Smith 1988.

Methods	Randomised clinical trial, USA
Participants	34 hospitalised adults with major upper gastro‐intestinal surgery, at nutritional risk due to major surgery Male:Female = 27:7 Mean age = 67.5 years
Interventions	Experimental group: preoperative intravenous nutrition 10 days before surgery. Infusing 50 ‐ 60 kcal/kg/day of glucose/amino acid IVN mixture, containing 150 kcal/l g of nitrogen(n = 17) Control group: prepared for surgery in the usual manner and did not receive any preoperative nutritional support but were scheduled for the next convenient operating list(n = 17)
Outcomes	Mortality, major complications, serum transferrin, length of hospital stay
Study dates	Not stated
Notes	We contacted the authors in December 2015 by email: rsmith@med.usyd.edu.au. We received information regarding blinding and nutritional intake in the study group.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomly‐ordered cards
Allocation concealment (selection bias)	Unclear risk	Sealed envelopes were used, but they were not described as opaque.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding was not performed.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Blinding was not performed.
Incomplete outcome data (attrition bias) All outcomes	Low risk	There were no dropouts.
Selective reporting (reporting bias)	Low risk	The trial reported all‐cause‐mortality and serious adverse events.
For‐profit bias	Unclear risk	It was unclear how the trial was funded.
Other bias	Low risk	The trial appeared to be free of other components that could put it at risk of bias.