Domain	Risk of bias			Support for judgement	Location in text
	Low risk	High risk	Unclear
Random sequence generation(selection bias)
Allocation concealment (selection bias)
Blinding of patients (performance bias) All outcomes
Blinding of personnel(performance bias) All outcomes
Blinding of outcome assessor(detection bias) – 1. wound infections
Blinding of outcome assessor(detection bias) – 2.intraabdominal abscesses
Blinding of outcome assessor(detection bias) – 3. postoperative complications e.g. acute myocardial infarction, postop thrombosis or pneumonia
Blinding of outcome assessor(detection bias) – 4. anastomotic leakage/dehiscence
Blinding of outcome assessor(detection bias) – 5. mortality within 30 days postop
Blinding of outcome assessor(detection bias) – 6. adverse events such as nausea, vomiting, abdominal distention, aspiration, tube blockage and any other adverse events
Blinding of outcome assessor 7. (Length of Hospital Stay)
Incomplete outcome data (attrition bias, intention to treat and as‐treated analysis)
Selective outcome reporting?(reporting bias)
Other bias
Notes: