A prospective trial of a novel, silicone-based, silver-coated Foley catheter for the prevention of nosocomial urinary tract infections

Objective. To evaluate the efficacy of silicone- based, silver ion- impregnated urinary catheters in the prevention of nosocomial urinary tract infections (NUTIs). Design. Prospective, crossover study to compare the efficacy of a silicone- based, hydrogel- coated, silver- impregnated Foley catheter with that of a silicone- based, hydrogel- coated catheter in the prevention of NUTIs. Setting. Adult medical and surgical wards of a university teaching hospital. Results. A total of 3,036 patients with catheters were evaluated; 1,165 (38%) of the catheters were silver impregnated, and 1,871 (62%) were not silver impregnated. Study groups were not identical; there were more men, a shorter duration of catheterization, and fewer urine cultures per 1,000 catheter- days in the silver catheter group. The rate of NUTIs per 1,000 Foley- days was 14.29 in the silver catheter group, compared with 16.15 in the nonsilver catheter group (incidence rate ratio, 0.88; 95% confidence interval, 0.70- 1.11; P = .29). The median length of catheterization prior to the onset of a urinary tract infection (ie, exposure time) was 4 days for each group. There were no differences in the recovery of gram- positive, gram- negative, or fungal organisms in NUTIs. In a multivariate survival analysis, no factors, including silver catheters, were protective against NUTI. Conclusions. Unlike previous trials of latex-based, silver ion-impregnated Foley catheters, we found that silicone-based, silver-impregnated Foley catheters were not effective in preventing NUTIs; however, this study was affected by differences in the study groups. Prospective trials remain important in assessing the efficacy and cost-effectiveness of new silver-coated products.