Urinalysis in acute care of adults: pitfalls in testing and interpreting results

Outcomes of patients with bacteriuria/pyuria of clinically undetermined significance (BPCUS) treated with antibiotics in 23 community hospital emergency departments

The optimal management of bacteriuria/pyuria of clinically undetermined significance (BPCUS) is unknown. Among 220 emergency department patients prescribed antibiotics for BPCUS, we found frequent readmissions, which were mitigated by outpatient follow-up visits. Observation and follow-up for an unknown diagnosis should be emphasized over antibiotics due to high likelihood of readmissions.

Impact of a Multifaceted Intervention on Antibiotic Prescribing for Cystitis and Asymptomatic Bacteriuria in 23 Community Hospital Emergency Departments

Background: Urinary tract infections (UTIs) are over-diagnosed and over-treated in the emergency department (ED) leading to unnecessary antibiotic exposure and avoidable side effects. However, data describing effective large-scale antimicrobial stewardship program (ASP) interventions to improve UTI and asymptomatic bacteriuria (ASB) management in the ED are lacking. Methods: We implemented a multifaceted intervention across 23 community hospital EDs in Utah and Idaho consisting of in-person education for ED prescribers, updated electronic order sets, and implementation/dissemination of UTI guidelines for our healthcare system. We compared ED UTI antibiotic prescribing in 2021 (post-intervention) to baseline data from 2017 (pre-intervention). The primary outcomes were the percent of cystitis patients prescribed fluoroquinolones or prolonged antibiotic durations (>7 days). Secondary outcomes included the percent of patients treated for UTI who met ASB criteria, and 14-day UTI-related readmissions. Results: There was a significant decrease in prolonged treatment duration for cystitis (29% vs 12%, P < .01) and treatment of cystitis with a fluoroquinolone (32% vs 7%, P < .01). The percent of patients treated for UTI who met ASB criteria did not change following the intervention (28% pre-intervention versus 29% post-intervention, P  = .97). A subgroup analysis indicated that ASB prescriptions were highly variable by facility (range 11%-53%) and provider (range 0%-71%) and were driven by a few high prescribers. Conclusions: The intervention was associated with improved antibiotic selection and duration for cystitis, but future interventions to improve urine testing and provide individualized prescriber feedback are likely needed to improve ASB prescribing practice.

Effecting the culture: Impact of changing urinalysis with reflex to culture criteria on culture rates and outcomes

OBJECTIVE

To evaluate the impact of changes to urinalysis with reflex to culture (UARC) reflex criteria on culture performance and clinical decision outcomes.

DESIGN

Retrospective study utilizing interrupted time series analysis from December 2018 to November 2020. Primary outcomes were measures of culture performance. Secondary outcomes were rates of antimicrobial prescription for suspected urinary tract infection (UTI) and catheter-associated urinary tract infection (CAUTI). We also assessed harmful events related to antimicrobial prescription for all causes and UTI, UTI symptoms, and sepsis.

SETTING

A 415-bed, academic, tertiary-care, medical center.

PATIENTS

Hospitalized adult patients with urine testing performed.

INTERVENTION

UARC reflex criteria were changed on October 22, 2019, from ≥5×109/L white blood cells (WBCs) or trace leukocyte esterase or positive nitrite units on urinalysis to only ≥15×109/L WBCs.

RESULTS

The study included 11,322 unique UARC tests. We detected a significant decrease in the rate of urine cultures performed from UARC after the intervention (32.5-8.7 cultures per 1,000 patient days; P < .001), with improved diagnostic efficacy (ie, culture positivity increased from 34.8% to 62.1%). CAUTI rates did not change. We detected a significant decrease in antimicrobial prescription rates (P = .05), this was primarily driven by preintervention changes. One case of sepsis occurred secondary to a missed UTI, and UTIs were rarely missed after the intervention.

CONCLUSIONS

Implementation of a stricter UARC reflex criterion was associated with a decrease in culture rates with improved diagnostic efficacy without significant adverse events. Continued education is needed to change antimicrobial prescribing practices.

