Westerberg 2004.

Study characteristics
Methods	Design: RCT, parallel two‐arm, single‐centre study Setting: university teaching hospital, Gothenburg, Sweden Recruitment: recruitment and study dates not reported Maximum follow‐up: 12 hours postoperatively
Participants	35 participants undergoing cardiac surgery were randomly allocated to one of two groups: Retransfusion group (cell salvage/intervention group): N = 12. M:F 9:3. Mean (SD) age 64 (7.0) No retransfusion group (control/no cell salvage group): N = 17. M:F 16:1. Mean (SD) age 67 (8.3) There was imbalance between groups in aortic cross‐clamp time and CPB time. All other demographic and baseline data were comparable between groups. NB: 6 participants were excluded from the final analysis.
Interventions	Retransfusion group (cell salvage/intervention group): autotransfusion group had their cardiotomy suction blood during cardiopulmonary bypass (CPB) and mediastinal shed blood during the first 12 hours postoperatively re‐transfused. No retransfusion group (control/no cell salvage group): control group had their cardiotomy suction blood and mediastinal shed blood discarded. NB: all participants received intravenous tranexamic acid (TXA) 2 g before surgery and 2 g after skin closure.
Outcomes	Outcomes reported: number of participants transfused allogeneic blood, volume of shed mediastinal blood, blood loss
Notes	Transfusion protocol: the use of a transfusion protocol was not reported. Prospective registration status: the study was published prior to 2010. Ethical approval: the study protocol was approved by the Research Ethics Committee of the Medical Faculty, University of Gothenburg. Language of publication: English Trial funding: Gothenburg Medical Association Conflicts of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method used to generate allocation sequences was not described.
Allocation concealment (selection bias)	Unclear risk	Method used to conceal treatment allocation was not described.
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	High risk	No transfusion protocol in place
Blinding of participants and personnel (performance bias) Subjective: all other outcomes	Unclear risk	The blinding status of participants and personnel was 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	Unclear risk	The blinding status of outcome assessors was not described.
Incomplete outcome data (attrition bias) All outcomes	High risk	35 randomised, 29 analysed ‐ 6 excluded but seems wrong to exclude them. Nearly 20% excluded; appears to be imbalanced (more excluded from re‐transfusion group)
Selective reporting (reporting bias)	Unclear risk	No trial registration or published protocol is available to compare
Other bias	Unclear risk	Minor baseline imbalance, likely due to unbalanced exclusions (did it impact males in the retransfusion group only). Funding reported (non‐pharmaceutical)