Laine 2018.

Study characteristics
Methods	Design:  RCT, parallel 2‐arm trial Setting: university teaching hospital (Finland) Recruitment: June 2014 to December 2015 Maximum follow‐up: 7 days after hospital
Participants	Patients undergoing non‐emergency CABG, simple 1‐valve (aortico mitral) replacement, or both, requiring cardiopulmonary bypass (CPB) Liberal group: n = 40; M/F = 28/12; median (IQR) age = 64.5 (60.6‐68.3) years Restrictive group: n = 40; M/F = 29/11; median (IQR) age = 70.5 (67.8‐73.2) years
Interventions	Liberal group: transfused when Hb fell to < 10 g/dL Restrictive group: transfused when Hb fell to < 8.0 g/dL
Outcomes	ROTEM was performed at 3 predetermined time points: before anaesthesia induction, immediately after CPB/surgery, and on the first postoperative morning
Notes	Trial registration: after trial was registered at the Hospital District of Helsinki and Uusimaa (§94,9.05.2014) [sic] and receiving approval from the institutional Ethics Committee for Surgery in Helsinki University Hospital 2014 (D‐number 58/13/03/02/2014) Trial funding: this work was supported by a government grant for medical research and by the Finnish Angiological Society COI statement by investigators: "Dr. Laine has received congress related travel reimbursement from MSD Finland Oy. Dr. Schramko has received congress related travel reimbursement from TEM InternationalGmBH" (Laine 2018 p 132)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Randomization was done in blocks of 20" (Laine 2018 p 133) ‐ no further information given
Allocation concealment (selection bias)	High risk	"... using closed  envelopes" ‐ no further information given (Laine 2018 p 133)
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' Clinical staff blinded to ROTEM results
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'. Laboratory outcomes including ROTEM results are also considered hard outcomes
Blinding of outcome assessment (detection bias) Subjective measures	Low risk	No data from subjective outcomes (e.g. function)
Incomplete outcome data (attrition bias) All outcomes	Low risk	"All 80 patients were included in the analyses" (Laine 2018 p 134)
Selective reporting (reporting bias)	Unclear risk	Evidence of prospective registration/trial protocol unavailable; insufficient information to make a judgement
Other bias	Low risk	None evident