Summary of findings 6. Vitamin K antagonist (VKA) compared to low molecular weight heparin (LMWH) for ambulatory patients with multiple myeloma receiving immunomodulatory agents: 2 years follow‐up.
| Vitamin K antagonist (VKA) compared to low molecular weight heparin (LMWH) for ambulatory patients with multiple myeloma receiving immunomodulatory agents: 2 years follow‐up | |||||
| Population: ambulatory patients with multiple myeloma receiving immunomodulatory agents Setting: outpatient Intervention: VKA prophylaxis Control: LMWH prophylaxis | |||||
| Outcomes | № of participants (studies) | Certainty of the evidence (GRADE) | Relative effect (95% CI) | Anticipated absolute effects* (95% CI) | |
| Risk with LMWH | Risk difference with VKA | ||||
| All‐cause mortality follow‐up: 2 years | 440 (1 RCT) | ⊕⊝⊝⊝ VERY LOW 1 2 | RR 2.00 (0.18 to 21.90) | Study population | |
| 5 per 1000 | 5 more per 1000 (4 fewer to 95 more) | ||||
| Symptomatic deep vein thrombosis follow‐up: 2 years | 440 (1 RCT) | ⊕⊝⊝⊝ VERY LOW 1 3 | RR 1.70 (0.80 to 3.63) | Study population | |
| 45 per 1000 | 32 more per 1000 (9 fewer to 120 more) | ||||
| Pulmonary embolism follow‐up: 2 years | 440 (1 RCT) | ⊕⊝⊝⊝ VERY LOW 1 4 | RR 9.00 (0.49 to 166.17) | Low | |
| 1 per 1000 5 | 8 more per 1000 (1 fewer to 165 more) | ||||
| Major bleeding ‐ not reported | ‐ | ‐ | ‐ | ‐ | ‐ |
| Minor bleeding ‐ not reported | ‐ | ‐ | ‐ | ‐ | ‐ |
| *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; RCT: randomised controlled trial; RR: risk ratio | |||||
| 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. | |||||
1Downgraded by one level due to serious risk of bias. Lack of blinding of participants and personnel and selective reporting (all outcomes listed in the methods section were reported on except for secondary endpoint related to any toxicity that required interruption of study prophylaxis). 2Downgraded by two levels due to concerns about imprecision; 95% CI is consistent with the possibility of no effect (4 per 1000 absolute reduction) and the possibility of important harm (95 per 1000 absolute increase), including four events in total. 3Downgraded by two levels due to concerns about imprecision; 95% CI is consistent with the possibility of benefit (9 per 1000 absolute reduction) and the possibility of important harm (120 per 1000 absolute increase), including 27 events in total. 4Downgraded by two levels due to concerns about imprecision; 95% CI is consistent with the possibility of no effect (1 per 1000 absolute reduction) and the possibility of important harm (165 per 1000 absolute increase), including four events in total. Given the observed baseline risk of 0%, we used 0.1% to generate an absolute effect and a confidence interval. 5There were no events in the control arm.