Identification of novel factors associated with inappropriate treatment of asymptomatic bacteriuria in acute and long-term care

BACKGROUND

Chart reviews often fall short of determining what drove antibiotic treatment of asymptomatic bacteriuria (ASB). To overcome this shortcoming, we searched providers' free-text for documentation of their decision-making and for misleading signs and symptoms that may trigger unnecessary treatment of ASB.

METHODS

We reviewed a random sample of 10 positive urine cultures per month, per facility, from patients in acute or long-term care wards at 8 Veterans Affairs facilities. Cultures were classified as urinary tract infection (UTI) or ASB, and as treated or untreated. Charts were searched for 13 potentially misleading symptoms, and free-text documentation of providers' decision-making was classified into 5 categories. We used generalized estimating equations logistic regression to identify factors associated with ASB treatment.

RESULTS

One hundred fifty-eight (27.5%) of 575 ASB cases were inappropriately treated with antibiotics. Significant factors associated with inappropriate treatment included: abdominal pain, falls, decreased urine output, urine characteristics, abnormal vital signs, laboratory values, and voiding issues. Providers prescribed an average of 1.4 antimicrobials to patients with ASB, with cephalosporins (41%) and fluoroquinolones (21%) being the most common classes prescribed.

CONCLUSIONS

Chart reviews of providers' decision-making highlighted new factors associated with inappropriate ASB treatment. These findings can help design antibiotic stewardship interventions for ASB.

Is Low-value Testing Before Low-risk Hand Surgery Associated With Increased Downstream Healthcare Use and Reimbursements? A National Claims Database Analysis

BACKGROUND

Minor hand procedures can often be completed in the office without any laboratory testing. Preoperative screening tests before minor hand procedures are unnecessary and considered low value because they can lead to preventable invasive confirmatory tests and/or procedures. Prior studies have shown that low-value testing before low-risk hand surgery is still common, yet little is known about their downstream effects and associated costs. Assessing these downstream events can elucidate the consequences of obtaining a low-value test and inform context-specific interventions to reduce their use.

QUESTIONS/PURPOSES

(1) Among healthy adults undergoing low-risk hand surgery, are patients who receive a preoperative low-value test more likely to have subsequent diagnostic tests and procedures than those who do not receive a low-value test? (2) What is the increased 90-day reimbursement associated with subsequent diagnostic tests and procedures in patients who received a low-value test compared with those who did not?

METHODS

In this retrospective, comparative study using a large national database, we queried a large health insurance provider's administrative claims data to identify adult patients undergoing low-risk hand surgery (carpal tunnel release, trigger finger release, Dupuytren fasciectomy, de Quervain release, thumb carpometacarpal arthroplasty, wrist ganglion cyst, or mass excision) between 2011 and 2017. This database was selected for its ability to track patient claims longitudinally with direct provision of reimbursement data in a large, geographically diverse patient population. Patients who received at least one preoperative low-value test, including complete blood count, basic metabolic panel, electrocardiogram, chest radiography, pulmonary function test, and urinalysis within the 30-day preoperative period, were matched with propensity scores to those who did not. Among the 73,112 patients who met our inclusion criteria (mean age 57 ± 14 years; 68% [49,847] were women), 27% (19,453) received at least one preoperative low-value test and were propensity score-matched to those who did not. Multivariable regression analyses were performed to assess the frequency and reimbursements of subsequent diagnostic tests and procedures in the 90 days after surgery while controlling for potentially confounding variables such as age, sex, comorbidities, and baseline healthcare use.

