Kolb 2003.

Methods	Study design: Randomised, double blind, placebo controlled trial Country: Germany and Czech Republic Setting: Multicentre (13 centres), hospital and home Intention‐to‐treat: Yes and per‐protocol For the purposes of our analyses we used all participants randomised, as reported by the study authors
Participants	Number randomised: Total n = 310 (extended LMWH n = 161; placebo n = 149) Exclusions post randomisation: Total n = 37: protocol violation: 8, adverse events:10, withdrawal of consent: 19 Losses to follow up: None Age mean years (SD): Extended LMWH 78.1 (8.4); placebo 75.8 (8.4) Sex M/F: Extended LMWH 25/136; placebo 29/120 Inclusion criteria: Participants undergoing endoprosthetic joint replacement or osteosynthesis of the lower limb Exclusion criteria: Age under 18 years; hypersensitivity against heparin; clinical conditions with increased risk of bleeding; haemorrhagic diathesis; platelet count < 100.000/ul; concomitant treatment with anticoagulants or platelet inhibitors; renal or hepatic insufficiency; hypertension with systolic values > 200 mmHg and diastolic values > 105 mmHg despite treatment; malignancy; endocarditis lenta; drug abuse; pregnancy; participation in a clinical trial during the last four weeks; thromboembolic complications between start of treatment and randomisation; discontinuation of study medication due to adverse events; withdrawal of consent
Interventions	Treatment: Certoparin 3000 u anti‐Xa Control: Certoparin 3000 u anti‐Xa for 14 days then placebo  Duration: 42 days
Outcomes	Primary: Composite of symptomatic or asymptomatic DVT (proximal and/or distal), symptomatic PE and deaths related to VTE Secondary: Coagulation parameters Bleeding definition ‐ not provided
Notes	Funding: Supported by Novartis Pharma, Germany, test kits for fibrin monomers and Ddimer sponsored by Roche Diagnostics Germany, protein C resistance kits sponsored by Dada Behring Germany Method of VTE evaluation/confirmation: DVT was screened for by compression and duplex ultrasonography every week and confirmed by ascending leg and pelvic venography (whenever possible). PE was verified by pulmonary angiography, spiral CT or perfusion lung scanning
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information provided on sequence generation
Allocation concealment (selection bias)	Unclear risk	Insufficient information provided on allocation concealment
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Double‐blind, participants given placebo
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information provided on assessor blinding
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants accounted for, although treatment group was not indicated for loss‐to‐follow‐ups
Selective reporting (reporting bias)	Low risk	All defined outcomes were reported on
Other bias	Low risk	No indication of other bias