Fan 2014.

Study characteristics
Methods	Design: RCT, parallel 2‐arm, single‐site trial Setting: tertiary (university teaching hospital), Nanjing, China Recruitment: October 2011 to May 2013 Maximum follow‐up: in‐hospital stay
Participants	192 randomised 186 participants analysed, 65 years of age or older, undergoing elective unilateral total hip replacement Liberal group: n = 92; mean (SD) age = 75 (6) years Restrictive group: n = 94; mean (SD) age = 73 (7) years
Interventions	Liberal group: received transfusion to maintain Hb > 10 g/dL Restrictive group: received transfusion with Hb < 8 g/dL or when symptoms of anaemia developed
Outcomes	Postoperative delirium, cerebrovascular accident, cardiac failure, myocardial infarction, pulmonary embolism, pneumonia, superficial wound infection, urinary tract infection, acute renal failure
Notes	Trial registration: none ascertainable Trial funding: work was supported by grants from the National Natural Science Foundation of China (No. 81300946) and the Natural Science Foundation of Jiangsu Province (BK2012778) COI statement by investigators: "there is no conflict of interest to be stated" (Fan 2014 p 184)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Patients were randomly assigned to the restrictive or liberal transfusion strategy group using a random number table and a sealed envelope technique" (Fan 2014 p 182)
Allocation concealment (selection bias)	Low risk	"Patients were randomly assigned to the restrictive or liberal transfusion strategy group using a random number table and a sealed envelope technique" (Fan 2014 p 182)
Blinding of participants and personnel (performance bias) Objective outcomes	Low risk	Blinding of personnel for this intervention was 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 outcome assessment was not described. Blinding of mortality (the primary outcome used within this review) is not relevant, and we graded risk of bias as 'low'. We have also considered outcomes such as pneumonia, requiring radiological investigations as a hard outcome
Blinding of outcome assessment (detection bias) Subjective measures	Low risk	Blinding of outcome assessment was not described for assessments of cognition and delirium. We considered risk of bias as low, given the structured assessment
Incomplete outcome data (attrition bias) All outcomes	Low risk	192 participants were randomised. Data were included for 94/96 in the restrictive group (2 excluded as declined transfusion). Data were included for 92/96 in the liberal group (4 excluded as declined transfusion)
Selective reporting (reporting bias)	Low 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 bias was apparent. Study sample size might be considered small for the outcomes