The authors of this review conclude after examination of data from a series of clinical trials, that the short-term use of silver alloy indwelling catheters in hospitalized adults reduces the risk of catheter acquired urinary tract infection. Your readers should be made aware however, that other authorities in the field have come to rather different conclusions from such a review. A contentious issue, central to the problem, is the definition of a catheter-associated urinary tract infection. The trials reported in the literature have generally used the mere presence of bacteria in the urine at various levels from >100/ml to >100,000/ml as the criteria of infection. Trautner et al. 1 were critical of this approach and expressed the view that clinical trials simply using bacteriuria, at whatever level, as the criterion for infection are fundamentally flawed. They considered that it is important to appreciate the distinction between urinary tract infection and asymptomatic bacteriuria in order to attempt a rational assessment of the evidence from these trials. The mere presence of bacteria in the urine of catheterized patients who are asymptomatic, is a quite different situation from that in which bacteria are present in the urine and the patient is exhibiting symptoms indicating that invasion of the tissues of urinary tract has occurred.
Johnson et al. 2 concluded that while the data from the clinical trials suggest that the silver alloy catheters might reduce the incidence of asymptomatic bacteriuria, they provide little or no insight into the effect of these catheters on symptomatic urinary tract infection, morbidity, secondary bloodstream infection, or mortality rates. Their view was that the clinical benefit and possible cost savings have yet to be demonstrated directly in a proper randomized trial because of lack of information on the clinically meaningful endpoints with these or any other antimicrobial catheter.
The poor quality of the clinical trials led Nie ยจl-Weise et al. 3 to the conclusion that there was insufficient evidence to support the use of the silver alloy catheters. They were critical of reviewers who drew conclusion from trials that had fundamental design problems, stating that analyses should only be based on the results from clinically homogeneous studies of high methodological quality.
The authors of the current review admit that their conclusions come from trials which were ''small and poor to