Lotke 1999.

Study characteristics
Methods	Design: RCT, parallel 2‐arm, single‐site trial Setting: university hospital (Pennsylvania, USA) Recruitment: not specified Maximum follow‐up: 30 days
Participants	127 participants undergoing primary TKA who elected to pre‐donate blood 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	Liberal group: transfused with autologous blood immediately after TKA, beginning in the recovery room postoperatively Restrictive group: transfused with autologous blood when Hb had fallen to < 9.0 g/dL
Outcomes	Complications, cardiac events, Hb, blood usage (units), mental confusion, lethargy, orthostatic hypotension, number of participants transfused
Notes	Trial registration: none ascertainable Trial funding: none reported COI statement by investigators: no information reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	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) 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' Blinding of participants and personnel was not specified
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' Assessments were made by a person blinded to the group to which the participant was assigned
Blinding of outcome assessment (detection bias) Subjective measures	Low risk	Assessments were made by a person blinded 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	Evidence of prospective registration/trial protocol unavailable; insufficient information to make a judgement
Other bias	Low risk	No other biases were apparent