CVC colonization: Pooled data includes Dimick and Guillou and Bijma’s post-intervention CVC colonisation data. Pawar and Gunst failed to record CVC colonisation incidence as part of their respective studies. PICC colonization: As Gunst and Miyagaki failed to record PICC colonisation incidence as part of their respective studies; we have no pooled PICC colonisation data. CVC CRBSI: We pooled the CVC-related bloodstream infection data from Bijma’s post-intervention group, Sandoe, Pawar, Guillou and Gunst’s studies. PICC CRBSI: We pooled Gunst and Miyagaki’s PICC-related bloodstream infection data. Excluded data: Bijma’s pre-intervention data was excluded from the pooled data as it established the baseline colonisation and infection incidence by which the efficacy of the intervention was measured in the post-intervention group. Dimick’s mixed catheter bloodstream infection data (that included 348 pulmonary artery catheters) was excluded from the pooled data, as we were unable to extract the CVC-related bloodstream infection incidence. Sandoe’s mixed colonisation data (that included 4 arterial catheters) was excluded from the pooled data, as we were unable to extract data relating to CVC colonisation incidence and catheter days.