Methods	This study was prospectively performed on the cases of a single vascular surgeon operating at two institutions from January 1989 to January 1990. Patients undergoing elective infrarenal abdominal aortic bypass for either occlusive or aneurysmal disease were included in the study sample. Patients were randomised on an alternating basis to either intervention or control. Method of randomisation was not described
Participants	36 patients undergoing aortobifemoral or aortobi-iliac bypass for occlusive disease were randomised to one of two groups: Group 1 (Autotransfusion group): n=18 Group 2 (Control group): n=18 NB: Demographic data were not reported.
Interventions	Group 1: Autotransfusion group (Haemonetics Cell Saver) was monitored and operated by a technician-member of the perfusion team. The Haemonetics Cell Saver delivers washed red blood cells at an average haematocrit level of 55% to 60%. Group 2: Control group did not receive autotransfusion.
Outcomes	Outcomes reported: amount of blood re-transfused from the cell saver, amount of allogeneic blood transfused, adverse events, hospital length of stay, blood loss, haemoglobin levels
Notes	Transfusion threshold: after the operation allogeneic red cell transfusions were not given to patients who were haemodynamically stable, and had haemoglobin values greater than 8.0g/dL
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method used to generate allocation sequences was not described
Allocation concealment (selection bias)	High risk	Method used to conceal treatment allocation was inadequate.
Blinding (performance bias and detection bias) All outcomes	High risk