RESULTS

When controlling for covariates such as age, sex, comorbidities, and baseline healthcare use, patients in the low-value test cohort had an adjusted odds ratio of 1.57 (95% confidence interval [CI] 1.50 to 1.64; p < 0.001) for a postoperative use event (a downstream diagnostic test or procedure) compared with those who did not have a low-value test. The median (IQR) per-patient reimbursements associated with downstream utilization events in patients who received a low-value test was USD 231.97 (64.37 to 1138.84), and those who did not receive a low-value test had a median of USD 191.52 (57.1 to 899.42) (adjusted difference when controlling for covariates: USD 217.27 per patient [95% CI 59.51 to 375.03]; p = 0.007). After adjusting for inflation, total additional reimbursements for patients in the low-value test cohort increased annually.

CONCLUSION

Low-value tests generate downstream tests and procedures that are known to provide minimal benefit to healthy patients and may expose patients to potential harms associated with subsequent, unnecessary invasive tests and procedures in response to false positives. Nevertheless, low-value testing remains common and the rising trend in low-value test-associated spending demonstrates the need for multicomponent interventions that target change at both the payer and health system level. Such interventions should disincentivize the initial low-value test and the cascade that may follow. Future work to identify the barriers and facilitators to reduce low-value testing in hand surgery can inform the development and revision of deimplementation strategies.

LEVEL OF EVIDENCE

Level III, therapeutic study.

The Five Ds of Outpatient Antibiotic Stewardship for Urinary Tract Infections

Urinary tract infections (UTI) are one of the most common indications for antibiotic prescriptions in the outpatient setting. Given rising rates of antibiotic resistance among uropathogens, antibiotic stewardship is critically needed to improve outpatient antibiotic use, including in outpatient clinics (primary care and specialty clinics) and emergency departments. Outpatient clinics are in general a neglected practice area in antibiotic stewardship programs, yet most antibiotic use in the United States is in the outpatient setting. This article provides a comprehensive review of antibiotic stewardship strategies for outpatient UTI in the adult population, with a focus on the "five Ds" of stewardship for UTI, including right diagnosis, right drug, right dose, right duration, and de-escalation. Stewardship interventions that have shown success for improving prescribing for outpatient UTI are discussed, including diagnostic stewardship strategies, such as reflex urine cultures, computerized decision support systems, and modified reporting of urine culture results. Among the many challenges to achieving stewardship for UTI in the outpatient setting, some of the most important are diagnostic uncertainty, increasing antibiotic resistance, limitations of guidelines, and time constraints of stewardship personnel and front-line providers. This article presents a stewardship framework, built on current evidence and expert opinion, that clinicians can use to guide their own outpatient management of UTI.

Optimal Urine Culture Diagnostic Stewardship Practice- Results from an Expert Modified-Delphi Procedure

BACKGROUND

Urine cultures are nonspecific for infection and often lead to misdiagnosis of urinary tract infection and unnecessary antibiotics. Diagnostic stewardship is a set of procedures that modifies test ordering, processing, and reporting in order to optimize diagnosis and downstream treatment. This study aimed to develop expert guidance on best practices for urine culture diagnostic stewardship.

METHODS

A RAND-modified Delphi approach with a multidisciplinary expert panel was used to ascertain diagnostic stewardship best practices. Clinical questions to guide recommendations were grouped in three thematic areas (ordering, processing, reporting) in practice settings of emergency department, inpatient, ambulatory, and long-term care. Fifteen experts ranked recommendations on a 9-point Likert scale. Recommendations on which the panel did not reach agreement were discussed in a virtual meeting, and a then second round of ranking by email was completed. After secondary review of results and panel discussion, a series of guidance statements was developed.

RESULTS

165 questions were reviewed with the panel reaching agreement on 104, leading to 18 overarching guidance statements. The following strategies were recommended to optimize ordering urine cultures: requiring documentation of symptoms, alerts to discourage ordering in the absence of symptoms, and cancelling repeat cultures. For urine culture processing, conditional reflex urine cultures and urine white blood cell as criteria were supported. For urine culture reporting, appropriate practices included nudges to discourage treatment under specific conditions and selective reporting of antibiotics to guide therapy decisions.

CONCLUSIONS

These 18 guidance statements can optimize use of the imperfect urine culture for better patient outcomes.

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.

