| Methods |
Randomised controlled trial |
| Participants |
428 consecutive participants undergoing elective primary coronary artery bypass graft surgery were randomly assigned to 1 of 2 groups:
|
| Interventions |
The liberal group received transfusions on the instructions of their individual physicians, who considered the clinical assessment of the participant and the institutional guidelines, which proposed a Hb level < 9.0 g/dL as the postoperative threshold for RBC transfusion. The restrictive group received a RBC transfusion in the postoperative period at a Hb level < 8.0 g/dL. |
| Outcomes |
Mortality, length of hospital stay, blood usage (units), blood loss, complications, infection rates, cardiac events |
| Notes |
‐ |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
High risk |
Participants were randomly assigned on the basis of the last digit of their medical record number. |
| Allocation concealment (selection bias) |
High risk |
There was inadequate concealment (record number). |
| Blinding of participants and personnel (performance bias)
All outcomes |
Unclear risk |
The trial reported no information regarding this domain. |
| Blinding of outcome assessment (detection bias)
All outcomes |
Low risk |
The outcome of mortality allows a judgement of low risk of bias. Morbidity information was collected from the hospital database. The trial provided no information regarding the survey questionnaire. |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
The trial used intention‐to‐treat analysis and reported the exclusion of a small number of participants. |
| Selective reporting (reporting bias) |
Low risk |
No reporting bias was apparent. |
| Other bias |
Low risk |
No other biases identified. |
