Teetzman 2014.

Study characteristics
Methods	Design: RCT, parallel two‐group, single‐centre study Setting: regional hospital in Norway Recruitment: December 2009 to December 2012 (study dates) Maximum follow‐up: duration of hospital stay
Participants	164 participants undergoing elective hip surgery were randomised to one of two treatment groups: Group 1 (Autotransfusion of autologous blood) (cell salvage/intervention group): N = 74. Mean age 73 Group 2 (Allo‐transfusion group) (control/no cell salvage group): N = 90. 87 participants were included in the final analysis after one perioperative death and erroneous administration of autologous blood to two participants. Mean age of the included 87 participants was 73. The authors state that there were no significant differences in baseline characteristics, though the percentages show differences in multiple domains (gender, medication for blood pressure, medications affecting platelets).
Interventions	Group 1 (Autotransfusion of autologous blood) (cell salvage/intervention group): participants in the autologous transfusion group underwent cell salvage using the Sangvia Blood Salvage System. Blood was collected intra‐ and postoperatively. The maximum collection time was 6 hours and maximum collection volume was 1500 mL. Autologous transfusion was routinely given to participants in this group unless there was a failure in the collection process or the sample was insufficient (< 200 mL). The salvaged blood was not washed prior to reinfusion. Group 2 (Allo‐transfusion group) (control/no cell salvage group): the control group received standard perioperative care and allogeneic blood transfusions, as required, according to the clinical judgement of the doctor on duty.
Outcomes	Primary outcome: difference in infection rates between groups Secondary outcomes: volume of blood transfused, transfusion reactions, length of hospital stay, number of days on antibiotic treatment, days with body temperature > 38C
Notes	Transfusion protocol: allogeneic transfusions were prescribed by the doctor on duty according to clinical judgement. Prospective registration status: the study was retrospectively registered with a trials registry (NCT01725724). The study start date was 3 years before registration. Ethical approval: the study was approved by the regional ethics committee for Stord Hospital, Helse Fonna HF, Norway. 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)	Unclear risk	The randomisation method is not described
Allocation concealment (selection bias)	Unclear risk	The method of allocation concealment is not described
Blinding of participants and personnel (performance bias) Objective outcome: mortality	Low risk	Objective outcome (mortality) unlikely to be influenced by blinding
Blinding of participants and personnel (performance bias) Subjective: transfusion protocol	High risk	No transfusion protocol: all allogeneic transfusions were prescribed by the doctor on duty according to a clinical judgement.
Blinding of participants and personnel (performance bias) Subjective: all other outcomes	High risk	No blinding of personnel, and multiple outcomes have no clearly defined decision‐making/diagnostic criteria
Blinding of outcome assessment (detection bias) Objective outcomes: mortality and transfusions	Low risk	Objective outcome (mortality) unlikely to be influenced by blinding
Blinding of outcome assessment (detection bias) Subjective outcomes	Low risk	No blinding of outcome assessors, but infection outcome has clearly‐defined criteria that minimises risk of bias
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Low number of dropouts, but all in the control group: 3 participants were excluded from the control group following randomisation: 1 secondary to perioperative mortality and 2 due to erroneous administration of autologous blood. Imbalance in group size, no info on participant flow, so it is unclear why this is the case (whether more participant were excluded or crossed over)
Selective reporting (reporting bias)	Unclear risk	No trial registration or published protocol is available to compare
Other bias	Unclear risk	Funding and conflicts not reported. Authors state no significant difference in baseline characteristics, though the percentages show differences in multiple domains (gender, medication for blood pressure, medications affecting platelets).