Altinel 2007.

Study characteristics
Methods	Design: RCT, parallel two‐arm, single‐centre study Setting: university teaching hospital, Afyon, Turkey Recruitment: recruitment and study dates not reported Maximum follow‐up: duration of hospital stay
Participants	32 participants undergoing total knee arthroplasty were randomised to one of two groups: Study group (Cell salvage/intervention group): N = 16. M:F 0:16. Mean (SD) age 66.9 (9.1). Mean (SD) BMI 32.6 (4.3) kg/m2. Control group (Control/no cell salvage group): N = 16. M:F 2:14. Mean (SD) age 66.2 (7.1). Mean (SD) BMI 34.3 (8.3) kg/m2. There was no baseline imbalance between groups with regard to demographic data.
Interventions	Study group (Cell salvage/intervention group): cell salvage group (ConstaVac CBCII autotransfusion system) had wound drain connected at the end of the operation. The drain fluid was collected during the first 6 hours. Collected blood was transfused at the end of the 6th hour. Reinfusion was performed using a standard 40 µm blood filter between the collection bag and the intravenous site. After the 6 hours, any blood collected from the reinfusion drain was discarded. Control group: control group received standard care without autotransfusion.
Outcomes	Outcomes reported: number of participants transfused allogeneic blood, blood loss, hospital length of stay, adverse events
Notes	Transfusion protocol: allogeneic blood transfusion was given if the haemoglobin level was < 9.0 g/dL. Prospective registration status: the study was published prior to 2010. Ethical approval: the study was approved by the Ethics Committee of the Faculty of Medicine, Afyon Kocatepe, Turkey. 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)	Low risk	Lots drawn
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	Low risk	Transfusion protocol in place: if the blood haemoglobin level was below 9 g/dL and there were evident clinical signs of anaemia, patients were given additional homologous blood.
Blinding of participants and personnel (performance bias) Subjective: all other outcomes	Unclear risk	Blinding status of participants and personnel 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	Unclear risk	One outcome (chest x‐ray evaluation) noted as blinded assessment; suggests the remaining outcomes were not blinded, but not clear
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Unclear patient flow ‐ baseline characteristics suggest 16 per group, but whether this is number randomised, or if all were analysed, is not clear
Selective reporting (reporting bias)	Unclear risk	No trial registration or published protocol is available to compare
Other bias	Unclear risk	No mention of funding or conflicts