How Testing Drives Treatment in Asymptomatic Patients: Level of Pyuria Directly Predicts Probability of Antimicrobial Prescribing.

BACKGROUND: Urinalysis is a readily available test often used for screening. Pyuria is a common finding in asymptomatic patients; however, it is unknown how often identification of pyuria in the absence of confirmatory cultures leads to antimicrobial prescribing. The objective of this study was to measure the association between pyuria and antimicrobial initiation during the perioperative period and assess harms versus benefits of treatment. METHODS: A retrospective cohort of preoperative patients within the national healthcare system during the period 1 October 2008-30 September 2013 who had a urinalysis performed during the 30-day preoperative period was created; patients with positive urine cultures were excluded. The primary exposure was pyuria on preoperative urinalysis. The primary outcome was antimicrobial initiation. Secondary outcomes included postoperative surgical site (SSI), urinary tract (UTI), and Clostridioides difficile infections. Trend and logistic regression analyses were performed. RESULTS: Among 41 373 patients, 3617 had pyuria. 887 (24.5%) patients with pyuria received antimicrobials versus 1918 (5.1%) patients without pyuria. As the degree of pyuria increased, the odds of receiving antimicrobials also increased linearly (low, 14.7%; moderate, 24.0%; high pyuria, 37.4%). Preoperative pyuria was associated with postoperative C. difficile infections (aOR, 1.7; 95% CI, 1.2-2.4); risk was higher in patients who received antimicrobials (aOR, 2.4; 1.7-3.4). Pyuria was not associated with SSI but was associated with increases in UTI after orthopedic and vascular procedures; this risk was not mitigated by antimicrobial therapy. CONCLUSIONS: Urine screening during the preoperative period is a low-value intervention that increases antimicrobial exposure but does not improve postoperative outcomes.

Association of Screening and Treatment for Preoperative Asymptomatic Bacteriuria With Postoperative Outcomes Among US Veterans.

Importance: Limited data suggest that screening for asymptomatic bacteriuria (ASB) prior to nonurologic procedures is not useful. However, high-quality evidence to support consensus recommendations and influence clinical practice is lacking. Objective: To characterize the association between detection and treatment of preoperative ASB and postoperative outcomes. Design, Setting, and Participants: This retrospective cohort study involved patients, predominantly male veterans, who underwent surgical procedures in 109 US facilities within the US Department of Veterans Affairs health care system from October 1, 2008, to September 30, 2013. Participants included patients (n = 68 265) who had cardiac, orthopedic, or vascular surgical procedures. Each received a planned clinician review of complete medical records for antimicrobial prophylaxis as well as 30-day surgical-site infection (SSI) and urinary tract infection (UTI) outcomes, and each had a preoperative urine culture result available within the 30 days prior to the procedure. Data analysis was performed from December 2016 to August 2018. Main Outcome and Measures: The primary outcome was the association between preoperative ASB and postoperative SSI. The secondary outcomes included postoperative UTI and the association between antimicrobial therapy for ASB and postoperative infectious outcomes. Results: In total, 68 265 patients (65 664 [96.2%] were men and 2601 [3.8%] were women, with a mean [SD] age of 64.6 [9.2] years) were identified, and 17 611 (25.8%) were eligible for inclusion in the primary analysis. Preoperative urine cultures were performed in 17 749 (26.0%) patients, and the results were positive in 755 (4.3%), of which 617 (81.7%) were classified as ASB. With adjustments for age, American Society of Anesthesiologists class, smoking status, race/ethnicity, sex, and diabetes status, patients with or without ASB had similar odds of SSI (2.4% vs 1.6%; adjusted odds ratio [aOR], 1.58; 95% CI, 0.93-2.70; P = .08). Receipt of antimicrobial therapy with activity against the ASB organism was not associated with a reduced SSI risk (aOR, 1.01; 95% CI, 0.28-3.65; P = .99). Urinary tract infection occurred in 14 (3.3%) of 423 patients with ASB and 196 (1.5%) of 12 913 patients without ASB (aOR, 1.42; 95% CI, 0.80-2.49; P = .22). Treatment or prophylaxis for the ASB organism similarly was not associated with reduced odds of postoperative UTI (aOR 0.68; 95% CI, 0.20-2.30; P = .54). The ASB organisms matched a postoperative wound culture in 2 cases, both Staphylococcus aureus. Conclusions and Relevance: The findings of this study suggest that receipt of antimicrobial therapy with activity against ASB organisms identified in preoperative urine cultures was not associated with reductions in the risk for postoperative infections, including UTI and SSI; such findings suggest there is evidence for discontinuing the practice of screening and treatment for preoperative ASB.