Table 1 Summary of design characteristics for the 14 selected studies
Study | Patient population | Acute therapy | Long-term therapy | Experimental treatment duration | Window for analysis of recurrent VTE |
|---|---|---|---|---|---|
Barritt [7] | PE | Intravenous UFH q6h vs placebo | VKA. PT 2.0–3.0 times control vs placebo | 14 days | 3 months |
Hull [8] | DVT | Intravenous UFH | VKA started on day 10, PT 1.5–2.0 vs subcutaneous UFH bid | 6 weeks for calf DVT and 12 weeks for proximal DVT | 3 months |
Holmgren [9] | DVT | UFH | VKA started on day 1, TT 5–14% | 1 month vs 6 months | 3 months |
Lagerstedt [10] | Isolated calf DVT | Intravenous UFH | VKA started on day 1, INR 2.5–4.2 vs placebo | 3 months | 3 months |
Hull [11] | Proximal DVT | Intravenous UFH vs subcutaneous UFH | VKA started on day 6 or 7, INR 2.0–3.0 | 3 months | 3 months |
Brandjes [12] | Proximal DVT | Intravenous UFH vs placebo | VKA started on day 1, INR 2.0–3.0 | 6 months | 3 months |
Raschke [13] | DVT or PE | Intravenous weight-based UFH vs ‘standard care’ UFH nomogram | VKA started after day 2 | Not specified or monitored | 3 months |
Levine [14] | Proximal DVT | Intravenous UFH | VKA INR 2.0–3.0 vs placebo | 4 weeks vs 12 weeks | 3 months |
Schulman [15] | DVT or PE | Intravenous UFH or subcutaneous LMWH | VKA started on day 1, INR 2.00–2.85 | 6 weeks vs 6 months | 3 months |
Agnelli [16] | Idiopathic proximal DVT | Intravenous UFH or subcutaneous LMWH | VKA INR 2.0–3.0 vs no treatment | Months 4–12 vs no treatment | Months 4–12 |
Agnelli [17] | PE | Intravenous UFH or subcutaneous LMWH | VKA INR 2.0–3.0 vs no treatment | Months 4–12 vs no treatment | Months 4–12 |
Kearon [18] | Idiopathic DVT or PE | Intravenous UFH or subcutaneous LMWH | VKA INR 2.0–3.0 vs placebo | Months 4–24 vs no treatment | Months 4–24 |
Pinede [19] | DVT or PE | Intravenous UFH or subcutaneous LMWH | VKA INR 2.0–3.0 | Months 4–6 vs no treatment | Months 4–6 |
Schulman [20] | First recurrent DVT or PE | Intravenous UFH or subcutaneous LMWH | VKA INR 2.00–2.85 vs no treatment | Indefinitely vs none | Month 6 onwards |