Deceptive Urine Studies and Inappropriate Antibiotic Use in Geriatric Psychiatry: The Impact of Bundled Interventions

Background:

Indiscriminate orders for urinalysis and urine cultures (UC) drive inappropriate antibiotic treatment (Abx), especially in older adults with mental health disorders. Lack of data regarding the prevalence of and treatment for infections in acute geriatric psychiatric units (GPU) motivated us to initiate this project.

Aim:

Our goal was to improve urine test utilization and reduce unnecessary Abx for asymptomatic bacteriuria (ASB) and contaminated UC. Methods: This retrospective review and prospective evaluation of bundled interventions was conducted in a 22- bed GPU in a community-based teaching hospital. Four hundred twenty-seven (427) patient records were reviewed for Abx and indication and 157 patients were assessed for the impact of bundled interventions.

Results:

Near 27% received Abx, primarily for a misdiagnosed urinary tract infection. Only 20% met clinical criteria; 80% were unnecessarily treated for ASB or contaminated cultures. Over two-thirds of the Abx consisted of fluoroquinolones or trimethoprim-sulfamethoxazole, neither of which are recommended due to adverse events and/or resistance. The impact of bundled interventions was marginally effective.

Conclusion:

Urinalysis and UC are indiscriminately ordered in older adults, resulting in inappropriate Abx with non-recommended agents. Urinalysis should not be a requirement for admission in asymptomatic patients given the high prevalence of ASB and pyuria in older adults. There is an opportunity for more collaboration within referring networks to standardize best practice.

Envisioning Future UTI Diagnostics

Urinary tract infections (UTIs) are among the most common bacterial infections in the United States and are a major driver of antibiotic use - both appropriate and inappropriate - across healthcare settings. UTI treatment has become complex due to antibacterial resistance; one quarter of urinary tract isolates of Escherichia coli in the United States in 2017 were resistant to fluoroquinolones and one third to trimethoprimsulfamethoxazole (1), agents with historically predictable activity against E. coli. As a result, more broad-spectrum antibiotics are being used to treat UTIs, contributing to selection of further antibiotic resistance.

Correlation of Chemical Urinalysis to Microscopic Urinalysis and Urine Culture: Implications for Reflex Urinalysis Workflows

BACKGROUND

Urinalysis (UA) reflex testing approaches, which offer potential for savings in labor and result turnaround time, may rely on the performance of a chemical UA screen to determine which urine samples need microscopic UA and/or urine culture. We correlated chemical UA, microscopic UA, and urine culture results to determine the performance of chemical UA as a screening tool for reflex testing approaches.

METHODS

Consecutive UA results for 9127 tests (simultaneous chemical UA and microscopic UA) were retrospectively reviewed and correlated. Urine culture results were also correlated for 3127 samples that had urine culture ordered within 24 h of UA. Positivity criteria for each UA method were predefined.

RESULTS

Chemical UA yielded the following performance specifications for predicting microscopic findings: 93.0% sensitivity, 56.9% specificity, 64.7% positive predictive value, 90.5% negative predictive value. 3.2% of samples were negative by chemical UA but positive by microscopic UA. Of the samples with urine culture results available, 6.3% were negative by chemical UA but had clinically-significant positive urine cultures.

CONCLUSIONS

Reflex testing of microscopic UA and/or urine culture dependent from chemical UA results provides a feasible opportunity to reduce unnecessary testing.

Evaluation of a Novel Light Scattering Methodology for the Detection of Pathogenic Bacteria in Urine

BACKGROUND

Urine culture, the gold standard for detecting and identifying bacteria in urine, is one of the highest volume tests in many microbiology laboratories. The inability to accurately predict which patients would benefit from culture leads not only to monopolization of laboratory resources, but also to unnecessary antimicrobial exposure as patients receive empirical treatment for suspected or presumed urinary tract infections (UTI) while awaiting culture results. A common approach to decrease unnecessary urine culture is screening samples using urinalysis (UA) parameters to determine those that should proceed to culture (reflex). In this study, we compared the performance of a novel uropathogen detection method to urinalysis for purposes of UTI screening.

