Gannon 1991.

Study characteristics
Methods	Design: RCT, parallel two‐arm, multicentre study Setting: two university teaching hospitals, Columbus, OH, USA Recruitment: January 1989 to April 1989 Maximum follow‐up: 48 hours postoperatively
Participants	239 consecutive participants undergoing total knee replacement procedures were randomly assigned to one of two groups: Study group (Cell salvage/intervention group): N = 124. M:F 59:65. Mean age 65 Control group: N = 115. M:F 46:69. Mean age 69 The study does not comment on whether any between‐group differences were presented at baseline.
Interventions	Study group (Cell salvage/intervention group): the cell salvage group (Solcotrans autotransfusion system) had their wounds drained into postoperative blood salvage canisters. There was a 6‐hour total time limit for collection and reinfusion of blood. Because 40 mL of citrate ACD‐A was entered in each Solcotrans canister prior to use, a minimum of 320 mL of blood and citrate volume was necessary before reinfusion to prevent citrate toxicity. If wound drainage was slow and an adequate volume had not been collected before the 6‐hour time limit, the canister and blood were discarded, and a standard collection canister was attached to the drainage tube for the duration. If wound drainage was rapid, the canister was allowed to fill completely (500 mL volume). The blood was then infused at an appropriate rate as long as the 6‐hour pre‐canister limit was not exceeded. Another Solcotrans canister could then be attached, beginning a new 6‐hour time interval. Intraoperative blood salvage was not used. Control group: the control group had their wounds drained into standard 400 mL suction canisters. Autotransfusion was not performed.
Outcomes	Outcomes reported: amount of blood re‐transfused from the cell saver, number of participants transfused allogeneic blood, adverse events
Notes	Transfusion protocol: all participants whose postoperative haemoglobin value was < 9.0 g/dL were transfused allogeneic blood. The decision to transfuse patients with haemoglobin values > 9.0 g/dL was made by the internist on the basis of each patient's medical condition. 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)	Low risk	A computer‐generated random number list was used pre‐operatively to assign participants to either intervention or control.
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	Low risk	Transfusion protocol: all patients whose postoperative haemoglobin value was < 9.0 g/dL were transfused allogeneic blood. The decision to transfuse patients with haemoglobin values > 9.0 g/dL was made by the internist on the basis of each patient's medical condition
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 participants and personnel was not described.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No information on participant flow. The total number of participants contributing to the outcome measures is not reported
Selective reporting (reporting bias)	Unclear risk	No trial registration or published protocol is available to compare
Other bias	Unclear risk	No baseline characteristics provided per group. Funding and conflicts not reported