Bush 1997.

Methods	Randomised controlled trial
Participants	99 participants undergoing elective aortic or infrainguinal arterial reconstruction were randomized to 1 of 2 groups: Liberal group: n = 49; M/F = 41/8; mean (SD) age = 64 (11) years Restrictive group: n = 50; M/F = 32/18; mean (SD) age = 66 (10) years
Interventions	The liberal group had their Hb concentrations maintained at or above 10.0 g/dL. The restrictive group were transfused only when their Hb concentration fell below 9.0 g/dL.
Outcomes	Primary endpoints were myocardial ischaemia, myocardial infarction, and death. Secondary endpoints were length of intensive care unit stay, hospital stay, and graft patency.
Notes	‐
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	The trial reported no information regarding this domain.
Allocation concealment (selection bias)	High risk	Sealed envelopes were chosen at random for participant assignment.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Both surgeons and anaesthesiologists were informed of the group of randomisation.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	The trial reported no information regarding this domain.
Incomplete outcome data (attrition bias) All outcomes	Low risk	The outcome data appeared to be complete.
Selective reporting (reporting bias)	Low risk	No reporting bias was apparent.
Other bias	Low risk	No other biases identified.