Bergqvist 2002.

Methods	RCT, double‐blinded, venography
Participants	Patients undergoing elective, open, curative surgery for malignant disease of the gastrointestinal (excluding esophagus) tract, genitourinary tract or female reproductive organs.
Interventions	LMWH (enoxaparin 40 mg, total treatment period of 25 to 31 days) or placebo.
Outcomes	LMWH 165 Placebo167
Notes	ENOXACAN II trial. Follow‐up period 3 months. Complete follow‐up. All patients were scheduled for bilateral venography. Adequate definitions of VTE and bleeding complications were described in the paper. Venography performed between 25 and 31 days.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not described in the manuscript. Randomization stratified according to the country where institution was located.
Allocation concealment (selection bias)	Unclear risk	Not described in manuscript.
Blinding (performance bias and detection bias) All outcomes	Low risk	Placebo‐controlled double‐blind study. Patients, healthcare providers, data collectors, outcome assessors, and data analysts were blinded.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not described in manuscript.
Incomplete outcome data (attrition bias) All outcomes	High risk	Eighty‐one (32.7%) patients in placebo group and 88 (34.8%) patients in experimental group excluded due to lack of adequate venography.
Selective reporting (reporting bias)	Unclear risk	Modified intention‐to‐treat analysis of patients reaching an evaluable VTE end point (venogram or objection verification of symptomatic VTE).
Other bias	Low risk	The study appears to be free of other sources of bias.