Summary of findings for the main comparison. Long‐term RBC transfusion compared to standard care for prevention of SCI in people with SCD and normal TCD velocities.
| Long‐term RBC transfusion compared to standard care for prevention of SCI in people with SCD and normal TCD velocities | ||||||
| Patient or population: prevention of SCI in people with SCD and normal TCD velocities Setting: outpatients Intervention: long‐term RBC transfusion Comparison: standard care | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Risk with standard care | Risk with long‐term RBC transfusion | |||||
| Proportion of participants developing new or progressive SCI lesions | Trial population | RR 0.70 (0.23 to 2.13) | 196 (1 RCT) | ⊕⊕⊝⊝ LOW 1 2 | ||
| 72 per 1000 | 51 per 1000 (17 to 154) | |||||
| All‐cause mortality | No deaths occurred in either trial arm | ‐ | 196 (1 RCT) | ⊕⊕⊝⊝ LOW 1 3 | ||
| SCD ‐ related SAEs ‐ ACS | Trial population | RR 0.20 (0.08 to 0.51) | 196 (1 RCT) | ⊕⊕⊝⊝ LOW 1 4 | ||
| 247 per 1000 | 49 per 1000 (20 to 126) | |||||
| SCD‐related SAEs ‐ pain crisis | Trial population | RR 0.56 (0.40 to 0.78) | 196 (1 RCT) | ⊕⊕⊝⊝ LOW 1 4 | ||
| 577 per 1000 | 323 per 1000 (231 to 450) | |||||
| Clinical stroke | Trial population | RR 0.14 (0.02 to 1.12) | 196 (1 RCT) | ⊕⊕⊝⊝ LOW 1 2 | ||
| 72 per 1000 | 10 per 1000 (1 to 81) | |||||
| Cognitive function assessed with: WASI IQ score | Least square mean 1.7 (SE 95% CI ‐1.1 to 4.4) | ‐ | 196 (1 RCT) | ⊕⊕⊝⊝ LOW 1 4 | Author reported data from SIT 2014 | |
| Quality of life assessed with: Child Health Questionnaire Parent Form 50 | Least square mean 1.7 (SE 95% CI ‐1.1 to 4.4) Diference estimate ‐0.54 (‐0.92 to ‐0.17) | ‐ | 196 (1 RCT) | ⊕⊕⊝⊝ LOW 1 4 | Author reported data from SIT 2014 | |
| *The risk in the intervention group (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). ACS: acute chest syndrome; CI: confidence interval; RR: risk ratio; RBC: red blood cell; RCT: randomised controlled trial; SAEs: serious adverse events; SCD: sickle cell disease; SCI: silent cerebral infarcts; SE: standard error; TCD: transcranial doppler | ||||||
| GRADE Working Group grades of evidence High quality: we are very confident that the true effect lies close to that of the estimate of the effect Moderate quality: 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 quality: our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect Very low quality: we have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect | ||||||
1 We downgraded the quality of evidence by 1 due to indirectness. Only children with HbSS or HbSβº thalassaemia included. If this review was only considering the quality of evidence for children with HbSS the quality of evidence would not have been downgraded for indirectness.
2 We downgraded the quality of evidence by 1 due to imprecision. The estimate has wide confidence intervals that include clinically relevant benefit and harm
3 We downgraded the quality of evidence by 1 due to imprecision. Rare event, no deaths occurred
4 We downgraded the quality of evidence by 1 due to high risk of bias. Performance bias, unblinded outcome assessment and high cross‐over rates