de Almeida 2015.

Methods	Randomised clinical trial
Participants	Adult participants who underwent a major surgical procedure for abdominal cancer and required postoperative care in the ICU Liberal: n = 97; mean age (SD) = 64 (14) years Restrictive: n = 101; mean age (SD) = 64 (12) years
Interventions	While in the ICU, the liberal transfusion group received transfusion when Hg < 9 g/dL, and the restrictive transfusion group received transfusion when Hg < 7 g/dL.
Outcomes	The primary outcome was a composite of all‐cause mortality or severe clinical complications within 30 days. Severe clinical complications included major cardiovascular complications, septic shock, acute kidney injury requiring renal replacement therapy, ARDS, and reoperation.
Notes	‐
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The chief statistician ensured random sequence generation.
Allocation concealment (selection bias)	Low risk	The trial used opaque envelopes that were opened sequentially.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Clinicians or participants were not blinded.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	The participants and the study investigators who classified outcomes and those who conducted the follow‐up telephone assessments were blinded to the study‐group assignments and had no access to transfusion data.
Incomplete outcome data (attrition bias) All outcomes	Low risk	No attrition bias was apparent.
Selective reporting (reporting bias)	Low risk	No reporting bias was apparent.
Other bias	Low risk	No other biases identified.