Abstract: We included 22 studies involving 7436 participants comparing nine different types of securement device or dressing. All included studies were at unclear or high risk of performance bias due to the different appearances of the dressings and securement devices. The extent of blinding of outcome assessment was unclear in most studies. The quality of evidence varied between different comparisons and outcomes. We mainly downgraded the quality of evidence for imprecision, indirectness, risk of bias and inconsistency. It is unclear whether there is a difference in the rate of catheter-related BSI between securement with gauze and tape and standard polyurethane (SPU) (RR 0.64, 95% CI 0.26 to 1.63, low quality evidence), or between chlorhexidine gluconate-impregnated (CGI) dressings and SPU (RR 0.65, 95% CI 0.40 to 1.05, moderate quality evidence). There is high quality evidence that medication-impregnated dressings reduce the incidence of catheter-related BSI relative to all other dressing types (RR 0.60, 95% CI 0.39 to 0.93). There is moderate quality evidence that CGI dressings reduce the frequency of catheter-related BSI per 1000 patient days compared with SPU dressings (RR 0.51, 95% CI 0.33 to 0.78). There is moderate quality evidence that catheter tip colonisation is reduced with CGI dressings compared with SPU dressings (RR 0.58, 95% CI 0.47 to 0.73), but the relative effects of gauze and tape and SPU are unclear (RR 0.95, 95% CI 0.51 to 1.77, very low quality evidence). It is unclear if there is a difference in rates of skin irritation or damage when CGI dressings are compared with SPU dressings (moderate quality evidence) (RR 11.17, 95% CI 0.84 to 149.48). A multiple treatment meta-analysis found sutureless securement devices as likely to be the most effective at reducing the incidence of catheter-related BSI (low quality evidence), with CGI dressings ranked second (low quality evidence). Medication-impregnated dressing products reduce the incidence of catheter-related BSI relative to all other dressing types. There is some evidence that CGI dressings, relative to SPU dressings, reduce catheter-related BSI for the outcomes of frequency of infection per 1000 patient days, risk of catheter tip colonisation and possibly risk of catheter-related BSI. A multiple treatment meta-analysis found that sutureless securement devices are likely to be the most effective at reducing catheter-related BSI though this is low quality evidence. Most studies were conducted in intensive care unit (ICU) settings. More, high quality research is needed regarding the relative effects of dressing and securement products for CVCs. Future research may adjust the estimates of effect for the products included in this review and is needed to assess the effectiveness of new products.

Plain-language summary: The researchers searched medical databases up to September 2014, and identified 22 studies with a total of 7436 participants that were relevant to the research question. The studies investigated the following comparisons: - nine studies compared sterile gauze with standard polyurethane dressings; - six studies compared standard polyurethane dressings with chlorhexidine gluconate-impregnated dressings (chlorhexidine gluconate is an antibacterial disinfectant); - one study compared standard polyurethane dressings with silver-impregnated dressings (silver compounds may have antibacterial properties); - one study compared standard polyurethane dressings with hydrocolloid dressings; - one study compared 'modern' gas permeable standard polyurethane dressings with 'old' (original) standard polyurethane dressings; - one study compared highly adhesive transparent standard polyurethane dressings with chlorhexidine gluconate dressings; - one study compared standard polyurethane dressings with sutureless (stitchless) securement devices; - one study compared sterile gauze with no dressing; and - one study compared chlorhexidine gluconate dressings with no dressings. The included studies sometimes did not clearly report the methods they had used to minimise accidental or statistical error, but overall the methods were adequate. Analysis of the study results showed that there is high quality evidence that securing a CVC with a dressing impregnated with a medication (chlorhexidine gluconate-impregnated or silver) reduces catheter-related blood stream infection compared with a dressing without medication. The results indicated moderate quality evidence for a reduction in the frequency of catheter-related BSI per 1000 patient days (this is a unit used in research that represents patient use; in this case 1000 patient days is equal to 1000 patients using CVCs for one day, or 500 patients using CVCs for two days, or 250 patients using CVCs for four days, etc.) when a chlorhexidine gluconate-impregnated dressing was used rather than a standard polyurethane dressing. When the risk of infection with chlorhexidine gluconate-impregnated dressings was compared with the risk with standard polyurethane dressings in another way (by calculating the ratio of the risk of infection with one versus the other without taking account to patient days of use) this difference was less clear. A less direct measure of infection, that is the extent of bacterial colonisation of the tip of the catheter after removal, showed more bacteria with the standard polyurethane dressing (moderate quality evidence). The studies that contributed to this research were mainly carried out in intensive care unit settings, where a large number of CVCs are used for short durations. Other types of dressings and securement products for CVCs that were investigated by the studies analysed here did not show any observable effects on catheter-related BSI, catheter tip colonisation or any of the other outcomes assessed, such as skin irritation, failed catheter securement, condition of the dressing and patient death. More, high quality research is needed to investigate the relative effects of the wide range of dressing and securement products that are available for CVCs. This plain language summary is up-to-date as of 5th June, 2015.