Tay 2020.

Study characteristics
Methods	Design: RCT, parallel 2‐arm, multicentre, non‐inferiority trial Setting: 4 HCT centres, Canada Recruitment: March 2011 to February 2016 Maximum follow‐up: 100 days
Participants	300 participants over 18 years of age undergoing autologous or allogeneic HCT for any haematological malignancy randomised There was one late exclusion  Liberal group: n = 150;  M/F = 94/56; age = 56.0 (IQR 48.3 to 62.2) Restrictive group: n = 149; M/F = 97/52; age = 57.5 (IQR 48.9 to 62.7)
Interventions	Liberal group: received 2 units of RBCs if Hb fell to < 9.0 g/dL (targeted to maintaining a level of 9.0 g/dL to 11.0 g/dL) Restrictive group: received 2 units of RBCs if Hb fell to < 7.0 g/dL (targeted to maintaining a level of 7.0 g/dL to 9.0 g/dL)
Outcomes	Primary outcome: health‐related quality of life (HRQOL) measured by FACT‐BMT score at day 100
Notes	Trial registration (prospective): NCT01237639 Trial funding: supported by grants from the Canadian Institute of Health Research and the Canadian Blood Services COI statement by investigators: "Jason Tay: Honoraria: Celgene, Takeda, Sanofi Canada, Amgen. David S. Allan: Other Relationship: Canadian Blood Services. Mohamed Elemary: Consulting or Advisory Role: Jazz Pharmaceuticals, Amgen, Roche Canada. Adrienne Fulford: Honoraria: Teva Pharmaceutical Industries; Consulting or Advisory Role: Amgen. Irwin Walker: Honoraria: Jazz Pharmaceuticals; Consulting or Advisory Role: Jazz Pharmaceuticals; Research Funding: Sanofi Canada;Travel, Accommodations, Expenses: Jazz Pharmaceuticals. Anargyros Xenocostas: Honoraria: Novartis (Inst), Amgen (Inst), Apobiologix (Inst), Pfizer (Inst); Research Funding: Novartis (Inst)" (Tay 2020 p 1474) No other potential conflicts of interest were reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated randomisation sequence
Allocation concealment (selection bias)	Low risk	Secure online electronic randomisation platform was used
Blinding of participants and personnel (performance bias) Objective outcomes	Low risk	Blinding of personnel for this intervention is not feasible, but in our view, for objective outcomes such as mortality (the primary outcome used within this review), we graded risk of bias as 'low' Not possible to blind patients or caregivers
Blinding of outcome assessment (detection bias) Objective measures	Low risk	Blinding of mortality (the primary outcome used within this review) is not relevant, and we graded risk of bias as 'low'
Blinding of outcome assessment (detection bias) Subjective measures	High risk	Health‐related outcomes were self‐reported and were trial primary outcomes. Patients were not blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	300 participants were randomised. There was 1 late exclusion in the restrictive group and 2 in each group were lost to full follow‐up. 299 participants were included from ITT analysis
Selective reporting (reporting bias)	Low risk	Trial was prospectively registered (NCT01237639). All outcomes appear to be reported
Other bias	Low risk	None was evident. A small difference in storage age at transfusion between the 2 arms was noted. Overall transfusion adherence rate was 95%