Is It Really the Foley? A Systematic Review of Bladder Management and Infection Risk

Background: The belief that intermittent catheterization results in fewer infections than indwelling catheters is commonly expressed in the spinal cord injury literature. Some practice guidelines strongly recommend intermittent over indwelling catheterization due to concerns about infections and other complications. However, studies on this topic are of low quality. Guidelines from the Consortium for Spinal Cord Medicine suggest the data regarding infection risk are mixed, and they do not recommend one bladder management method over the other. Objectives: To compare risk of bias in studies reporting higher rates of urinary tract infection (UTI) with indwelling catheters to studies that found equal rates of UTI between indwelling and intermittent catheterization, and to describe implications in clinical decision-making. Methods: A systematic search of PubMed, CINAHL, Embase, and SCOPUS databases from January 1, 1980, to September 15, 2020, was conducted. Eligible studies compared symptomatic UTI rates between indwelling and intermittent catheterization. We used a risk of bias assessment tool to evaluate each study. Results: Twenty-four studies were identified. Only three of these reported significantly higher UTI risk with indwelling catheters, and all three demonstrated a critical risk of bias. More than half of the studies reported differences in UTI risk of less than 20% between the two methods. Studies with larger (nonsignificant) differences favoring intermittent catheterization were more susceptible to bias from confounding. Conclusion: The hypothesis that indwelling catheters cause more UTIs than intermittent catheterization is not supported by the scientific literature. Most studies failed to demonstrate a significant difference in UTI risk, and studies with nonsignificant trends favoring intermittent catheterization were more susceptible to bias from confounding. Perceived risk of infection should not influence a patient's choice of catheter type.