Additional results from RCTs and results from observational studies were reported in the review.
Twenty-three studies were included (n was at least 5,885 patients or central venous catheters): 13 RCTs (n=1,945), one non-randomised trial (n=154) and nine observational studies (n>3,786).
Study quality: One RCT reported allocation concealment, four reported blinding of analysis personnel, three used intention-to-treat analysis and six reported a sample size calculation.
Site of central venous catheter insertion (two studies): One RCT reported significantly higher rates of colonised catheters inserted through the femoral compared to the subclavian vein (p<0.001). One observational study reported no significant difference between internal jugular and axillary vein insertion.
Skin disinfectant (three studies): One RCT reported a significant reduction in colonisation associated with 2% aqueous chlorhexidine compared to 10% povidone iodine ( p=0.01), but no significant difference between 70% alcohol and 2% chlorhexidine. One RCT reported no significant difference between 10% povidone iodine and 0.5% chlorhexidine. One observational study reported significantly lower colonisation rates associated with alcoholic povidone iodine compared with aqueous povidone iodine (p<0.001).
Attachable cuffs (two studies): Triple-lumen catheters with attachable cuff (VitaCuff) were associated with a significant reduction in colonisation and a reduction in CRBSI compared to catheters with no cuff in one RCT (p=0.02), but no significant difference between interventions in one non-randomised study.
Studies reported no difference for catheter replacement at a new site versus exchange over a guidewire (one RCT), between different types of hubs and connectors (four RCTs) or between catheters with different numbers of lumens (two RCTs and two observational studies).
Educational programmes for healthcare professionals (one study): One pre-post study reported that an educational intervention was associated with a significant reduction in CRBSI from baseline,
Combined interventions (six studies): There was no significant difference between various combinations of silver-impregnated implantable collagen cuffs versus no cuff and a catheter removal policy at three or seven days (one RCT), or between different modes of catheter replacement and replacement schedules (one RCT). One observational study reported a significant reduction in catheter colonisation from baseline in a phased intervention (p=0.01), but no significant reduction in CRBSI. Two of three phased pre-post test studies that evaluated combinations of education, training, catheter policies and feedback reported significant reductions in CBRSI from baseline (p=0.0001 and p<0.001); one study found no significant reduction post-intervention.