METHODS

Urine specimens submitted for culture (n = 194) were evaluated by urinalysis and a novel light scattering device (BacterioScan 216Dx UTI System) capable of detecting the presence of bacteria in urine. Sensitivity and specificity for prediction of a positive urine culture by UA and 216Dx were determined relative to urine culture results. A positive urine culture was defined as growth in culture of one or two uropathogens at concentrations of ≥50,000 CFU/mL.

RESULTS

194 urine samples were evaluated by UA, 216Dx, and urine culture. The 216Dx demonstrated a 100% [95%CI: 88.43%-100.0%] sensitivity and 81.71% [95%CI: 74.93%-87.30%] specificity for the detection of bacteriuria, vs UA with a sensitivity of 86.67% [95%CI 69.28%-96.24%] and specificity of 71.95% [95%CI: 64.41%-78.68%] when compared to urine culture (diagnostic reference method).

CONCLUSIONS

BacterioScan allows for an alternative method of screening with satisfactory sensitivity and improved specificity that may facilitate a reduction of unnecessary cultures. Additional studies are required to determine if a concomitant decrease in inappropriate antibiotic use can be realized with the 216Dx technology.

Antibiotic prescribing for adult bacteriuria and pyuria in community hospital emergency departments

OBJECTIVE

To describe emergency department (ED) antibiotic prescribing for urinary tract infections (UTIs) and asymptomatic bacteriuria (ASB) and to identify improvement opportunities.

METHODS

Patients treated for UTI in 16 community hospital EDs were reviewed to identify prescribing that was unnecessary (any treatment for ASB, duration >7 days for cystitis or >14 days for pyelonephritis) or suboptimal [ineffective antibiotics (nitrofurantoin/fosfomycin) or duration <7 days for pyelonephritis]. Duration criteria were based on recommendations for complicated UTI since criteria for uncomplicated UTI were not reviewed. 14-day repeat ED visits were evaluated.

RESULTS

Of 250,788 ED visits, UTI was diagnosed in 13,466 patients (5%), and 1427 of these (11%) were manually reviewed. 286/1427 [20%, 95% CI: 18-22%] met criteria for ASB and received 2068 unnecessary antibiotic days [mean (±SD) 7 (2) days]. Mean treatment duration was 7 (2) days for cystitis and 9 (2) days for pyelonephritis. Of 446 patients with cystitis, 128 (29%) were prescribed >7 days (total 396 unnecessary). Of 422 pyelonephritis patients, 0 (0%) were prescribed >14 days, 20 (5%) were prescribed <7 days, and 9 (2%) were given ineffective antibiotics. Overall, prescribing was unnecessary or suboptimal in 443/1427 [31%, 95% CI: 29-33%] resulting in 2464/11,192 (22%) unnecessary antibiotic days and 8 (0.5%) preventable ED visits.

CONCLUSIONS

Among reviewed patients, poor UTI prescribing in 16 EDs resulted in unnecessary antibiotic days and preventable readmissions. Key areas for improvement include non-treatment of ASB and shorter durations for cystitis.

Assessment of Prevalence and Cost of Care Cascades After Routine Testing During the Medicare Annual Wellness Visit

IMPORTANCE

For healthy adults, routine testing during annual check-ups is considered low value and may trigger cascades of medical services of unclear benefit. It is unknown how often routine tests are performed during Medicare annual wellness visits (AWVs) or whether they are associated with cascades of care.

OBJECTIVE

To estimate the prevalence of routine electrocardiograms (ECGs), urinalyses, and thyrotropin tests and of cascades (further tests, procedures, visits, hospitalizations, and new diagnoses) that might follow among healthy adults receiving AWVs.

