| Study | Reason for exclusion |
|---|---|
| Agnelli 1995 | Trial participants did not suffer from VTE as initial event. |
| Alhenc‐Gelas 1994 | Did not compare once daily against twice daily treatment with LMWH. |
| Andersen 1997 | Did not compare once daily against twice daily treatment with LMWH. |
| Bara 1992 | Did not compare once daily against twice daily treatment with LMWH. |
| Beckman 2003 | Did not compare once daily against twice daily treatment with LMWH. |
| Belcaro 1999 | Did not compare once daily against twice daily treatment with LMWH. |
| Bellosta 2007 | Used different LMWH, with once daily versus twice daily for one month only and following that, the twice daily treatment arm reverted to once daily prophylactic dose. This makes comparing once daily versus twice daily regimens untenable as there were no results for effectiveness of the regimens at one month. |
| Boneu 1998 | Trial participants did not suffer from VTE as initial event. |
| Bratt 1988 | Did not compare once daily against twice daily treatment with LMWH. |
| Bratt 1990 | Trial participants did not suffer from VTE as initial event. |
| Breddin 2001 | Patients treated with LMWH once daily received a vitamin K antagonist from day 21 onwards, while for those treated with LMWH twice daily, administration of vitamin K antagonists was started at day one. |
| Breddin 2003 | Patients treated with LMWH once daily received a vitamin K antagonist from day 21 onwards, while for those treated with LMWH twice daily, administration of vitamin K antagonists was started at day one. |
| Buller 2004 | Did not compare once daily against twice daily treatment with LMWH. |
| Cosmi 2012 | Superficial vein thrombosis not DVT. The study compared different doses of LMWH and not once versus twice daily regimens. |
| Erikson 2002 | Trial participants did not suffer from VTE as initial event. |
| Erikson 2003 | Trial participants did not suffer from VTE as initial event. |
| Fiessinger 1996 | Did not compare once daily against twice daily treatment with LMWH. |
| Harenberg 1990 | Did not compare once daily against twice daily treatment with LMWH. |
| Harenberg 1997 | Did not compare once daily against twice daily treatment with LMWH. |
| Holmström 1997 | Did not compare once daily against twice daily treatment with LMWH. |
| Hull 1997 | Did not compare once daily against twice daily treatment with LMWH. |
| Hull 2000a | Did not compare once daily against twice daily treatment with LMWH. |
| Hull 2000b | Did not compare once daily against twice daily treatment with LMWH. |
| Kakkar 2002 | Patients treated with LMWH once daily received a vitamin K antagonist from day 21 onwards, while for those treated with LMWH twice daily, administration of vitamin K antagonists was started at day one. |
| Leizorovicz 2011 | Did not compare once daily against twice daily treatment with LMWH. Compared once daily LMWH with twice daily heparin for acute treatment of DVT in elderly patients with renal impairment. |
| Leroyer 1998 | Did not compare once daily against twice daily treatment with LMWH. |
| Lindmarker 1994 | Did not compare once daily against twice daily treatment with LMWH. |
| Luomanmaki 1996 | Did not compare once daily against twice daily treatment with LMWH. |
| Meyer 1995 | Did not compare once daily against twice daily treatment with LMWH. |
| Mismetti 1995 | Trial participants did not suffer from VTE as initial event. |
| Narin 2008 | Retrospective study involving treatment of DVT in pregnant patients. Initial treatment involved unfractionated heparin for five days before starting LMWH. |
| Offord 2004 | Did not compare once daily against twice daily treatment with LMWH. |
| Petilla 2002 | Trial participants did not suffer from VTE as initial event. |
| Pini 1994 | Did not compare once daily against twice daily treatment with LMWH. |
| Sandset 1990 | Did not compare once daily against twice daily treatment with LMWH. |
| Schellong 2010 | Did not compare once daily against twice daily treatment with LMWH. |
| Simonneau 1993 | Did not compare once daily against twice daily treatment with LMWH. |
| Simonneau 1997 | Did not compare once daily against twice daily treatment with LMWH. |
| Stricker 1999 | Did not compare once daily against twice daily treatment with LMWH. |
| Turpie 2002 | Trial participants did not suffer from VTE as initial event. |
| Wartski 2000 | Did not compare once daily against twice daily treatment with LMWH. |
DVT: deep vein thrombosis LMWH: low molecular weight heparin VTE: venous thromboembolism