Kock 1995.

Methods	Study design: randomized, controlled, open trial Method of randomization: randomization list stratified for varicose veins and obesity Concealment of allocation: not reported Losses to follow‐up: 5 refused to take part, 32 excluded due to exclusion criteria, data not evaluated from 52: treatment group 21; control group 31
Participants	Country: Germany Number randomized: 428; 5 refused to take part, 32 excluded due to exclusion criteria, data not evaluated from 52: treatment group 21; control group 31 (no final examination (12 treatment; 16 control), surgery performed before final examination (6 treatment, 12 control), changed groups (3 treatment, 3 control)) Number reported, included in analysis, presented in study publication: 339 (treatment group 176; control group 163) Age mean (range): treatment group 34.1 years (18 to 63); control group 33.5 years (18 to 64) Sex (male/female): treatment group 104/72; control group 104/59 Inclusion criteria: age 18 to 65, conservative treatment of injury with below‐knee cast or cylinder cast Exclusion criteria: previous DVT, pregnancy, clotting disorders or anticoagulation medication, bleeding, chronic venous insufficiency, contraindications for heparin prophylaxis, plaster cast after surgery
Interventions	Treatment group: LMWH 32 mg (certoparin; Mono‐Embolex NM) once daily Control group: no prophylaxis
Outcomes	At randomization and at plaster removal, compression ultrasound and duplex scanning were performed; suspected positive findings were confirmed by phlebography.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomization with lists stratified for varicose veins and obesity
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	High risk	Open study format, in which no placebo was used. The treatment group received injections of LMWH, the control group received none. Blinding of personnel was not described.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data of 52 out of 428 randomized participants could not be evaluated, reasons provided
Selective reporting (reporting bias)	Unclear risk	Primary and secondary outcomes were not described. Therefore, it was unclear whether all assessed outcomes were reported.
Other bias	Low risk	No other bias was detected.