Palmer 1998.

Methods	Randomised controlled trial Single‐centre study, UK Dates enrolled: June to July 1997 Follow‐up: 4 months
Participants	18 participants, number of men not given Inclusion criteria: people whose haemoglobin concentration fell between 8 and 10 g/dL Exclusion criteria: not stated Age not given
Interventions	Liberal transfusion threshold vs. restrictive transfusion threshold. Participants were randomised when their postoperative haemoglobin concentration dropped to between 8 and 10 g/dL within the first 2 days post operation Liberal transfusion threshold: participants received a transfusion to raise their haemoglobin above 10 g/dL Restrictive transfusion threshold: participants did not receive a transfusion unless this perceived necessary by a clinician Number of participants randomised per intervention: 9/9 Number of participants included in the analysis of the primary outcome: not stated
Outcomes	None reported ‐ authors contacted, none available
Notes	We tried to contact any of the authors of this conference abstract and received an email response in January 2013 from one of the authors explaining that this was a pilot trial and that the authors were unsuccessfully in obtaining a grant to finish the trial. The study was only presented as a conference abstract. There was a small overlap of trial participants (either 2 or 4) with Carson 1998 (McClelland 2009) This study was not included in the analysis of data due to a lack of data reported in the manuscript
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient data to assess low or high risk of bias
Allocation concealment (selection bias)	Unclear risk	Insufficient data to assess low or high risk of bias
Blinding of participants (performance and detection bias)	Unclear risk	Insufficient data to assess low or high risk of bias
Blinding of personnel (performance bias)	Unclear risk	Insufficient data to assess low or high risk of bias
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient data to assess low or high risk of bias
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Insufficient information to assess as no outcome data reported
Selective reporting (reporting bias)	Unclear risk	Insufficient information to assess as no outcome data reported
Other bias	Unclear risk	Insufficient data to assess low or high risk of bias