Jorgensen 2002.

Methods	Study design: randomized, controlled, assessor‐blinded, open, multicenter trial Method of randomization: random numbers Concealment of allocation: sealed envelopes Losses to follow‐up: 95; treatment group 49; control group 46. (discomfort with self‐injection 18, methrorrhagia 1, refused phlebography 12, not possible to perform venography 26, miscellaneous 38
Participants	Country: Denmark Number randomized: 300 (treatment group 148; control group 152) Number reported, included in analysis, presented in study publication: 205 (treatment group 99; control group 106) Age: adult patients > 18 years (range 18 to 93) Sex (male/female): treatment group 79/69; control group 93/59 Inclusion criteria: planned plaster immobilization of the lower leg for at least 3 weeks Exclusion criteria: pregnancy, allergy to heparin or contrast media, known liver or renal impairment, uncontrolled hypertension, bleeding disorders, recent GI bleeding, or inability to perform self injection
Interventions	Treatment group: LMWH 3500 IU anti‐Xa of tinzaparin (Innohep) once daily Control group: no prophylaxis
Outcomes	At cast removal, unilateral venography was performed
Notes	Dose of tinzaparin relatively low, contained both operated and non‐operated patients, previous DVT was not excluded, 205/300 were included in final assessment
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random numbers
Allocation concealment (selection bias)	Low risk	Sealed envelopes
Blinding of participants and personnel (performance bias) All outcomes	High risk	Patients were either treated with Tinzaparin, or received no treatment. A placebo was not used.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	' assessor‐blinded'; two radiologists, unaware of treatment, independently assessed the venograms
Incomplete outcome data (attrition bias) All outcomes	High risk	95 out of 300 patients were lost to follow‐up. They were evenly divided between groups (treatment group = 49, no treatment group = 46). Reasons for losses to follow‐up were discomfort with self‐injection (18), metrorrhagia (1), refusal of phlebography (12), not possible to perform venography (26), and miscellaneous (38). Reasons varied between the two groups.
Selective reporting (reporting bias)	Unclear risk	Primary and secondary outcomes were not described in methods. Therefore, it was unclear whether all assessed outcomes were reported.
Other bias	Low risk	No other bias was detected.