Koopman 1996.
Methods | Study design: randomised controlled trial. Method of randomisation: stratified according to centre. Concealment of allocation: not blinded for treatment allocation, blinded for outcome assessment. Exclusions post‐randomisation: none. Lost to follow‐up: none. |
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Participants | Country: Netherlands, France, Italy, Australia, New Zealand. Setting: hospital. No.: 400 outpatients. Age: Mean 61 years. Sex: 203 males. Inclusion criteria: acute symptomatic proximal DVT documented by venography and/or ultrasonography. Exclusion criteria: VTE in last 2 years; suspected PE; previous treatment with heparin > 24 hours; life expectancy < 6 months; post‐thrombotic syndrome; geographic inaccessibility. |
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Interventions | Treatment: LMWH (Nadroparin‐Ca, Fraxiparine) in body weight‐adjusted fixed dose, s.c., twice daily. If appropriate, at home. Control: UFH: APTT‐adjusted dose, continuous i.v. infusion in hospital after initial i.v. bolus of 5000 Units. Treatment duration: at least 5 days; treatment cessation if INR was 2.0 or above in 2 measurements 24 hours apart. Oral anticoagulation: started on first day and continued for 3 months unless persistence of risk factors required its continuation beyond that period. INR 2.0 to 3.0. |
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Outcomes | Primary: symptomatic recurrent VTE (DVT or PE) during initial treatment, after 3 months' follow‐up and at the end of follow‐up (6 months); major haemorrhage during initial treatment and after 3 months of follow‐up. Secondary: minor haemorrhage or death during initial treatment, after 3 months of follow‐up and at the end of follow‐up (6 months); other potential outcome events; quality of life. |
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Notes | Follow‐up: 6 months. | |
Risk of bias | ||
Bias | Authors' judgement | Support for judgement |
Random sequence generation (selection bias) | Low risk | Randomisation and allocation was achieved by means of a central 24‐hour telephone service. |
Allocation concealment (selection bias) | Low risk | Randomisation and allocation was achieved by means of a central 24‐hour telephone service. |
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 | Documentation of all potential outcome events was submitted to an independent adjudication committee whose members were unaware of the treatment assignments. |
Incomplete outcome data (attrition bias) All outcomes | Low risk | Missing outcome data balanced in numbers across intervention groups. |
Selective reporting (reporting bias) | Low risk | Published report includes all expected outcomes. |
Other bias | Low risk | Study appears to be free of other sources of bias. |