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

Performance of Urinalysis Parameters in Predicting Urinary Tract Infection: Does One Size Fit All?

In a multihospital cohort study of 3392 patients, positive urinalysis parameters had poor positive predictive value for diagnosing urinary tract infection (UTI). Combined urinalysis parameters (pyuria or nitrite) performed better than pyuria alone for ruling out UTI. However, performance of all urinalysis parameters was poor in older women.

Diagnostic accuracy of dipsticks for urinary tract infections in acutely hospitalised patients: a prospective population-based observational cohort study

OBJECTIVE

To determine the added diagnostic value of dipsticks for urinary tract infections (UTI) in acutely hospitalised individuals.

DESIGN

Prospective population-based cohort study.

SETTING

North Denmark.

PARTICIPANTS

All adults (≥18 years) examined with dipsticks at emergency departments in North Denmark Region from September 20 through 23 October 2021.

MAIN OUTCOME MEASURES

UTI was defined as ≥1 symptom of new-onset frequency, dysuria or suprapubic tenderness combined with a positive urine culture. Positive dipsticks were defined as any reaction for leucocyte esterase and/or nitrite.

RESULTS

Dipsticks were used in 1052/2495 (42%) of acutely hospitalised patients with a median age of 73 years (IQR 57-82) and 540 (51%) were female. Overall, 89/1052 (8%) fulfilled the UTI criteria and urine cultures were done in 607/1052 (58%) patients. Among patients examined with both dipstick and urine culture, sensitivity and specificity for UTI were 87% (95% CI 78% to 93%) and 45% (95% CI 41% to 50%). Positive and negative predictive values were 21% (95% CI 17% to 26%) and 95% (95% CI 92% to 98%), whereas positive and negative likelihood ratios were 1.58 (95% CI 1.41 to 1.77) and 0.30 (95% CI 0.18 to 0.51). Pretest probabilities of UTI ranged from 29% to 60% in participants with specific UTI symptoms with corresponding post-test probabilities of 35-69% if dipsticks were positive and 12-27% if dipsticks were negative. Results remained comparable if final clinical diagnosis was used as outcome among all patients examined with dipsticks. Modified Poisson regression yielded an adjusted relative risk of 4.41 (95% CI 2.40 to 8.11) for empirical antibiotics for UTI in participants without specific UTI symptoms and a positive dipstick.

CONCLUSIONS

Dipsticks yielded limited clinical decision support compared with a symptom-driven approach in this study and were independently associated with excess antibiotics for UTI.

Propensity Score-Weighted Analysis of Postoperative Infection in Patients With and Without Preoperative Urine Culture

Importance

Although recent guidelines recommend against performance of preoperative urine culture before nongenitourinary surgery, many clinicians still order preoperative urine cultures and prescribe antibiotics for treatment of asymptomatic bacteriuria in an effort to reduce infection risk.

Objective

To assess the association between preoperative urine culture testing and postoperative urinary tract infection (UTI) or surgical site infection (SSI), independent of baseline patient characteristics or type of surgery.

Design, Setting, and Participants

This cohort study analyzed surgical procedures performed from January 1, 2017, to December 31, 2019, at any of 112 US Department of Veterans Affairs (VA) medical centers. The cohort comprised VA enrollees who underwent major elective noncardiac, nonurological operations. Machine learning and inverse probability of treatment weighting (IPTW) were used to balance the characteristics between those who did and did not undergo a urine culture. Data analyses were performed between January 2023 and January 2024.

Exposures

Performance of urine culture within 30 days prior to surgery.

Main Outcomes and Measures

The 2 main outcomes were UTI and SSI occurring within 30 days after surgery. Weighted logistic regression was used to estimate odds ratios (ORs) for postoperative infection based on treatment status.

Results

A total of 250 389 VA enrollees who underwent 288 858 surgical procedures were included, with 88.9% (256 753) of surgical procedures received by males and 48.9% (141 340) received by patients 65 years or older. Baseline characteristics were well balanced among treatment groups after applying IPTW weights. Preoperative urine culture was performed for 10.5% of surgical procedures (30 384 of 288 858). The IPTW analysis found that preoperative urine culture was not associated with SSI (adjusted OR [AOR], 0.99; 95% CI, 0.90-1.10) or postoperative UTI (AOR, 1.18; 95% CI, 0.98-1.40). In analyses limited to orthopedic surgery and neurosurgery as a proxy for prosthetic implants, the adjusted risks for UTI and SSI were also not associated with preoperative urine culture performance.

Conclusions and Relevance

This cohort study found no association between performance of a preoperative urine culture and lower risk of postoperative UTI or SSI. The results support the deimplementation of urine cultures and associated antibiotic treatment prior to surgery, even when using prosthetic implants.

