L‐8541.

Methods	Multi‐centre, randomised, single‐blind, parallel‐group control study
Participants	Total number of participants: 237 Number of participants allocated to each group: fondaparinux (FX) group: 119, enoxaparin (EN) group: 118 Number of participants excluded and/or lost to follow‐up: FX group: 6 (5 adverse events, 0 lack of efficacy, 1 other reasons), EN group: 3 (2 adverse events, 0 lack of efficacy, 1 other reasons) Inclusion: Male/female patients (aged 18 to 75 years) who were to undergo an elective hip or knee replacement or revision, and who gave written informed consent, were included in the study. Exclusion: Exclusion criteria included the following: history of serious active bleeding in past 3 months; concurrent or history of thrombocytopenia (platelet count < 100 x 109/L); concurrent haemorrhagic cerebrovascular disease or surgical history in brain, spine or eye; abnormality in hepatic (> 1.5 x ULN), renal (CrCl < 30 mL/min) or cardiac function, uncontrolled hypertension or tumour; and concurrent need for hip and knee replacement or double hip or knee replacement.
Interventions	FX: 2.5 mg for 7 ± 2 days (once daily sc injection) EN: 40 mg for 7 ± 2 days First treatment injection (placebo or enoxaparin) was administered at 12 ± 2 hours before surgery, then was continued for 7 ± 2 days post surgery, via daily sc injection.
Outcomes	Primary efficacy outcome: overall DVT events as confirmed by colour ultrasound imaging conducted within 2 days after the last dose following orthopaedic surgery Primary safety outcome: major bleeding recorded between day 1 and day 9 post surgery
Notes	Use of adjunctive anticoagulative methods: no mention of use of any adjunctive anticoagulative method Used for sensitivity analysis
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Multi‐centre, randomised, single‐blind, parallel control study" Comment: probably done, as earlier reports from the same company clearly describe use of random sequences
Allocation concealment (selection bias)	Low risk	Quote: "Multi‐centre, randomised, single‐ blind, parallel control study" Comment: probably done, as most earlier multi‐centre RCT reports clearly mentioned that studies of the same medicine organised by the same company were centrally randomised
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "Multi‐centre, randomised, single‐blind, parallel control study" Comment: probably not done
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not clearly described Comment: unclear
Incomplete outcome data (attrition bias) All outcomes	Low risk	94.96% and 97.46% of participants in both groups completed the study. Comment: probably done
Selective reporting (reporting bias)	Low risk	All primary efficacy and safety outcomes listed in the Methods section were reported. Comment: low risk of bias
Other bias	Unclear risk	Company sponsored