Shehata 2012.

Study characteristics
Methods	Design: RCT, parallel 2‐arm, open‐label, single‐site pilot trial Setting: university teaching hospital, Toronto, Canada Recruitment: January 2007 to June 2010 Maximum follow‐up: 30 days
Participants	50 adult participants undergoing cardiac surgery with a CARE score (a score for cardiac surgery participants used to predict morbidity and mortality) of 3 or 4, or participants of advanced age defined as ≥ 80 years Liberal group: n = 25; mean age (SD) = 68.8 (9.2) years Restrictive group: n = 25; mean age (SD) = 67.2 (11.2) years
Interventions	Liberal group: received transfusion if Hb was ≤ 9.5 g/dL during CPB and < 10 g/dL after CPB Restrictive group: received transfusion if Hb was ≤ 7.0 g/dL during CPB and ≤ 7.5 g/dL after CPB
Outcomes	Primary outcome: enrolment rate and overall adherence to transfusion strategies (pilot study). Clinical outcomes were assessed
Notes	Trial title: Transfusion Triggers in Cardiac Surgery Trial registration (not prospective; record posted 6 months after trial start): NCT00470444 Trial funding: this trial was supported by Canadian Blood Services SPF XT00070. Canadian Blood Services as a funding agency had no role in the design and conduct of the trial COI statement by investigators: "the authors declare that they have no conflicts of interest relevant to the manuscript submitted to TRANSFUSION" (Shehata 2012 p 97)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	An independent statistician generated the allocation sequence
Allocation concealment (selection bias)	Low risk	Opaque sequential sealed envelopes were opened at the start of surgery
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' Clinicians and participants were not blinded
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	Low risk	No data from subjective outcomes (e.g. function)
Incomplete outcome data (attrition bias) All outcomes	Low risk	Outcome data appeared complete for all 50 participants
Selective reporting (reporting bias)	Low risk	This pilot trial was registered 6 months after recruitment began. All expected outcomes for a pilot were reported
Other bias	Low risk	No other biases were apparent