Darouiche 1999.

Methods	Multicentre RCT (USA)
Participants	Hospitalized adults who were at high risk for catheter‐related infection (such as people in ICUs or those who were immunocompromised) and were likely to require a CVC for 3 or more days were eligible for the study. Pregnant women and people with a history of allergy to any of the antimicrobial agents used for impregnating the catheters were excluded
Interventions	MR‐impregnated CVCs versus C‐SS‐impregnated CVCs
Outcomes	Catheter colonization, CRBSI and mortality attributed to CRBSI, premature catheter removal and adverse effects
Notes	The authors presented the outcomes separately for catheters in place for ≤ 7 days and > 7 days along with the overall outcomes. Sources of funding: partly from the industry (catheter manufacturer or distributor) and partly from institutional research fund
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Sequence generation was described in detail and appeared truly random: Quote: "A special randomization scheme was used to help match the two study groups closely. Catheter trays wrapped in identical folders were randomly assigned in blinded fashion according to computer‐generated identification numbers, in blocks of six (three from each group), so that the catheter trays would be removed from the box one at a time in the prescribed, random order from the top to the bottom. Blocks of six catheters were then shipped to the participating hospitals for assignment to specified patient care units.”
Allocation concealment (selection bias)	Low risk	From the statements above, the random sequence appeared to be centrally generated, i.e. away from the recruitment sites
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Quote: "In each case, the patients, nurses, physicians, and principal investigators who assessed the outcomes in each hospital were unaware of the type of catheter inserted.”
Blinding of outcome assessment (detection bias) Microbiological outcomes like catheter colonization	Low risk	Quote: "In each case, the patients, nurses, physicians, and principal investigators who assessed the outcomes in each hospital were unaware of the type of catheter inserted.”
Blinding of outcome assessment (detection bias) Clinical outcomes like CRBSI	Low risk	Quote: "In each case, the patients, nurses, physicians, and principal investigators who assessed the outcomes in each hospital were unaware of the type of catheter inserted.”
Incomplete outcome data (attrition bias) All outcomes	High risk	127/856 catheters (14.7%) were excluded from analysis (58 MR‐impregnated and 69 impregnated with C‐SS). The authors stated that the excluded samples had "similar patient and catheter characteristics". The catheters were excluded because they were not cultured, due to the following: " ... 84 were removed without notification of study coordinators, 19 were grossly contaminated during removal, and 24 were not available for other reasons" Although the excluded samples had similar characteristics across the 2 groups according to the authors, in view of the low event rates ‐ especially for the outcomes of CRBSI and mortality from CRBSI ‐ inclusion of these catheters might have altered the results significantly with or without assuming the worst‐case scenarios for either group
Selective reporting (reporting bias)	Low risk	All the major outcomes specified in the Methods, including catheter colonization and CRBSI, were reported in the Results
Other bias	Low risk	None identified