Billote 2002.

Methods	Design: Randomised controlled trial. Setting: Single centre, Northwestern Memorial Hospital, Northwestern University Medical School, Illinois, USA.
Participants	N = 112, patients undergoing elective total hip replacement (96 patients completed the trial). PAD group (I) = M/F = 26/16, age (mean+SD) = 58 (11). Control group (C) = M/F = 35/19, age (mean+SD) = 61 (14). Baseline risk factors: no significant medical co‐morbidities. Inclusion criteria: baseline Hb at least 120 g/L (finger‐prick). Exclusion criteria: severe or unstable cardiac disease; uncontrolled hypertension; symptomatic carotid or vertebral artery stenosis; a bleeding diathesis or bacteraemia.
Interventions	PAD group (n = 42) Control group (n = 54) Timing of autologous blood collection/retransfusion: whole blood donated once a week with last unit no later than 2 weeks prior to surgery, retransfused post‐operatively (1 patient had retransfusion intra‐operatively) (PAD group only) Volume of autologous blood collected/retransfused: 2 units, maximum 1 unit (approximately 500 g) at each time; 2 patients in PAD group only pre‐donated 1 unit each. Iron supplementation: Ferrous sulfate tablets (325 mg twice daily) were prescribed to all patients. PAD group started supplementation after their first autologous blood donation, control group started it 10 days before surgery. Use of transfusion threshold: need for intra‐operative blood transfusion decided by Anaesthetist (not a co‐investigator in the study) and identical thresholds for autologous and allogeneic, autologous blood transfused before allogeneic if available; standardised protocol indicated need for red blood cell transfusion when: acute blood loss of more than 25% estimated blood volume with or without hypovolaemic shock; tachycardia attributed to haemoglobin‐responsive hypoxia and unresponsive to intravenous fluid administration; haemoglobin concentration less than 70 g/L in healthy patients regardless of age; haemoglobin concentration of less than 80 g/L in patients with co‐morbid diseases such as cerebrovascular accident, heart disease, peripheral vascular disease or chronic obstructive pulmonary disease. Postoperative decision to transfuse made by orthopaedic surgeon (one of which was an author of the study), indication for autologous transfusion included haemoglobin level of less than 100 g/L in postoperative period. Other active interventions given to both arms: all patients received thromboprophylaxis on first postoperative day continued for one month. Length of surgery: no details.
Outcomes	Outcomes reported: number of patients transfused with allogeneic blood, number of patients transfused with autologous blood, volume of autologous blood transfused (no SD), pre‐operative Hb, blood loss (mLs), autologous blood wastage (no SD), length of hospital stay (no SD).
Notes	Period of study: not stated Length of study: 6 weeks A priori sample size: Yes Baseline comparability: No significant difference between the two groups in regard to age, gender, BMI, blood volume or baseline medical condition.
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Low risk	Computer‐generated randomisation scheme (Analysis Tool Pack, Microsoft Excel).
Allocation concealment?	Low risk	Sequential sealed envelope by an independent research nurse.
Blinding? All outcomes	Unclear risk	Participant blinding: unclear. Assessor blinding: unclear.
Intention‐to‐treat analysis?	High risk	Data were not analysed on an intention‐to‐treat basis.