Koopman‐van Gemert 1993a.

Study characteristics
Methods	Design: RCT, parallel two‐arm, single centre study Setting: university teaching hospital, Nijmegen, the Netherlands Recruitment: recruitment and study dates not reported Maximum follow‐up: perioperative
Participants	40 participants undergoing elective coronary artery bypass graft surgery (CABG) were randomised to one of two groups: Group 1 (Perioperative autotransfusion) (Cell salvage/intervention group): N = 20. M:F 14:3. Mean (SD) age 64 (7.0) Group 2 (Homologous transfusion only) (Control/no cell salvage group): N = 20. M:F 17:3. Mean (SD) age 62 (10.0) There were no between‐group differences at baseline with regard to demographic data and preoperative variables.
Interventions	Group 1 (Perioperative autotransfusion) (Cell salvage/intervention group): cell salvage group received perioperative autotransfusion of blood processed by means of the Cell‐Saver III‐plus system. The blood collected before going on cardiopulmonary bypass (CPB) and the remnant from the CPB machine were transferred into the cardiotomy reservoir through a 170 µm filter. Drain blood was collected during the first 6 hours postoperatively. Blood cell processing was performed by personnel in the Red Cross Blood Bank. Before transport to the blood bank, the blood was transferred into labelled sterile one‐litre bottles. After processing, the washed erythrocyte suspension was collected into labelled sterile bags and returned to the operating theatre (OT) or intensive care unit (ICU) for re‐infusion through a 40 µm blood filter. Blood was transfused up to 10 hours after the end of the operation. This allowed a maximum of 6 hours for collection, and an extra 4 hours for transport, processing, and re‐infusion to the patient. Group 2 (Homologous transfusion only) (Control/no cell salvage group): control group did not receive autotransfusion.
Outcomes	Outcomes reported: amount of blood collected by the cell saver, amount of blood re‐transfused from the cell saver, amount of allogeneic blood transfused, number of participants transfused allogeneic blood, adverse events, blood loss
Notes	Transfusion protocol: allogeneic packed cells were transfused to maintain an Hct at 30%. Prospective registration status: the study was published prior to 2010. Ethical approval: it is not clear whether the study was approved by an ethics committee or institutional review board Language of publication: English Trial funding: not reported Conflicts of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	"Alternatingly allocated to group I or II at the moment of blood processing"
Allocation concealment (selection bias)	High risk	Based on the method of randomisation, group allocation is unlikely to be concealed: "Alternatingly allocated to group I or II at the moment of blood processing"
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: "homologous packed cells were transfused to maintain their haematocrit at 0.30 l/l (if needed)."
Blinding of participants and personnel (performance bias) Subjective: all other outcomes	Low risk	No mention of blinding but clear description of how blood loss was calculated
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	No mention of blinding but clear description of how blood loss was calculated
Incomplete outcome data (attrition bias) All outcomes	Low risk	Three participants from Group 1 were excluded from the study because they did not receive their autologous blood due to logistical problems. Trialists also planned to fully disclose issues: "lf definite errors have and can be as occurred, identified such, the results are excluded from the calculations. This will be mentioned in the text and/or tables. The data remaining are then reexamined without these suspect resulls [sic]. All extreme data for which no reason can be found for exclusion are included in the final analysis."
Selective reporting (reporting bias)	Unclear risk	No trial registration or published protocol is available to compare
Other bias	Unclear risk	No baseline imbalance noted. Funding and conflicts not reported