Sitges‐Serra 1985.

Methods	Randomized controlled trial
Participants	52 adult surgical patients undergoing PN through a subclavian catheter Appears to have been a hospital in Spain
Interventions	Administration set changes at 48 or 96 hours
Outcomes	IR‐BSI Catheter colonization CR‐BSI
Notes	Exclusions: not stated Central catheters: 100% PN: 100% Loss to follow‐up: not stated
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Inadequate random sequence generation; easily predictable Quote: "patients randomly assigned to one of two groups according to their hospital number" (p. 322)
Allocation concealment (selection bias)	High risk	Inadequate concealment; use of hospital number easily predictable
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not discussed, but not feasible in the study design
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not discussed, but not feasible in the study design
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Outcome blinding possible but not discussed
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Minimal information provided regarding attrition; no mention of missing samples
Selective reporting (reporting bias)	Low risk	No pre‐protocol
Other bias	Unclear risk	PN mean four days longer in group A (not statistically significant) No other demographic data presented