Tuominen 1981.

Methods	Single‐centre RCT (Finland) Study period:not reported. Setting: ICU
Participants	Adult inpatients admitted to ICU who required a CVC. No exclusion criteria stated Number of participants:136 Number of catheters; 136 (124 analysed) Age: not reported Sex: not reported
Interventions	Skin antisepsis applied prior to CVC insertion and regularly thereafter. Intervention A: chlorhexidine 0.05% added to the sterile gauze and applied at the CVC insertion site twice daily Intervention B: sterile gauze application without chlorhexidine
Outcomes	Septicaemia Catheter colonisation Adverse effects Number of patients on antibiotics during the in‐dwelling time of the catheters Outcomes assessed at various points during in‐patient stay.
Notes	No adverse effects were recorded in either group, so we do not include the data in our analysis. Funding source: not stated.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	'Patients and methods': The patients were "randomly allocated to one of two groups".
Allocation concealment (selection bias)	Unclear risk	Not adequately described
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not stated in the paper, but blinding appears unlikely as the trial involved a comparison between the application of chlorhexidine‐soaked gauze versus a dry sterile gauze.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Blinding of microbiological outcome assessor not reported
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	The authors did not provide information on the initial number of patients and catheters recruited or the eventual number analysed.
Selective reporting (reporting bias)	Low risk	The outcomes were not defined in the 'Methods'. However, authors reported all major outcomes, including septicaemia, catheter colonisation and adverse effects, in sufficient detail.
Other bias	Low risk	None identified