Menges 1992.

Methods	The influence of two different methods of autologous transfusion were investigated in a prospective randomised controlled trial. Method of randomisation and allocation concealment was not described [German article].
Participants	42 patients undergoing total hip surgery and pre‐operative plasmapheresis (Abbott Autotrans) were randomised to one of three groups: Group 1 (Autotransfusion group): n=14; mean (sd) age = 55.9 (18.2) years Group 2 (Autotransfusion + FFP group): n=16; mean (sd) age = 70.6 (7.0) years Group 3 (Control group): n=12; mean (sd) age = 66.7 (12.7) years.]
Interventions	Group 1: Autotransfusion group for the substitution of blood loss, received in addition to crystalloids and colloids, only autologous packed red blood cells (erythrocyte concentrate) collected by the Autotrans BT 795 P, Dideco system. Group 2: Autotransfusion + FFP group received additionally, intra‐operative and post‐operative autologous fresh frozen plasma (FFP). Group 3: Control group for the substitution of blood loss, received in addition to crystalloids and colloids, only allogeneic red blood cells (erythrocyte concentrate). Autotransfusion was not used. NB: Study investigated the influence of two different methods of autotransfusion on the intravascular haemostatic system.
Outcomes	Outcomes reported: amount of blood re‐transfused from the cell saver, number of patients transfused allogeneic blood, blood loss, Hb & Hct levels, clotting status (PT/TT/PTT/ATIII).
Notes	Transfusion threshold: patients were transfused if haemoglobin fell below 9.0g/dL or haematocrit fell below 28%.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method used to generate allocation sequences was unclear.
Allocation concealment (selection bias)	Unclear risk	Method used to conceal treatment allocation was unclear.
Blinding (performance bias and detection bias) All outcomes	High risk