Study Suggests Preoperative Surgical Screening for Asymptomatic Bacteriuria is Not Beneficial
Previous studies suggest that asymptomatic bacteriuria (ASB) is a risk marker for postoperative adverse events, such as surgical-site infection (SSI) and urinary tract infection (UTI). However, strong evidence that preoperative screening for bacteria in the urine, and treatment with antibiotics if found to be positive, improves clinical outcomes is lacking. Thus, it remains controversial whether to continue urine screening, which may lead to unnecessary antibiotic use, or to discontinue this common practice. This retrospective national cohort study sought to measure the association between ASB and key postoperative infectious outcomes, including SSI and UTI, and determine if directed antimicrobial therapy was associated with reduced rates of infection after major surgical procedures. To address the effectiveness of screening and treatment, investigators identified 68,265 Veterans who underwent cardiac, orthopedic, or vascular surgical procedures at 109 VA facilities from October 1, 2008, to September 30, 2013. Using national VA quality data from the Reporting, Analytics, Performance, Improvement and Deployment Program (RAPID) and the VA Surgical Quality Improvement Program (VASQIP), they examined outcomes in 17,749 patients who had preoperative urine cultures and the relationship between 30-day, post-operative SSI and UTI and pre-operative urine screening and treatment practices.
- Routine screening of preoperative urine cultures before major cardiac, orthopedic, and vascular surgical procedures was a low-yield clinical practice. ASB was identified in 4% of urine cultures, and after adjustments for other factors associated with postoperative infections (age, American Society of Anesthesiologists physical status class, smoking status, demographics, and diabetes status), Veterans with or without ASB had similar chances of surgical site infection (2.4% vs 1.6%).
- Antibiotic treatment of asymptomatic patients with ASB did not lead to improvement in any measurable postoperative clinical outcome. The incidence of SSI, UTI, and positive wound and urine culture results were the same in patients who were treated as in those who were untreated.
- This study – the largest and most robust to date – provides strong evidence that preoperative screening is of little value and should be discontinued as routine clinical practice. Findings support the approach of "Don't Test and Don't Treat" the urine in asymptomatic preoperative patients.
- The power of this study is limited by the small number of adverse outcomes, even in a cohort as large as this one.
This study was funded by HSR&D (IIR 12-103), and Dr. Branch-Elliman was supported by a Career Development Award from VISN 1. Drs. Branch-Elliman, O'Brien, and Gupta are part of HSR&D's Center for Healthcare Organization and Implementation Research (CHOIR).
Salazar J, O’Brien W, Strymish J, Itani K, Branch-Elliman W, and Gupta K. Association of Screening and Treatment for Preoperative Asymptomatic Bacteriuria with Postoperative Outcomes among US Veterans. JAMA Surgery. December 12, 2018; Epub ahead of print.