Lorentz 1991.

Methods	Design: Randomised controlled trial. Setting: Germany.
Participants	N = 64 patients scheduled for total hip arthroplasty (included 63 patients in analysis). PAD group = n = 16; M/F = 8/8; mean age ± SD = 57.5 ± 9.2 years *Preoperative haemodilution group = n = 16; M/F = 6/10; mean age ± SD = 60.6 ± 8.7 years *Intra and postoperative autotransfusion group = n = 16; M/F = 9/7; mean age ± SD = 63.4 ± 7.9 years Control group = n = 15; M/F = 5/10; mean age ± SD = 63.0 ± 11.7 years [* not included in review's analyses]
Interventions	PAD group (n = 16) Control group (n = 15) Timing of autologous blood collection/retransfusion: Preoperative autologous donations were stored in CPDA‐1 buffer. A predonation Hb concentration of 11 g/dL was required. Surgery was carried out in the 5th week after the first donation. Volume of autologous blood collected/retransfused: Three units of 450 mL. Iron supplementation: Not mentioned. Use of transfusion threshold: If the Hb concentration fell below 9.0 g/dL in the operating room and intensive care unit or below 10.0 g/dL in the general ward, autologous blood or allogeneic packed red cells were transfused.
Outcomes	Outcomes reported: Number of patients exposed to allogeneic blood (n), allogeneic blood transfused (units), blood loss (mL).
Notes	Period of study: Not reported. Length of study: Not reported. A priori sample size: Not reported. Baseline comparability: Reported that the general data for the patients were comparable for both groups.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	No information.
Allocation concealment?	Unclear risk	No information.
Blinding? All outcomes	Unclear risk	No information.
Intention‐to‐treat analysis?	High risk	Data were not analysed on an intention‐to‐treat basis.

CS = Cell salvage; EPO = Erythropoietin; EVF = Erythrocyte volume fraction; Hb = Haemoglobin; PAD = Pre‐operative autologous donation.