Role of noble metal-coated catheters for short-term urinary catheterization of adults: a meta-analysis

To evaluate the efficacy of noble-metal coated catheters in reducing catheter-associated urinary tract infections (CAUTI) in adult patients requiring short term catheterization. An electronic literature search of PubMed, BioMed Central, Embase, Scopus, CENTRAL (Cochrane Central Register of Controlled Trials) and Google scholar was carried out from inception to 10th October 2019. Any prospective study or randomized controlled trial (RCT) on adult patients comparing noble-metal coated urinary catheters with any standard catheter and evaluating the incidence of CAUTI or bacteriuria was included. A total of 13 studies were included in the systematic review. 12 were RCTs and one was a prospective cross-over trial. Catheters employed in the study group were grouped into two sub-groups: Silver alloy coated or Noble metal alloy-coated (Gold, Silver, and Palladium) catheters. Bacteriuria was the most commonly studied outcome variable across trials. Meta-analysis indicated that silver alloy-coated catheters (RR 0.63, 95%CI 0.44-0.90, P = 0.01; I2 = 72%) and noble metal alloy catheters (RR 0.58, 95%CI 0.41-0.81, P = 0.001; I2 = 0%) significantly reduce the risk of bacteriuria. Sub-group analysis based on the duration of catheterization demonstrated that silver alloy catheters reduce the risk of bacteriuria with >1week of catheterization (RR 0.46, 95%CI 0.26-0.81, P = 0.007; I2 = 63%). Symptomatic CAUTI was evaluated only in four studies with variable results. The quality of the included studies was not high. Our review indicates that bacteriuria may be reduced with the use of noble metal-coated catheters during short-term catheterization of adults, however, the quality of evidence is not high. It is not clear if these catheters reduce the risk of symptomatic CAUTI. Further homogenous RCTs are needed to provide clarity.