Improving antimicrobial use through better diagnosis: The relationship between diagnostic stewardship and antimicrobial stewardship

Antimicrobial stewardship programs (ASPs) exist to optimize antibiotic use, reduce selection for antimicrobial-resistant microorganisms, and improve patient outcomes. Rapid and accurate diagnosis is essential to optimal antibiotic use. Because diagnostic testing plays a significant role in diagnosing patients, it has one of the strongest influences on clinician antibiotic prescribing behaviors. Diagnostic stewardship, consequently, has emerged to improve clinician diagnostic testing and test result interpretation. Antimicrobial stewardship and diagnostic stewardship share common goals and are synergistic when used together. Although ASP requires a relationship with clinicians and focuses on person-to-person communication, diagnostic stewardship centers on a relationship with the laboratory and hardwiring testing changes into laboratory processes and the electronic health record. Here, we discuss how diagnostic stewardship can optimize the "Four Moments of Antibiotic Decision Making" created by the Agency for Healthcare Research and Quality and work synergistically with ASPs.

Bedside nurses' antimicrobial stewardship practice scope and competencies in acute hospital settings: A scoping review

AIM

To identify and map bedside nurses' practice scope and competencies regarding antimicrobial stewardship in acute hospital settings, and develop a competency framework for them.

BACKGROUND

Antimicrobial stewardship requires multidisciplinary engagement including nursing. However, bedside nurses' antimicrobial stewardship practice scope and competencies in acute hospital settings remain unclear.

DESIGN

Scoping review.

METHODS

Using a five-stage framework proposed by Arksey and O'Malley and following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guidelines.

RESULTS

A total of 1422 records were retrieved, and 41 studies were included. In addition to the six practices recommended, this review summarized bedside nurses' contributions to five additional fields as well. Correspondingly, the competencies required by bedside nurses were summarized into eight domains: specialized knowledge, safety medication administration, leadership, education, diagnostic stewardship, infection prevention and control, professional development and professional quality.

CONCLUSION

Nurses' practice scope overlaps greatly with routine nursing practice in antimicrobial stewardship, confirming the evidence that nurses are ideal partners in antimicrobial stewardship. This review developed a competency framework at both basic and advanced levels. Among them, professional knowledge is the foundation, while professional quality motivates nurses to participate. In addition to competency assessment, it can also be used for training and human resource deployment based on seniority or professional level. This could bridge the knowledge gap and improve the engagement of nurses in heavy workload situations.

RELEVANCE TO CLINICAL PRACTICE

This practice scope will provide opportunities for nurses to engage in antimicrobial stewardship. Moreover, nursing competencies identified in this field could facilitate the development of competency-based education interventions, talent assessments, training and recruitment programs.

DATA RESOURCES

PubMed, EMBASE, Web of Science, CINHAL, PsycINFO, Cochrane Library, ProQuest and Scopus were searched from inception to November 2022, with an updated search in March 2023.

IMPACT

This scoping review provides evidence for best nursing practice scope and competency in antimicrobial stewardship in hospitals. However, it is also in line with the commitment of all nurses in the global community to combat antimicrobial resistance, which has become a global threat. An antimicrobial stewardship competency framework for bedside nurses was developed at both the basic and advanced levels. It would facilitate talent assessment, training, recruitment and human resource management by guiding the development of competency-based education interventions.

PATIENT OR PUBLIC CONTRIBUTION

No Patient or Public Contribution.

Current Pyuria Cutoffs Promote Inappropriate Urinary Tract Infection Diagnosis in Older Women

BACKGROUND

Pre-existing lower urinary tract symptoms (LUTS), cognitive impairment, and the high prevalence of asymptomatic bacteriuria (ASB) complicate the diagnosis of urinary tract infection (UTI) in older women. The presence of pyuria remains the cornerstone of UTI diagnosis. However, >90% of ASB patients have pyuria, prompting unnecessary treatment. We quantified pyuria by automated microscopy and flowcytometry to determine the diagnostic accuracy for UTI and to derive pyuria thresholds for UTI in older women.

METHODS

Women ≥65 years with ≥2 new-onset LUTS and 1 uropathogen ≥104 colony-forming units (CFU)/mL were included in the UTI group. Controls were asymptomatic and classified as ASB (1 uropathogen ≥105 CFU/mL), negative culture, or mixed flora. Patients with an indwelling catheter or antimicrobial pretreatment were excluded. Leukocyte medians were compared and sensitivity-specificity pairs were derived from a receiver operating characteristic curve.

