Shen 2016.

Study characteristics
Methods	Design: RCT, parallel two‐arm, single‐centre study Setting: regional hospital, Hangzhou, Zhejiang, China Recruitment: April 2013 to September 2014 Maximum follow‐up: duration of hospital stay
Participants	110 participants scheduled for elective cardiac surgery on CPB were randomised to one of the following two groups: Group CS (Cell Salvage/intervention group): N = 55. 2 participants were excluded from the analysis due to equipment failure (N = 1) and death (N = 1). Total number analysed was therefore N = 53. M:F 27:23. Mean (SD) age 50.42 (15.43) Group C (Control/no cell salvage group): N = 55. 5 participants were excluded from the analysis due to cell salvage use (N = 4) or death (N = 1). Total number analysed was therefore N = 50. M:F 24:26. Mean age (SD) 52.53 (15.65) There were no differences between the groups at baseline assessment.
Interventions	Group CS (Cell Salvage/intervention group): cell salvage group had shed blood from the wound and mediastina collected in the cell saver reservoir (Haemonetics, USA). A 125 mL collection bowl was used. Residual CPB circuit blood was also collected in the reservoir at completion. Collected blood was filtered, centrifuged, washed and concentrated prior to re‐transfusion. All collected and cell salvaged blood was returned to the patient prior to the end of surgery. Group C (Control/no cell salvage group): in the control group, shed blood from the wound and mediastina were aspirated and discarded. Residual CPB circuit blood was also discarded.
Outcomes	Outcomes reported: volume of intraoperative blood loss, volume of mediastinal tube drainage at 6 hours and 24 hours postoperatively, volume of perioperative blood transfusion (including volume of autologous blood), volume of allogeneic blood transfused, adverse postoperative events (excessive bleeding, re‐operation, cardiovascular failure, severe arrhythmias, myocardial infarction, infection, renal failure, respiratory failure, epileptic syndrome, cognitive decline, death)
Notes	Transfusion protocol: “Allogeneic RBC were transfused if Hb < 8 g/dL in Group C (Control group). In Group CS (Autotransfusion group), allogeneic RBC transfusion was used only if Hb was < 8 g/dL after all autologous blood was transfused.” Prospective registration status: the study was prospectively registered with a trials registry (ChiCTR‐TRC‐13003268). Ethical approval: the study was approved by the Ethics Committee of the Zhejiang Provincial People’s Hospital (Approval document ID: 2013KY035). Language of publication: English Trial funding: Natural Science Foundation of Zhejiang Province Conflicts of interest: none reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomisation list used. No further details available
Allocation concealment (selection bias)	Unclear risk	Randomisation was performed using an open randomisation schedule (randomisation list); unclear whether this meant the allocation schedule was visible in advance
Blinding of participants and personnel (performance bias) Objective outcome: mortality	Low risk	Objective outcome (mortality) unlikely to be influenced by blinding
Blinding of participants and personnel (performance bias) Subjective: transfusion protocol	Low risk	Transfusion protocol in place: allogeneic RBC were transfused if Hb < 8 g/dL in Group C (control group). In Group CS (autotransfusion group), allogeneic RBC transfusion was used only if Hb was < 8 g/dL after all autologous blood was transfused.
Blinding of participants and personnel (performance bias) Subjective: all other outcomes	High risk	No blinding of study personnel, which the authors acknowledge may have introduced bias to the study results
Blinding of outcome assessment (detection bias) Objective outcomes: mortality and transfusions	Low risk	Objective outcome (mortality) unlikely to be influenced by blinding
Blinding of outcome assessment (detection bias) Subjective outcomes	High risk	No blinding of study personnel, which the authors acknowledge may have introduced bias to the study results. Method for measuring blood loss clearly defined. Methods for measuring other outcome measures not defined.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No loss to follow‐up, all outcomes reported. CONSORT diagram
Selective reporting (reporting bias)	Low risk	A study protocol is available and reported outcomes are in line with those specified. However, an important outcome, mortality, was excluded from the study. Two participants died within 24 hours of surgery and were excluded from the analysis, though data could be extracted for these participants.
Other bias	Low risk	No baseline imbalance. Funding (non‐pharmaceutical) and conflicts (none) were reported