Beghi 1993.

Methods	RCT
Participants	Patients (n = 39) undergoing open cardiac surgery, 20 were randomised to the LMWH group and 19 to the calcium‐heparin group. Mean age was 60.2 (± 1.9) years in LMWH and 60.5 (± 2.4) years in calcium‐heparin; 31/39 (79%) were males. One or more risk factors for DVT were reported in 100% of LMWH and 72% of calcium‐heparin patients. Indication for surgery: myocardial revascularisation (92.3%), atrial myxoma (2.6%), atrial septal defect (5.1%)
Interventions	‐ LMWH, parnaparin (3200 IU od subcutaneous) ‐ Calcium‐heparin (5000 IU tid subcutaneous) Thromboprophylaxis was started on the first day after surgery and continued for 4 postoperative days
Outcomes	Symptomatic and asymptomatic DVT. Physical examination and colour Doppler ultrasonography were used to diagnose DVT
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of random sequence generation not reported
Allocation concealment (selection bias)	Unclear risk	Method of allocation concealment not reported
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not reported if participants and personnel were blinded to study treatment
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported if outcome assessment was blinded
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	It is unclear if all participants enrolled were subsequently considered in the analysis
Selective reporting (reporting bias)	Low risk	Study not registered. No published protocol. All outcomes mentioned in the methods section were addressed in the results section
Other bias	Unclear risk	Participant characteristics are not reported. Unclear if participants were consecutively included