Lorentz 1991.

Methods	The efficiency of pre‐operative deposit, pre‐operative haemodilution, and intra‐ and post‐operative autotransfusion in reducing allogeneic blood transfusions was studied in this randomised trial. Method of randomisation and allocation concealment was not clear [German article].
Participants	64 patients scheduled for total hip arthroplasty were randomly divided into one of four groups: Group 1 (Pre‐operative autologous donation group): n=16 Group 2 (Pre‐operative haemodilution group): n=16 Group 3 (Autotransfusion group): n=16 Group 4 (Control group): n=15 NB: Demographic data were not reported.
Interventions	Group 1: Pre‐operative autologous donation group had their pre‐operative blood donations stored in CPDA‐1 buffer. Three units of 450mls were requested. A pre‐donation haemoglobin (Hb) concentration of 11.0g/dL was required. Surgery was carried out in the 5th week after the first donation. Group 2: Pre‐operative haemodilution group had their blood collected to a haemoglobin of 9.0g/dL after the induction of anaesthesia and initial circulatory stabilisation. Group 3: Autotransfusion group had a cell separator used for intra‐operative and post‐operative autotransfusion. Post‐operative autotransfusion of drainage blood was continued until 6 hours after the beginning of the operation. Autologous blood collected with the cell separator was re‐transfused at the end of the operation and after the autotransfusion period irrespective of the actual Hb concentration. Group 4: Control group received standard care.
Outcomes	Outcomes reported: amount of allogeneic blood transfused, number of patients transfused allogeneic blood, blood loss.
Notes	Transfusion threshold: polygeline was used for volume resuscitation. If the Hb concentration fell below 9.0g/dL in the operating room and the intensive care unit or below 10.0g/dL in the general ward, autologous or allogeneic packed red cells were transfused.
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