Bennett 1994.

Methods	Single centre RCT, UK
Participants	Patients undergoing elective hip arthroplasty. Age range 54 to 89, mean 73, 30 male, 15 female Exclusions: grossly obese, malnourished, endocrine abnormalities, pyrexia
Interventions	1) No intraoperative warming 2) reflective insulation (Thermolite) 3) forced air warming
Outcomes	Aural canal temperature at end of procedure, transfusion as dichotomous data and mean (SD) transfusion in those transfused
Notes	All: IV crystalloid infusion at ambient temp (19‐21 ºC), blood warmed to 37 ºC
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Allocated randomly"
Allocation concealment (selection bias)	Unclear risk	"Allocated randomly"
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No blinding described
Blinding of outcome assessment (detection bias) Other outcomes	Unclear risk	No blinding described
Incomplete outcome data (attrition bias) All outcomes	Low risk	No loss to follow up
Selective reporting (reporting bias)	Unclear risk	No clear evidence
Other bias	Low risk	None expected