RESULTS

We included 164 participants. UTI patients had higher median urinary leukocytes compared with control patients (microscopy: 900 vs 26 leukocytes/µL; flowcytometry: 1575 vs 23 leukocytes/µL; P < .001). Area under the curve was 0.93 for both methods. At a cutoff of 264 leukocytes/µL, sensitivity and specificity of microscopy were 88% (positive and negative likelihood ratio: 7.2 and 0.1, respectively). The commonly used cutoff of 10 leukocytes/µL had a poor specificity (36%) and a sensitivity of 100%.

CONCLUSIONS

The degree of pyuria can help to distinguish UTI in older women from ASB and asymptomatic controls with pyuria. Current pyuria cutoffs are too low and promote inappropriate UTI diagnosis in older women. Clinical Trials Registration. International Clinical Trials Registry Platform: NL9477 (https://trialsearch.who.int/Trial2.aspx?TrialID=NL9477).

Opportunities for antibiotic stewardship in emergency department or hospitalized patients with asymptomatic bacteriuria: identifying risk factors for antibiotic treatment

Antibiotic treatment of asymptomatic bacteriuria (ASB) is considered inappropriate and may lead to adverse events. This 2-center, retrospective cohort study including emergency department or inpatient adults identified pyuria (odds ratio, 2.43; 95% confidence interval, 1.17–5.01; P = .02) as the only independent risk factor for antibiotic treatment of ASB.

Prospective assessment of catheter-associated bacteriuria clinical presentation, epidemiology, and colonization dynamics in nursing home residents

BACKGROUND

Catheterization facilitates continuous bacteriuria, for which the clinical significance remains unclear. This study aimed to determine the clinical presentation, epidemiology, and dynamics of bacteriuria in a cohort of long-term catheterized nursing home residents.

METHODS

Prospective urine culture, urinalysis, chart review, and assessment of signs and symptoms of infection were performed weekly for 19 study participants over 7 months. All bacteria ≥ 1 × 10³ cfu/mL were cultured, isolated, identified, and tested for susceptibility to select antimicrobials.

RESULTS

In total, 226 of the 234 urine samples were polymicrobial (97%), with an average of 4.7 isolates per weekly specimen. A total of 228 urine samples (97%) exhibited ≥ 1 × 10⁶ CFU/mL, 220 (94%) exhibited abnormal urinalysis, 126 (54%) were associated with at least 1 possible sign or symptom of infection, and 82 (35%) would potentially meet a standardized definition of catheter-associated urinary tract infection (CAUTI), but only 3 had a caregiver diagnosis of CAUTI. Bacterial isolates (286; 30%) were resistant to a tested antimicrobial agent, and bacteriuria composition was remarkably stable despite a combined total of 54 catheter changes and 23 weeks of antimicrobial use.

CONCLUSION

Bacteriuria composition was largely polymicrobial, including persistent colonization by organisms previously considered to be urine culture contaminants. Neither antimicrobial use nor catheter changes sterilized the urine, at most resulting in transient reductions in bacterial burden followed by new acquisition of resistant isolates. Thus, this patient population exhibits a high prevalence of bacteriuria coupled with potential indicators of infection, necessitating further exploration to identify sensitive markers of true infection.

FUNDING

This work was supported by the NIH (R00 DK105205, R01 DK123158, UL1 TR001412).

Deconstructing the urinalysis: A novel approach to diagnostic and antimicrobial stewardship

The extensive use of the urinalysis for screening and monitoring in diverse clinical settings usually identifies abnormal urinalysis parameters in patients with no suspicion of urinary tract infection, which in turn triggers urine cultures, inappropriate antimicrobial use, and associated harms like Clostridioides difficile infection. We highlight how urinalysis is misused, and suggest deconstructing it to better align with evolving patterns of clinical use and the differential diagnosis being targeted. Reclassifying the urinalysis components into infectious and non-infectious panels and interpreting urinalysis results in the context of individual patient’s pretest probability of disease is a novel approach to promote proper urine testing and antimicrobial stewardship, and achieve better outcomes.

Quality Improvement Interventions and Implementation Strategies for Urine Culture Stewardship in the Acute Care Setting: Advances and Challenges

PURPOSE OF REVIEW

The goal of this article is to highlight how and why urinalyses and urine cultures are misused, review quality improvement interventions to optimize urine culture utilization, and highlight how to implement successful, sustainable interventions to improve urine culture practices in the acute care setting.

RECENT FINDINGS

Quality improvement initiatives aimed at reducing inappropriate treatment of asymptomatic bacteriuria often focus on optimizing urine test utilization (i.e., urine culture stewardship). Urine culture stewardship interventions in acute care hospitals span the spectrum of quality improvement initiatives, ranging from strong systems-based interventions like suppression of urine culture results to weaker interventions that focus on clinician education alone. While most urine culture stewardship interventions have met with some success, overall results are mixed, and implementation strategies to improve sustainability are not well understood.

