Abstract: We included six RCTs (1539 participants) in this review. Trial sizes ranged from 50 to 703 participants. These six trials made four comparisons, namely: transparent dressings versus gauze; bordered transparent dressings versus a securement device; bordered transparent dressings versus tape; and transparent dressing versus sticking plaster. There is very low quality evidence of fewer catheter dislodgements or accidental removals with transparent dressings compared with gauze (two studies, 278 participants, RR 0.40; 95% CI 0.17 to 0.92, P = 0.03%). The relative effects of transparent dressings and gauze on phlebitis (RR 0.89; 95% CI 0.47 to 1.68) and infiltration (RR 0.80; 95% CI 0.48 to 1.33) are unclear. The relative effects on PVC failure of a bordered transparent dressing and a securement device have been assessed in only one small study and these were unclear. There was very low quality evidence from the same single study of less frequent dislodgement or accidental catheter removal with bordered transparent dressings than securement devices (RR 0.14, 95% CI 0.03 to 0.63) but more phlebitis with bordered dressings (RR 8.11, 95% CI 1.03 to 64.02) (very low quality evidence). A small single study compared bordered transparent dressings with tape and found very low quality evidence of more PVC failure with the bordered dressing (RR 1.84, 95% CI 1.08 to 3.11) but the relative effects on dislodgement were not clear (very low quality evidence). The relative effects of transparent dressings and a sticking plaster have only been compared in one small study and are unclear. More high quality RCTs are required to determine the relative effects of alternative PVC dressings and securement devices. It is not clear if any one dressing or securement device is better than any other in securing peripheral venous catheters. There is a need for further, independent high quality trials to evaluate the many traditional as well as the newer, high use products. Given the large cost differences between some different dressings and securement devices, future trials should include a robust cost-effectiveness analysis.

Plain-language summary: We searched the medical literature for studies that compared different types of products that are used to keep PVCs in place. We found six studies (involving 1539 participants) that compared four different ways of securing PVCs. These included: 1. a plain transparent film dressing compared with a gauze (woven fabric) dressing; 2. a bordered transparent dressing (clear transparent window with a reinforced fabric edge) compared with a securement device (that has anchor points or clips that hold the PVC in place over a strong adhesive base pad on the skin) that is used in conjunction with a transparent film dressing; 3. a bordered transparent dressing compared with non-sterile medical tape; 4. a plain transparent film dressing compared with sticking plaster. The participants in the studies were both adults and children on medical and surgical wards. There were no studies based in emergency departments. Two studies provided very low quality evidence that PVCs were less likely to fail when a transparent dressing was used rather than gauze. Other positive outcomes favouring one dressing over another were based on the results of very low quality, single studies. Overall there is a lack of high quality evidence and continued uncertainty regarding the best methods of securing a peripheral venous catheter remains. More high quality research is needed in this area. We assessed a number of quality indicators regarding the methods used in each study and graded the overall quality of studies as very low. Each study had a high or unclear risk of bias for some of the quality indicators. For example, it is likely that clinical staff responsible for assessing participants' outcomes knew the treatment group to which each person belonged, as the securement methods for PVCs looked different. There were only a limited number of studies available for consideration in this review, and they did not investigate some securement products that are in common use.