Shirvani 1991.

Methods	Randomised controlled trial was conducted to evaluate the advantages and disadvantages of post‐operative autotranfusion in patients undergoing first‐time coronary artery bypass grafting (CABG). Method of randomisation and allocation concealment were not described.
Participants	40 patient undergoing first‐time coronary artery bypass graft sugery were randomly divided into one of two groups. The two groups were further subdivided according to whether the patients received aspirin preoperatively or not: Group 1 (Autotransfusion group ‐ aspirin): n=10 Group 2 (Autotransfusion group ‐ no aspirin): n=11 Group 3 (Control group ‐ aspirin): n=12 Group 4 (Control group ‐ no aspirin): n=9 NB: Demographic data were not reported.
Interventions	Group 1: Autotransfusion group (aspirin) patients were autotransfused using an IMED 960 Volumetric Infusion Pump but donor blood was also available if needed. Patients from this group received 75mg of aspirin daily pre‐operatively. Group 2: Autotransfusion group (no aspirin) patients were autotransfused using an IMED 960 Volumetric Infusion Pump but donor blood was also available if needed. Patients from this group did not receive 75mg of aspirin daily pre‐operatively. Group 3: Control group (aspirin) patients were transfused post‐operatively with allogeneic blood. Patients from this group received 75mg of aspirin daily pre‐operatively. Autotransfusion was not used. Group 4: Control group (no aspirin) patients were transfused post‐operatively with allogeneic blood. Patients from this group did not receive 75mg of aspirin daily pre‐operatively. Autotransfusion was not used.
Outcomes	Outcomes reported: amount of allogeneic blood transfused, number of patients transfused allogeneic blood, adverse events, re‐operation for bleeding, blood loss.
Notes	Transfusion threshold: the indication for allogeneic blood transfusion was the maintenance of a haematocrit (Hct) level of 30% to 35%.
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)	Unclear risk	Method used to conceal treatment allocation was unclear.
Blinding (performance bias and detection bias) All outcomes	High risk