DESIGN, SETTING, AND PARTICIPANTS

Observational cohort study using fee-for-service Medicare claims data from beneficiaries aged 66 years and older who were continuously enrolled in fee-for-service Medicare between January 1, 2013, and March 31, 2015; received an AWV in 2014; had no test-relevant prior conditions; did not receive 1 of the 3 tests in the 6 months before the AWV; and had no test-relevant symptoms or conditions in the AWV testing period. Data were analyzed from February 13, 2019, to June 8, 2020.

EXPOSURE

Receipt of a given test within 1 week before or after the AWV.

MAIN OUTCOMES AND MEASURES

Prevalence of routine tests during AWVs and cascade-attributable event rates and associated spending in the 90 days following the AWV test period. Patient, clinician, and area-level characteristics associated with receiving routine tests were also assessed.

RESULTS

Among 75 275 AWV recipients (mean [SD] age, 72.6 [6.1] years; 48 107 [63.9%] women), 18.6% (14 017) received at least 1 low-value test including an ECG (7.2% [5421]), urinalysis (10.0% [7515]), or thyrotropin test (8.7% [6534]). Patients were more likely to receive a low-value test if they were younger (adjusted odds ratio [aOR], 1.69 for ages 66-74 years vs ages ≥85 years [95% CI, 1.53-1.86]), White (aOR, 1.32 compared with Black [95% CI, 1.16-1.49]), lived in urban areas (aOR, 1.29 vs rural [95% CI, 1.15-1.46]), and lived in high-income areas (aOR, 1.26 for >400% of the federal poverty level vs <200% of the federal poverty level [95% CI, 1.16-1.37]). A total of 6.1 (95% CI, 4.8-7.5) cascade-attributable events per 100 beneficiaries occurred in the 90 days following routine ECGs and 5.4 (95% CI, 4.2-6.5) following urinalyses, with cascade-attributable cost per beneficiary of $9.62 (95% CI, $6.43-$12.80) and $7.46 (95% CI, $5.11-$9.81), respectively. No cascade-attributable events or costs were found to be associated with thyrotropin tests.

CONCLUSIONS AND RELEVANCE

In this study, 19% of healthy Medicare beneficiaries received routine low-value ECGs, urinalyses, or thyrotropin tests during their AWVs, more often those who were younger, White, and lived in urban, high-income areas. ECGs and urinalyses were associated with cascades of modest but notable cost.

Evaluation of urinary inflammatory index in rapid screening of urinary tract infection

The objective of this study was to assess the diagnosis value of urinary inflammatory index (UII) and systemic immune-inflammation index (SII) for UTI. Nine inflammatory indexes including neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, SII and six UIIs were calculated for Receiver operating characteristic curve analysis to select which one is suitable for the screening of UTIs or distinguishing the types of bacteria. UII3, which calculated from leucocyte esterase (LE), nitrite, white blood cells and bacteria, was preferentially used as an indicator for the diagnosis of UTI when the threshold was set at 0.53. UII2 was more suitable for the distinction between groups when the cutoff is set to 0.94. Appropriate urinary inflammation index calculated by rapid urinalysis of urine dipstick and urine sediment can help us to predict urinary tract infection and bacterial type, and reduce the workload and costs of urine culture.

Assessment of Testing and Treatment of Asymptomatic Bacteriuria Initiated in the Emergency Department

Background

Reducing antibiotic use in patients with asymptomatic bacteriuria (ASB) has been inpatient focused. However, testing and treatment is often started in the emergency department (ED). Thus, for hospitalized patients with ASB, we sought to identify patterns of testing and treatment initiated by emergency medicine (EM) clinicians and the association of treatment with outcomes.

Methods

We conducted a 43-hospital, cohort study of adults admitted through the ED with ASB (February 2018-February 2020). Using generalized estimating equation models, we assessed for (1) factors associated with antibiotic treatment by EM clinicians and, after inverse probability of treatment weighting, (2) the effect of treatment on outcomes.

