Fiessinger 1996.

Methods	Study design: randomised controlled trial. Method of randomisation: not stated. Concealment of allocation: not blinded for treatment allocation, blinded for outcome assessment. Exclusions post‐randomisation: 10 participants in dalteparin group and 5 participants in UFH group did not have DVT. Lost to follow‐up: 32 participants (13 versus 19) did not have a second phlebogram; 2 (1 versus 1) participants were considered not to have DVT; 20 participants (8 versus 12) were incorrectly included.
Participants	Country: Austria, France, Spain and Sweden (16 centres). Setting: hospital. No.: 253 participants. Age: mean 61 years. Sex: 115 males. Inclusion criteria: distal and/or proximal DVT with 8 or more days of symptoms. Exclusion criteria: clinical signs suggestive of PE; history of recent DVT (< 1 year) or sequelae of a previous DVT in the same leg; treatment with therapeutic doses of UFH or LMWH prior to randomisation; malignant hypertension; renal or hepatic insufficiency; platelet count < 100 x 10⁹/litre; known hypersensitivity to contrast media; surgery within 5 days of starting treatment; intracerebral bleeding in previous 2 months, gastrointestinal bleeding in previous 2 weeks; pregnancy/lactation.
Interventions	Treatment: LMWH: 1 mL active substance equivalent to 10,000 anti‐factor Xa IU (Dalteparin, Fragmin) s.c. injection (200 IU/kg) o.d.. Bolus dose of 5000 IU. s.c. if randomisation before phlebography, otherwise a first full‐dose. Control: UFH: before phlebography: bolus dose of 5000 IU i.v. followed by continuous i.v. infusion of 20,000 to 40,000 IU/24 hours APTT‐adjusted (1.5 to 3.0 ×). After phlebography a bolus i.v. injection administered prior to infusion of UFH at discretion of attending physician. Treatment duration: 5 to 10 days, when the prothrombin time (INR) was within therapeutic range (2 to 3) on 2 consecutive days. Oral anticoagulation: started on day of inclusion or day after. Period determined by attending physician; mean period of treatment 5.3 months in both groups.
Outcomes	Primary: change in thrombus size (Marder's score); recurrent VTE during initial treatment (prospective follow‐up) and at the end of 6 months' follow‐up; PE during initial treatment and at the end of 6 months' follow‐up. Secondary: major haemorrhage during initial treatment; mortality; mortality in participants with malignancy at entry.
Notes	20 participants not correctly included; 32 participants without second phlebography. Follow‐up: 6 months, but 23 participants lost to follow‐up; of these 13 were alive.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information.
Allocation concealment (selection bias)	Unclear risk	Insufficient information.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Not blinded for treatment allocation. Comment: given the clinical outcomes of the study, review authors judged that the non‐blinding of the participants and staff was unlikely to have affected the outcomes.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcome assessment was blinded and the non‐blinding of others is unlikely to introduce bias.
Incomplete outcome data (attrition bias) All outcomes	High risk	Missing outcome data imbalanced in numbers across intervention groups.
Selective reporting (reporting bias)	Unclear risk	Insufficient information.
Other bias	Low risk	The study appears to be free of other sources of bias.