restrictive transfusion.