Summary of findings for the main comparison. Prophylactic platelet transfusion at threshold of 10,000 compared to higher transfusion threshold (20,000 or 30,000) for people with a haematological disorder.
| Prophylactic platelet transfusion at threshold of 10,000 compared to higher transfusion threshold (20,000 or 30,000) for prevention of haemorrhage after chemotherapy and stem cell transplantation | ||||||
| Patient or population: People with a haematological disorder Settings: Receiving intensive chemotherapy or a stem cell transplant Intervention: Prophylactic platelet transfusion at threshold of 10 x 109/L Comparison: Higher transfusion threshold (20 x 109/L or 30 x 109/L) | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of Participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
|
Higher transfusion threshold (20 x 109/L or 30 x 109/L) |
Prophylactic platelet transfusion at threshold of 10 x 109/L | |||||
| Numbers of participants with at least 1 clinically significant bleeding event up to 30 days from study entry | 177 per 1000 | 239 per 1000 (168 to 336) | RR 1.35 (0.95 to 1.9) | 499 (3 studies) | ⊕⊕⊝⊝ low1,2 | The definition of clinically significant bleeding varied between studies, because there were differences in the way bleeding was graded |
| Number of days on which clinically significant bleeding occurred per participant up to 30 days from study entry | Not estimable3 | Not estimable3 | Not estimable3 | 255 (1 study) |
⊕⊕⊝⊝ low1,2 | ‐ |
| Number of participants with WHO Grade 3 or 4 bleeding up to 30 days from study entry | 82 per 1000 |
81 per 1000 (43 to 154) |
RR 0.99 (0.52 to 1.88) |
421 (2 studies) |
⊕⊕⊝⊝ low1,2 | ‐ |
| Time to first bleeding episode (days) | ‐ | ‐ |
HR 1.11 (0.64 to 1.91) |
255 (1 study) |
⊕⊕⊝⊝ low1,2 | ‐ |
| Number of platelet transfusions per participant up to 30 days from study entry | The mean number of platelet transfusions per participant in the 10 x 109/L group was 2.09 lower (3.2 to 0.99 lower) | ‐ | 333 (2 studies) | ⊕⊕⊝⊝ low1,2 | ‐ | |
| Mortality from all causes up to 30 days from study entry | 75 per 1000 |
134 per 1000 (62 to 286) |
RR 1.78 (0.83 to 3.81) |
255 (1 study) |
⊕⊕⊝⊝ low1,2 | ‐ |
| Quality of life ‐ not reported | Not estimable | Not estimable | Not estimable | ‐ | See comment | None of the studies reported quality of life |
| *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; HR: Hazard ratio; 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. | ||||||
1The number of participants from all three studies may not be large enough to detect a clinically significant difference. The confidence intervals are wide, and therefore there is uncertainty about the result. The level of evidence was downgraded by 1 due to imprecision.
2All of the studies were at high risk of bias due to lack of blinding and more protocol deviations in the standard‐trigger arm (10 x 109/L). The Rebulla study did not perform an intention‐to‐treat analysis and excluded 2 participants who died within 24 hours of entering the study. The level of evidence was downgraded by 1 due to risk of bias.
3The authors of Rebulla 1997 reported a relative proportion of days with WHO Grade 2 or worse bleeding of 1.71 (95% CI 0.84 to 3.48) for the standard versus higher transfusion trigger arms. A permutation test for the comparison of these proportions gives a P value of 0.162, and therefore no significant difference between study arms was found. These results are the authors' own results.