Methods	Randomised controlled trial
Participants	838 critically ill patients with euvolemia after initial treatment who had Hb concentrations <9.0 g/dL within 72 hours after admission to the intensive care unit were randomly assigned to 1 of 2 groups: Liberal group: n = 420; M/F = 255/165; mean (SD) age = 58.1 (18.3) years Restrictive group: n = 418; M/F = 269/149; mean (SD) age = 57.1 (18.1) years
Interventions	Liberal group were transfused RBC when the Hb concentration fell below 10.0 g/dL. The Hb concentration was maintained between 10.0 to 12.0 g/dL. Restrictive group were transfused RBC if the Hb concentration dropped below 7. 0 g/dL. The Hb concentration was maintained between 7.0 to 9.0 g/dL.
Outcomes	Outcomes reported: mortality, length of hospital stay, length of ICU stay, blood usage (units), complications, infection rates, cardiac events, pulmonary oedema, pneumonia
Notes
Risk of bias
Bias	Authors’ judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer-generated random order
Allocation concealment (selection bias)	Unclear risk	Sealed, opaque envelopes prepared by the data-coordinating centre and distributed to each participating institution where they were opened up sequentially to determine the patients treatment assignment. The envelopes were returned periodically to the co-ordinating centre for auditing
Blinding (performance bias and detection bias) All outcomes	Unclear risk	“It was not feasible to mask the assigned transfusion strategy from health care providers”
Incomplete outcome data (attrition bias) All outcomes	Low risk	Intention-to-treat analysis used
Selective reporting (reporting bias)	Low risk	-
Other bias	Low risk	-