SUMMARY

Successful diagnostic stewardship interventions are based on an assessment of underlying key drivers and focus on multifaceted and complementary approaches. Individual intervention components have varying impacts on effectiveness, provider autonomy, and sustainability. The best urine culture stewardship strategies ultimately include both technical and socio-adaptive components with long-term, iterative feedback required for sustainability.

Preoperative antibiotic therapy exceeding 7 days can minimize infectious complications after percutaneous nephrolithotomy in patients with positive urine culture

PURPOSE

To explore an appropriate duration of antibiotic therapy before percutaneous nephrolithotomy (PCNL) in patients with positive urine culture.

METHODS

From March 2016 to May 2018, consecutive patients with positive urine culture undergoing PCNL were prospectively registered. Initial preoperative antibiotics were given empirically. If needed, antibiotics were upgraded or adjusted to susceptible antibiotic after obtaining antibiotic-sensitivity test. Postoperative systemic inflammatory response syndrome (SIRS) was the primary outcome.

RESULTS

Among the 220 participants, the incidence of positive stone culture and SIRS were 85.5% and 36.8%. Escherichia coli (53.6%, 44.5%) and Proteus mirabilis (8.2%, 10.0%) were the top two bacteria in urine and stones. In univariable analysis, patients with postoperative SIRS had a higher rate of stone culture positivity (97.5% VS 78.4%, P < 0.001) and a shorter duration of preoperative antibiotics therapy (3.4 ± 2.7 days versus 4.2 ± 2.8 days, P = 0.037). The landscape of SIRS showed a declining trend as the elongation of preoperative antibiotics (P = 0.039). In a day-by-day comparison, SIRS was less prevalent in patients treated by pre-PCNL antibiotics ≥ 7 days than in those with antibiotics ≤ 6 days (21.7% VS 40.8%, P = 0.017). Multivariable logistic regression confirmed positive stone culture (P = 0.001, OR 11.115) as an independent risk factor and pre-PCNL antibiotics ≥ 7 days (P = 0.048, OR 0.449) as an independent protective factor for SIRS. Preoperative antibiotic ≥ 7 days decreased SIRS from 45.4 to 27.8% and from 9.1 to 0% in patients with a positive and negative stone culture, respectively.

CONCLUSION

Exceeding seven days should be appropriate duration of antibiotic therapy before PCNL in patients with positive urine cultures.

Enhanced antibiotic treatment based on positive urine dipstick infection test before percutaneous nephrolithotomy did not prevent postoperative infection in patients with negative urine culture

INTRODUCTION

Urinary tract infection (UTI) should be treated before percutaneous nephrolithotomy (PCNL). However, the most appropriate treatment strategy in patients with negative urine culture but positive urine dipstick infection test (positive urinary leukocyte or nitrite reaction) remains unclear.

METHODS

From August 2016 to February 2018, 806 consecutive patients who had undergone the first-stage PCNL with negative urine culture were included. Preoperative urinalysis, antibiotic treatment, intraoperative stone culture, and postoperative systemic inflammatory response syndrome (SIRS) were prospectively recorded. The primary outcome was SIRS. The impact of preoperative antibiotics on preoperative urinary tract infection, stone culture, and postoperative SIRS was studied.

RESULTS

Among the 806 participants, the rate of positive urine dipstick infection test and SIRS were 26.8% and 7.2%, respectively. In univariable analysis, positive urinary nitrite (p<0.001), positive urinary leukocytes (p<0.001), positive urine dipstick infection test (p<0.001), longer duration of pre-PCNL antibiotics (p=0.001), higher level of pre-PCNL antibiotics (p=0.010), infection stones (p=0.001), and positive stone culture (p<0. 001) were risk factors for SIRS. However, multivariable analysis showed that positive stone culture (p=0.004) and prolonged preoperative treatment with antibiotics (p=0.021) were independent risk factors for SIRS. Although preoperative antibiotics reduced the incidence of positive urine leukocyte (p<0.001) or nitrite reactions (p<0.001), prolonged or upgraded preoperative antibiotics did not affect the incidence of positive stone culture. Whether stone culture was positive (p=0.023) or negative (p=0.025), prolonged preoperative treatment with antibiotics was associated with a higher incidence of SIRS.

CONCLUSIONS

Enhanced preoperative antibiotic treatment based on positive urine dipstick infection tests was insufficient to reduce the incidence of positive stone culture but increased the risk of SIRS after PCNL in patients with negative urine cultures.