Blair 1986.

Study characteristics
Methods	Design: RCT, parallel 2‐arm, single‐site trial Setting: tertiary (university teaching hospital), London, UK Recruitment: not specified; pre‐1987 Maximum follow‐up: in‐hospital stay
Participants	50 consecutive participants with severe upper GI haemorrhage were randomised to 1 of 2 groups: Liberal group: n = 24; mean (SD) age = 64 (17.6) years Restrictive group: n = 26; mean (SD) age = 60 (17.8) years
Interventions	Liberal group: received at least 2 units of RBCs immediately at admission and during their first 24 hours in hospital Restrictive group: no transfused RBCs unless Hb was < 8.0 g/dL or shock persisted after initial resuscitation with Haemaccel
Outcomes	Blood usage (units), rebleeding, mortality, clotting times, Hct on admission/discharge, kaolin cephalin clotting time after 24 hours, impedance clotting time after 24 hours
Notes	Trial registration: not confirmed Trial funding: Crawley and Jersey Research Fund (UK) COI statement by investigators: none provided
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Investigators reported no information regarding this domain
Allocation concealment (selection bias)	Unclear risk	Investigators reported no information regarding this domain
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 outcome assessment (detection bias) Objective measures	Low risk	Blinding of mortality (the primary outcome used within this review) is not relevant, and we grade risk of bias as 'low'
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	There were no missing data (all data were collected during hospital stay)
Selective reporting (reporting bias)	Unclear risk	No reporting bias was apparent, but in the absence of prospective registration or a trial protocol, assessment must remain 'unclear'
Other bias	Low risk	No other biases identified