Summary of findings of thromboprophylaxis in cancer patients with intermediate, intermediate to high, or high risk of VTE according to Khorana score
| Study outcome at 6 mo . | No. of patients (RCTs) . | Certainty of evidence (GRADE) . | RR (95% CI) . | Anticipated absolute effects . | ||
|---|---|---|---|---|---|---|
| Risk without thromboprophylaxis, %* . | Risk difference with thromboprophylaxis (95% CI), % . | NNT/NNH . | ||||
| Intermediate to high risk of VTE (Khorana score ≥2) | ||||||
| VTE | 4626 (6) | ⨁⨁⨁⨁ (high) | 0.51 (0.34-0.67) | 8.3 | −4.1 (−5.5 to −2.7) | NNT, 25 (19-38) |
| Major bleeding | 4583 (6) | ⨁⨁⨁◯ (moderate)† | 1.06 (0.69-1.67) | 1.8 | 0.1 (−0.6 to 1.2) | NNH, 1000 (NNH 84 to ∞ to NNT 167) |
| All-cause mortality | 4626 (6) | ⨁⨁⨁◯ (moderate)† | 0.90 (0.82-1.01) | 28.4 | −2.8 (−5.1 to 0.3) | NNT, 36 (NNT 20 to ∞ to NNH 334) |
| Intermediate risk of VTE (Khorana score 2) | ||||||
| VTE | 2837 (6) | ⨁⨁⨁⨁ (high) | 0.58 (0.36-0.83) | 7.1 | −3.0 (−4.5 to −1.2) | NNT, 34 (23-84) |
| Major bleeding | 2806 (6) | ⨁⨁⨁◯ (moderate)† | 0.88 (0.45-2.30) | 1.4 | −0.2 (−0.8 to 1.8) | NNT, 500 (NNT 125 to ∞ to NNH 56) |
| All-cause mortality | 1894 (4) | ⨁⨁⨁◯ (moderate)† | 0.90 (0.74-1.04) | 28.8 | −2.9 (−7.5 to 1.2) | NNT, 35 (NNT 14 to ∞ to NNH 84) |
| High risk of VTE (Khorana score ≥3) | ||||||
| VTE | 1781 (6) | ⨁⨁⨁⨁ (high) | 0.45 (0.28-0.67) | 11.1 | −6.1 (−8.0 to −3.7) | NNT, 17 (13-28) |
| Major bleeding | 1770 (6) | ⨁⨁⨁◯ (moderate)† | 1.11 (0.64-1.92) | 2.5 | 0.3 (−0.9 to 2.3) | NNH, 334 (NNH 44 to ∞ to NNT 112) |
| All-cause mortality | 1326 (4) | ⨁⨁⨁◯ (moderate)† | 0.91 (0.68-1.24) | 38.6 | −3.5 (−12.3 to 9.3) | NNT, 29 (NNT 9 to ∞ to NNH 11) |
| Study outcome at 6 mo . | No. of patients (RCTs) . | Certainty of evidence (GRADE) . | RR (95% CI) . | Anticipated absolute effects . | ||
|---|---|---|---|---|---|---|
| Risk without thromboprophylaxis, %* . | Risk difference with thromboprophylaxis (95% CI), % . | NNT/NNH . | ||||
| Intermediate to high risk of VTE (Khorana score ≥2) | ||||||
| VTE | 4626 (6) | ⨁⨁⨁⨁ (high) | 0.51 (0.34-0.67) | 8.3 | −4.1 (−5.5 to −2.7) | NNT, 25 (19-38) |
| Major bleeding | 4583 (6) | ⨁⨁⨁◯ (moderate)† | 1.06 (0.69-1.67) | 1.8 | 0.1 (−0.6 to 1.2) | NNH, 1000 (NNH 84 to ∞ to NNT 167) |
| All-cause mortality | 4626 (6) | ⨁⨁⨁◯ (moderate)† | 0.90 (0.82-1.01) | 28.4 | −2.8 (−5.1 to 0.3) | NNT, 36 (NNT 20 to ∞ to NNH 334) |
| Intermediate risk of VTE (Khorana score 2) | ||||||
| VTE | 2837 (6) | ⨁⨁⨁⨁ (high) | 0.58 (0.36-0.83) | 7.1 | −3.0 (−4.5 to −1.2) | NNT, 34 (23-84) |
| Major bleeding | 2806 (6) | ⨁⨁⨁◯ (moderate)† | 0.88 (0.45-2.30) | 1.4 | −0.2 (−0.8 to 1.8) | NNT, 500 (NNT 125 to ∞ to NNH 56) |
| All-cause mortality | 1894 (4) | ⨁⨁⨁◯ (moderate)† | 0.90 (0.74-1.04) | 28.8 | −2.9 (−7.5 to 1.2) | NNT, 35 (NNT 14 to ∞ to NNH 84) |
| High risk of VTE (Khorana score ≥3) | ||||||
| VTE | 1781 (6) | ⨁⨁⨁⨁ (high) | 0.45 (0.28-0.67) | 11.1 | −6.1 (−8.0 to −3.7) | NNT, 17 (13-28) |
| Major bleeding | 1770 (6) | ⨁⨁⨁◯ (moderate)† | 1.11 (0.64-1.92) | 2.5 | 0.3 (−0.9 to 2.3) | NNH, 334 (NNH 44 to ∞ to NNT 112) |
| All-cause mortality | 1326 (4) | ⨁⨁⨁◯ (moderate)† | 0.91 (0.68-1.24) | 38.6 | −3.5 (−12.3 to 9.3) | NNT, 29 (NNT 9 to ∞ to NNH 11) |
Risk of VTE in intervention group (and its 95% CI) is based on assumed risk in comparison group and relative effect of intervention (and its 95% CI). Assumed risk is derived from systematic review on VTE incidences with different Khorana scores by Mulder et al.17
Downgraded for imprecision because of possible positive and negative effects of thromboprophylaxis vs control.