Results

Of 2461 patients with ASB, 74.4% (N = 1830) received antibiotics. The EM clinicians ordered urine cultures in 80.0% (N = 1970) of patients and initiated treatment in 68.5% (1253 of 1830). Predictors of EM clinician treatment of ASB versus no treatment included dementia, spinal cord injury, incontinence, urinary catheter, altered mental status, leukocytosis, and abnormal urinalysis. Once initiated by EM clinicians, 79% (993 of 1253) of patients remained on antibiotics for at least 3 days. Antibiotic treatment was associated with a longer length of hospitalization (mean 5.1 vs 4.2 days; relative risk = 1.16; 95% confidence interval, 1.08-1.23) and Clostridioides difficile infection (CDI) (0.9% [N = 11] vs 0% [N = 0]; P = .02).

Conclusions

Among hospitalized patients ultimately diagnosed with ASB, EM clinicians commonly initiated testing and treatment; most antibiotics were continued by inpatient clinicians. Antibiotic treatment was not associated with improved outcomes, whereas it was associated with prolonged hospitalization and CDI. For best impact, stewardship interventions must expand to the ED.

Conditional reflex to urine culture: Evaluation of a diagnostic stewardship intervention within the Veterans' Affairs and Centers for Disease Control and Prevention Practice-Based Research Network

OBJECTIVE

In the absence of pyuria, positive urine cultures are unlikely to represent infection. Conditional urine reflex culture policies have the potential to limit unnecessary urine culturing. We evaluated the impact of this diagnostic stewardship intervention.

DESIGN

We conducted a retrospective, quasi-experimental (nonrandomized) study, with interrupted time series, from August 2013 to January 2018 to examine rates of urine cultures before versus after the policy intervention. We compared 3 intervention sites to 3 control sites in an aggregated series using segmented negative binomial regression.

SETTING

The study included 6 acute-care hospitals within the Veterans' Health Administration across the United States.

PARTICIPANTS

Adult patients with at least 1 urinalysis ordered during acute-care admission, excluding pregnant patients or those undergoing urological procedures, were included.

METHODS

At the intervention sites, urine cultures were performed if a preceding urinalysis met prespecified criteria. No such restrictions occurred at the control sites. The primary outcome was the rate of urine cultures performed per 1,000 patient days. The safety outcome was the rate of gram-negative bloodstream infection per 1,000 patient days.

RESULTS

The study included 224,573 urine cultures from 50,901 admissions in 24,759 unique patients. Among the intervention sites, the overall average number of urine cultures performed did not significantly decrease relative to the preintervention period (5.9% decrease; P = 0.8) but did decrease by 21% relative to control sites (P < .01). We detected no significant difference in the rates of gram-negative bloodstream infection among intervention or control sites (P = .49).

CONCLUSIONS

Conditional urine reflex culture policies were associated with a decrease in urine culturing without a change in the incidence of gram-negative bloodstream infection.

Diagnosis Between Chaos and Control: Affect and Hospital Clinicians' and Older Adult Patients' Narratives of Urinary Tract Infections

Research has observed that older adults are frequently overdiagnosed with urinary tract infection (UTI) and unnecessarily prescribed antibiotics in hospitals. In this article we explore the overlooked affective dimension of experiences of diagnosis and prescribing. Drawing on interviews with doctors, nurses and older adult patients (n = 41) on UTI diagnosis in two UK hospitals and Arthur Frank's work on illness narratives we identified two affective ways of experiencing diagnosis. Some clinicians and older adult patients articulated chaos narratives about being overwhelmed by contradictory evidence and events, doubting the repeated UTI diagnoses and courses of antibiotics but being unable to do anything about their concerns. Other clinicians and patients articulated control narratives about UTIs being frequently diagnosed and antibiotics prescribed to restore patients' health, echoing certainty and security, even if the processes described typically did not follow current guidance. We contend that analyzing the affective dimension offers conceptual insights that push forward sociological discussions on diagnosis as reflective or dogmatic in the context of the contradiction between acute care and chronic illnesses of old age. Our findings contribute practical ideas of why overdiagnosis and overprescribing happen in hospitals and complicate notions of patients pressuring for antibiotics. We also present methodological suggestions for analyzing how participants tell about their experiences in order to explore the typically not directly spoken affective dimension that influences thoughts and actions about diagnosis.

