Lotke 1999.

Methods	Randomised controlled trial
Participants	152 participants undergoing primary total knee arthroplasty (TKA) were randomly assigned to 1 of 2 groups: Liberal group: n = 65; M/F = 19/46; mean age = 69.7 years Restrictive group: n = 62; M/F = 20/42; mean age = 68.7 years
Interventions	The liberal group were transfused autologous blood immediately after TKA, beginning in the recovery room postoperatively. The restrictive group were transfused autologous blood when the Hb level had fallen to < 9.0 g/dL.
Outcomes	Complications, cardiac events, Hb levels, blood usage (units), mental confusion, lethargy, orthostatic hypotension, number of participants transfused
Notes	‐
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The trial used a computer random number generator.
Allocation concealment (selection bias)	Unclear risk	Allocation concealment was not reported.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Blinding of participants and personnel was not specified.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Assessments were made by a person blind to the group to which the participant was assigned.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Outcome data appear to have been complete.
Selective reporting (reporting bias)	Low risk	No reporting bias was apparent.
Other bias	Low risk	No other biases were apparent.