Newman 1997.

Study characteristics
Methods	Design: RCT, parallel two‐arm, single‐centre study Setting: university teaching hospital, Bristol, Avon, UK Recruitment: recruitment and study dates not reported Maximum follow‐up: duration of hospital stay
Participants	70 consecutive participants undergoing unilateral total knee replacement were randomly allocated to one of two groups: Reinfusion group (Cell salvage/intervention group): N = 35 Homologous transfusion group (Control/no cell salvage group): N = 35 The mean age of participants enroled in study was 72 years. No further demographic data are reported.
Interventions	Reinfusion group (Cell salvage/intervention group): cell salvage group (Dideco 797 reinfusion system) had deep and superficial drains inserted before skin closure and connected to the Dideco 797 reinfusion system which maintains a constant suction of ‐25 mmHg. The drainage collected was mixed with citrate in a ratio of 12:1, filtered during collection and again during reinfusion through a 40 µm filter. No washing took place. Drainage was collected for 6 hours or until 500 mL had accumulated, at which point reinfusion of the unwashed salvaged blood took place. Homologous transfusion group (Control/no cell salvage group): control group had deep and superficial drains inserted before skin closure and connected to a standard Haemovac system which maintains a constant suction of ‐25 mmHg. Autotransfusion was not available to this group.
Outcomes	Outcomes reported: amount of blood re‐transfused from cell saver, amount of allogenic blood transfused, number of participants transfused allogeneic blood, adverse events, hospital length of stay
Notes	Transfusion protocol: use of a transfusion protocol is not reported. Prospective registration status: the study was published prior to 2010. Ethical approval: the study was approved by an ethics committee. Language of publication: English Trial funding: none declared Conflicts of interest: Sorin biomedical institutional support declared
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Method used to generate allocation sequences was adequate: using random number tables
Allocation concealment (selection bias)	Unclear risk	Method used to conceal treatment allocation was unclear
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	High risk	The study was unblinded. The criteria for diagnosing infections were not defined.
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	The study was unblinded. The criteria for diagnosing infections were not defined.
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants randomised are accounted for in the reported outcomes, ITT analysis
Selective reporting (reporting bias)	Unclear risk	No trial registration or published protocol is available to compare
Other bias	Low risk	Broadly similar at baseline. Funding declared