Horstmann 2013.

Study characteristics
Methods	Design: RCT, parallel two‐arm, single‐centre study Setting: non‐academic regional hospital, Zwolle, the Netherlands Recruitment: August 2009 to April 2011 (study dates) Maximum follow‐up: 3 months postoperatively
Participants	204 participants undergoing primary total hip replacement were randomised to one of two groups: Autologous blood transfusion (ABT) group (Cell salvage/intervention group): N = 102. Mean (SD) age 67.3 (9.3). M:F 28:74. Mean (SD) BMI 28.3 (4.1). No drainage group (Control/no cell salvage): N = 102. Mean (SD) age 67.6 (9.4). M:F 29:73. Mean (SD) BMI 27.9 (4.7). There were no between‐group differences at baseline.
Interventions	Autologous blood transfusion (ABT) group (Cell salvage/intervention group): ABT group (Cell Salvage group) used the Sangvia, autologous blood salvage machine (low vacuum, 100 to 150 mmHg; Astratech, Mölndal, Sweden) to collect blood intraoperatively and from the drainage bottle postoperatively. Blood was sequentially filtered by the device prior to re‐transfusion. Blood salvaged intraoperatively was re‐transfused within 6 hours postoperatively. Transfusion of intraoperative collected blood did not exceed 1500 mL, and of postoperative blood, did not exceed 1000 mL. The drain was removed 24 hours after surgery. No drainage group (Control/no cell salvage): the control group did not receive a drain and intraoperative blood was not salvaged.
Outcomes	Outcomes reported: homologous blood transfusion requirement, adverse events, total blood loss, volume of intraoperatively collected and re‐transfused blood, volume of re‐transfused blood collected in the drain
Notes	Transfusion protocol: allogeneic transfusions given according to Dutch guidelines. The trigger was 6.4 g/dL for American Society of Anesthesiologists (ASA) 1 patients, 8 g/dL for ASA2/3 patients, and 9.6 g/dL for ASA 4 patients and in patients who failed to increase cardiac output to compensate for dilution. Prospective Registration Status: the study was not prospectively registered with a trials registry. Ethical approval: the study was approved by the Institutional Medical Ethics Committee, Isala Clinics, Zwolle, the Netherlands. Language of publication: English Trial funding: not reported Conflicts of interest: "Benefits from a commercial party related directly or indirectly to the subject of this article were received but directed solely to a research fund, foundation, educational institution, or other non‐profit organisation with which one or more of the authors are associated."
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No randomisation methodology provided
Allocation concealment (selection bias)	Low risk	Numbered sealed opaque envelopes containing pre‐randomised cards placed in operating theatre. But unclear who was responsible for allocation.
Blinding of participants and personnel (performance bias) Objective outcome: mortality	Low risk	No objective outcomes reported (mortality unlikely to be affected by blinding if reported in future publications)
Blinding of participants and personnel (performance bias) Subjective: transfusion protocol	Low risk	Transfusion protocol in place: additional homologous blood transfusions (HBTs) were given according to the Dutch HBT guidelines. The trigger for HBT was an Hb 6.4 g/dL for American Society of Anesthesiologists (ASA) grade 1 patients, 8.0 g/dL for ASA 2/3 patients, and 9.6 g/dL for ASA 4 patients (and in patients who failed to increase their cardiac output to compensate for dilution).
Blinding of participants and personnel (performance bias) Subjective: all other outcomes	Low risk	Surgeons were blinded to group allocation until the end of surgery, at which point allocation was revealed. Blinding of participants is not described.
Blinding of outcome assessment (detection bias) Objective outcomes: mortality and transfusions	Low risk	No objective outcomes reported (mortality unlikely to be affected by blinding if reported in future publications)
Blinding of outcome assessment (detection bias) Subjective outcomes	Low risk	Postoperative care team blinded to group allocation
Incomplete outcome data (attrition bias) All outcomes	Low risk	No loss to follow‐up; all participants are accounted for in outcome data
Selective reporting (reporting bias)	Unclear risk	No trial registration or published protocol is available to compare
Other bias	Unclear risk	Conflicts of interest: "Although none of the authors has received or will receive benefits for personal or professional use from a commercial party related directly or indirectly to the subject of this article, benefits have been or will be received but will be directed solely to a research fund, foundation, educational institution, or other non‐profit organisation with which one or more of the authors are associated."