Chiarelli 1996.

Methods	RCT, single‐centre, 2‐arm, parallel design
Participants	Number of randomized participants: 24 Inclusion criteria People requiring artificial nutrition and able to use gastrointestinal tract for the purpose Exclusion criteria Not reported Primary diagnosis Multiple trauma Guillain‐Barré syndrome Intracerebral/subarachnoid bleed Gastric carcinoma Intestinal carcinoma Hypoxic coma Baseline characteristics EN group Age, mean (range): 52 (17 to 78) years Gender: not reported SAPS II, mean (SD): 10 (± 4) EN + PN group Age, mean (range): 49 (18 to 77) years Gender: not reported SAPS II, mean (SD): 11 (± 4) Country: Italy Setting: ICU
Interventions	EN group n = 12: no apparent losses Details: nutrition initiated 24 to 36 hours after admission. All participants fed with PN for 4 days, then 'weaned' to EN. Nasogastric tube placement, duration of feeding for 7 days, with formula consisting of high protein content with high ratio of calories/nitrogen. Caloric intake received, mean (SD): 33 (± 9) kcal/kg EN with PN group n = 12; no apparent losses Details: nutrition initiated 24 to 36 hours after admission. All participants given PN for 4 days, then given mixed feeding of 50% PN and 50% EN Caloric intake received, mean (SD): 31 (± 6) kcal/kg
Outcomes	Metabolic indices Incidence of diarrhoea (diagnosed by faecal mass of > 700 g/day) Nitrogen balance Infection (measured by blood cultures, chest x‐ray, and bronchoaspirates) Duration of mechanical ventilation LOS, mortality (time point not reported)
Notes	Funding/declarations of interest: not reported Study dates: not reported Study report published in Italian
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Participants randomly assigned to groups but no additional details
Allocation concealment (selection bias)	Unclear risk	No details
Blinding of participants and personnel (performance bias) All outcomes	High risk	No details and we assumed investigators made no attempts to blind personnel
Blinding of outcome assessment (detection bias) All outcomes (except mortality)	Unclear risk	No details
Blinding of outcome assessment (detection bias) Mortality	Low risk	No details. Lack of blinding unlikely to influence outcome data for mortality
Incomplete outcome data (attrition bias) All outcomes	Low risk	No apparent losses
Selective reporting (reporting bias)	Unclear risk	Clinical trial registration or publication of prospective protocol not reported; not feasible to judge risk of reporting bias
Baseline characteristics	Low risk	Study authors reported that baseline characteristics were comparable
Other bias	Unclear risk	No other sources of bias identified