O'Brien 2010.

Methods	Design: RCT Operative phase: intraoperative Withdrawals: not stated Setting: 1 centre (USA) Sample size: 130 Funding: funded, in part, by an educational grant from Arizant Healthcare Inc.
Participants	Age (mean): 36 years Gender (M/F): 86/44 ASA grade: not stated Surgery type: elective (outpatient orthopaedic surgery: knee or shoulder) Surgery duration (mean): < 2 hrs (103 mins) Anaesthesia type: regional
Interventions	Intervention (ABSW): n = 58 Bair PAWS (Patient Adjustable Warming System) (Arizant Healthcare, Inc, Eden Prairie, MN) Duration (mean): not stated Temperature: 40 ± 3ºC on average Body area covered: not stated Control: n = 72 1 warmed blanket and 1 ambient‐temperature cotton blanket Duration (mean): not stated Co‐interventions: not stated Room temperature: not stated
Outcomes	Thermal comfort (VAS 0 ‐ 100) Other outcomes reported not included in the review: Anxiety (VAS 0 ‐ 100) Satisfaction with thermal comfort (VNRS 0 ‐ 100) Nurse's experience with the ease of use
Notes	Comparison 1
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated random numbers
Allocation concealment (selection bias)	Low risk	Sequentially‐numbered opaque sealed envelopes
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not reported
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Baseline comparability of groups	Low risk	To a high extent according to Table 1
Co‐interventions equal between groups	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	All randomized participants were analysed
Selective reporting (reporting bias)	Unclear risk	We did not have access to the protocol, therefore we cannot exclude risk of selective reporting with the information provided
Other bias	Low risk