Blight 1998.

Methods	Randomized controlled trial
Participants	769 ICU patients with a CVC containing crystalloids, PN, lipid or drugs. ICU, Australia
Interventions	Administration set changes at 72 or 120 hours
Outcomes	Catheter colonization CR‐BSI
Notes	Exclusions: CVCs inserted by other institutions Central catheters: 100% PN: mixed (proportion unknown) Loss to follow‐up: 36%
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Adequate random sequence generation method; computer generated
Allocation concealment (selection bias)	Unclear risk	Not discussed Quote: "Randomised on day 3/5 by an independent person" (abstract)
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not discussed, not feasible because of research design
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not discussed, not feasible because of research design
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Minimal information discussed, "independent microbiologist" for primary and secondary outcomes
Incomplete outcome data (attrition bias) All outcomes	High risk	Large dropout rate resulting around 30% of tips not cultured; 437/1206 The rate of attrition was similar in both groups
Selective reporting (reporting bias)	Unclear risk	Conference abstract only, never published No pre‐protocol Lumen culture performed but not reported