Doing the Right Thing for Asymptomatic Bacteriuria: Knowing Less Leads to Doing Less

Clinical practice guidelines are the preferred method among professional societies for defining safe and effective healthcare. Despite widespread dissemination by professional societies, the impact of guidelines on routine clinical practice remains suboptimal [1]. The Infectious Diseases Society of America guidelines for asymptomatic bacteriuria (ASB) are a particularly salient example [2], with one-third to two-thirds of patients with ASB inappropriately receiving treatment with antimicrobial agents [3, 4]. Urine cultures are often ordered reflexively when patients are admitted to the hospital or have any change in status in long-term care, regardless of the absence of urinary symptoms [3–5]. Clinicians react to positive results on these cultures by prescribing unnecessary antimicrobial agents, frequently swayed by guidelinesdiscordant cognitive biases regarding older age and frailty, pyuria on urinalysis, and the particular types of bacterial organisms (eg, gram-negative rods) on urine culture results [3, 5]. In this context, the very simple intervention by Leis et al [6] published in this edition of Clinical Infectious Diseases is particularly elegant. The authors explored the effectiveness of suppressing reporting of urine culture results when ordered for noncatheterized patients. Instead of receiving urine culture results as the default option, clinicians received a standardized statement declaring, “The majority of positive urine cultures from inpatients without an indwelling urinary catheter represent asymptomatic bacteriuria” [6]. They were encouraged to call the microbiology laboratory if they “strongly suspected” a urinary tract infection. The positive results of this study are provocative on many levels. First, they confirm the significantly higher prevalence of ASB (86%) vs urinary tract infections (14%) among the 74 cultures from patients without urinary catheters. Second, in patients whose urine cultures were reported openly, as per the standard approach, nearly half of all patients with confirmed ASB received antibiotics. Third, the intervention design had a strong effect on clinician behavior. When the default of reporting culture results was removed, the rate of guidelinesdiscordant treatment for ASB dropped from 48% to 12%, and clinicians called the microbiology laboratory for only 14% (5 of 37) of suppressed culture results. Only 4 urinary tract infections occurred in noncatheterized patients, and in each of these cases clinicians had empirically started therapy, with the presumption that clinically significant symptoms of urinary tract infection were present. Furthermore, no untreated patients had clinically significant signs of sepsis or urinary tract infection 72 hours after urine culture collection. The study has limitations that should be addressed prior to conducting a large-scale evaluation. The investigators acknowledge that they studied a small sample of patients and clinicians at only one institution. The rationale for using patients with urinary catheters as the comparison group to the intervention sample of noncatheterized patients is not clear. Treatment decisions may differ between these groups in ways that are better explained by clinical factors rather than customary and default decision errors. Finally, any large-scale intervention Received 13 December 2013; accepted 29 December 2013; electronically published 26 February 2014. Correspondence: Barbara Trautner, MD, PhD, Houston Health Services Research and Development Center of Excellence (152), Michael E. DeBakey VAMC, 2002 Holcombe Blvd, Houston, TX 77030 (trautner@bcm.edu). Clinical Infectious Diseases 2014;58(7):984–5 Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. Thiswork iswritten by (a) US Government employee(s) and is in the public domain in the US. DOI: 10.1093/cid/ciu011