Summary of findings for the main comparison. Is unfractionated heparin (UFH) use better than low molecular weight heparin (LMWH) use to avoid heparin‐induced thrombocytopenia?
| Is unfractionated heparin (UFH) use better than low molecular weight heparin (LMWH) use to avoid heparin‐induced thrombocytopenia? | ||||||
| Patient or population: people undergoing surgical procedures and treated with UFH or LMWH for prophylaxis of thrombotic events lasting at least 5 days Setting: hospital Intervention: LMWH Comparison: UFH | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Risk with UFH | Risk with LMWH | |||||
| Heparin‐induced thrombocytopenia (HIT) Follow‐up: range 10 days to 14 days, or until discharge |
Study population | RR 0.23 (0.07 to 0.73) | 1398 (3 RCTs) | ⊕⊕⊝⊝ Low1, 2 | ||
| 22 per 1000 | 5 per 1000 (2 to 16) | |||||
| HIT in people undergoing major surgical procedures Follow‐up: range 10 days to 14 days, or until discharge |
Study population | RR 0.22 (0.06 to 0.75) | 586 (2 RCTs) | ⊕⊕⊝⊝ Low1, 2 | ||
| 48 per 1000 | 11 per 1000 (3 to 36) | |||||
| HIT complicated by venous thromboembolism Follow‐up: range 10 days to 14 days, or until discharge |
Study population | RR 0.22 (0.06 to 0.84) | 1398 (3 RCTs) | ⊕⊕⊝⊝ Low1, 2 | ||
| 17 per 1000 | 4 per 1000 (1 to 14) | |||||
| *The 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) CI: Confidence interval; HIT: heparin‐induced thrombocytopenia;LMWH: low molecular weight heparin; RR: Risk ratio; UFH: unfractionated heparin | ||||||
| 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 | ||||||
1Downgraded by one level due to high risk and unclear risk of bias in the domains: selection bias, performance bias, detection and attrition bias. 2Downgraded by one level due to imprecision: small number of events and due to the fact that trials included in the analysis were underpowered to detect HIT.