Lopaciuk 1992.

Methods	Study design: randomised controlled trial. Method of randomisation: sealed envelopes, stratified for site of DVT. Concealment of allocation: not blinded for treatment allocation, blinded for outcome assessment. Exclusions post‐randomisation: 3 participants in UFH group judged to be ineligible (2 with recent history of DVT and 1 deficient in antithrombin III). Lost to follow‐up: 6 in LMWH group and 6 in UFH group (poor phlebogram, 6; absent phlebogram, 4; protocol violation (treatment for 15 days), 1; major bleeding with treatment cessation, 1).
Participants	Country: Poland (6 centres). Setting: hospital. No.: 149 participants of which 117 participants had proximal DVT. Age: mean 48 years. Sex: 81 males. Inclusion criteria: symptomatic proximal or calf DVT (phlebographically proven). Exclusion criteria: clinically suspected PE; phlegmasia caerulea dolens; treatment with heparin or oral anticoagulants prior to admission; history of VTE in previous 2 years; surgery or trauma within previous 3 days; contraindication to heparin therapy; pregnancy; documented antithrombin III deficiency.
Interventions	Treatment: LMWH: fraxiparine fixed dose: 92 anti‐factor Xa IU/kg, s.c., twice daily Control: UFH: initial i.v. bolus of 5000 IU followed by 250 IU/kg s.c., twice daily; dose‐adjusted APTT × 1.5 to 2.5 s.c. Treatment duration: 10 days. Oral anticoagulation: acenocoumarol started on day 7 and continued for at least 3 months; INR 2.0 to 3.0.
Outcomes	Primary: change in thrombus size (Arnesen score); recurrent DVT; PE. Secondary: major and minor haemorrhage; mortality; mortality in participants with malignant disease.
Notes	Proximal DVT: 58 (LMWH) versus 59 (UFH). Distal DVT: 16 (LMWH) versus 13 (UFH). 12 participants excluded from repeated venography analysis. Follow‐up: 3 months.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information.
Allocation concealment (selection bias)	Low risk	Sealed envelopes were used.
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	Blind evaluation of phlebographic results.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Missing outcome data balanced in numbers across intervention groups.
Selective reporting (reporting bias)	Unclear risk	Insufficient information.
Other bias	High risk	There was an imbalanced exclusion at baseline.