Šarkanoviü 2013.

Study characteristics
Methods	Design: RCT, parallel two‐arm, single‐centre study Setting: regional hospital, Novi Sad, Serbia Recruitment: during 2010. Specific recruitment and study dates not reported. Maximum follow‐up: not reported
Participants	112 participants undergoing total knee replacement (TKR) were randomised to one of two groups: Group 1 (Allogeneic blood) (Control/no cell salvage group): N = 55. Mean age 65.24. M:F: 14:41 Group 2 (Autologous blood) (Cell saver/intervention group): N = 57. Mean age 67.2. M:F 12:45 There were minor differences in baseline characteristics between the groups.
Interventions	Group 1 (Allogeneic blood) (Control/no cell salvage group): cell salvage group received postoperative cell salvage and autotransfusion once drainage volume reached 200 mL. Intraoperative cell salvage was also used (Haemonetics 5+, USA) to scavenge blood from the operative field and reinfuse after processing. Group 2 (Autologous blood) (Cell saver/intervention group): allogeneic transfusion group (control group) received standard perioperative care and allogeneic blood transfusions when required.
Outcomes	Outcomes reported: blood loss, time to sitting, time to standing, time to walking, length of hospital stay, number of participants receiving allogeneic blood transfusion, venous thromboembolism (VTE) rate, perioperative infection, wound complications, major cardiovascular morbidity ‐ MACE definition not specified
Notes	Transfusion protocol: the transfusion trigger for the group that received allogeneic blood was 85 g/L. Prospective registration status: no information is available to determine whether the study was prospectively registered with a trials registry. We attempted to contact the authors to request this information but received no response. Ethical approval: no information is available to determine whether the study received ethical approval. We attempted to contact the authors to request this information but received no response. Language of publication: English and Serbian Trial funding: not reported Conflicts of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No mention of randomisation process
Allocation concealment (selection bias)	Unclear risk	Allocation concealment is not described and so a judgment cannot be made
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: “The transfusion trigger for the group that received allogeneic blood was 85 g/L.”
Blinding of participants and personnel (performance bias) Subjective: all other outcomes	High risk	Subjective outcome measures not defined or, where definitions provided, vague with significant scope for between‐participant variability
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	High risk	Subjective outcome measures not defined or, where definitions provided, vague with significant scope for between‐participant variability
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No mention of individuals identified who did not meet criteria or loss to follow‐up
Selective reporting (reporting bias)	Unclear risk	No trial registration or published protocol is available to compare
Other bias	Unclear risk	Minor differences in baseline characteristics. No mention of conflicts or funding

ABT: autologous blood transfusion; ACD‐A: anticoagulant citrate dextrose solution; AE: adverse event; ASA: American Society of Anesthesiologists; BMI: body mass index; CABG: coronary artery bypass graft; CPB: cardiopulmonary bypass; DVT: deep vein thrombosis; F: female; FFP: fresh frozen plasma; Hb: haemoglobin; Hct: haematocrit; ICU: intensive care unit; IQR: interquartile range; ITT: intention‐to‐treat; LOS: length of stay; M: male; MACE: major adverse cardiac events; NHS: National Health Service; NSAID: non‐steroidal anti‐inflammatory drug; PE: pulmonary embolism; PJI: prosthetic joint infection; RBC: red blood cell; SBP: systolic blood pressure; SD: standard deviation; THA/THR: total hip arthroplasty/total hip replacement; TKA/TKR: total knee arthroplasty/total knee replacement