Impact of a pharmacist-driven education initiative on treatment of asymptomatic bacteriuria

PURPOSE

The results and methods of a pharmacist-driven multifaceted educational intervention on the appropriate management of asymptomatic bacteriuria (ABU) within an emergency department (ED) are reported.

METHODS

A retrospective, single-center cohort study was conducted to evaluate the effects of an educational intervention aimed at reducing the rates of mismanaged ABU within an ED at a Level 1 trauma center. The education involved a multifaceted approach directed by pharmacists and involved a handout and algorithm communicated through in-person discussions, emails, and general distribution. In order to evaluate the effectiveness of this education the preintervention and postintervention rates of inappropriate treatments were determined through a retrospective chart review. The primary outcome was the difference in the frequency of inappropriately treated ABU between the preintervention and postintervention periods.

RESULTS

A total of 268 patients were included in the study for review (134 in each group). There was a 16.5% reduction in the frequency of patients that had ABU inappropriately treated as a urinary tract infection in the postintervention period compared with the preintervention period (31 [23.1%] versus 53 [39.6%], p = 0.004).

CONCLUSION

Pharmacist-driven education was effecitive in reducing the rates of inappropriately used antibiotics for ABU within an ED.

The evaluation of early predictive factors for urosepsis in patients with negative preoperative urine culture following mini-percutaneous nephrolithotomy

PURPOSE

To identify early predictive factors for urosepsis secondary to mini-percutaneous nephrolithotomy (MPCNL) in patients with negative preoperative urine culture (UC).

METHODS

A total of 786 patients with baseline negative UC who underwent MPCNL between January 2017 and June 2019 were retrospectively analyzed. Urosepsis was defined according to the Sepsis-3 definition. Subsequently, perioperative potential risk factors were compared between non-urosepsis and urosepsis groups.

RESULTS

Despite negative UC in all patients, the rate of positive stone culture (SC) was 16.0%; the rate of pelvic urine culture (PUC) was 7.5%; 23 cases (2.9%) developed urosepsis after MPCNL. Univariate analysis showed that urosepsis was associated with the female gender, BMI, stone burden, diabetes mellitus and preoperative urine test. Multivariate logistic regression analysis suggested that urine test with positive nitrite and white blood cells and leukocyte esterase (N+WBC+LE+) (OR 17.51, 95% CI 6.75-45.38, P < 0.001) and operative time > 120 min (OR 3.53, 95% CI 1.41-8.85, P = 0.007) were independent risk factors for urosepsis. Additionally, receiver operating characteristic curve analysis of N+WBC+LE+ showed that the area under the curve was 0.785 for predicting the occurrence of urosepsis. Further analysis showed that N+WBC+LE+ provided an efficient prediction of SC+/PUC+ (SC+ or PUC+) with 61.7% sensitivity and 97.3% specificity.

CONCLUSIONS

In spite of the baseline negative preoperative UC, 2.9% of patients developed urosepsis after MPCNL. N+WBC+LE + was determined to be an early and efficient prediction of intraoperative bacterial status and urosepsis following MPCNL. Nevertheless, further studies are needed to confirm the results.

Dipstick analysis of urine chemistry: benefits and limitations of dry chemistry-based assays

Urinalysis is a commonly utilized laboratory test, and analysis of urine has been studied and used since ancient times. Urine contains a wide array of metabolites that can provide information regarding the current physiologic state of the body and clinical manifestations of disease. In this review, we discuss the mechanics of the dry chemistry component of the urine dipstick such as the reaction principles underlying various assays and potential effects of collection and storage on results. Additionally, we discuss the benefits and limitations of the urine dipstick as it pertains to its use as a low-cost tool in point-of-care settings and the reasoning for a lack of its use as a broad screening tool.

Is Dipstick Urinalysis Screening Beneficial in Men with Lower Urinary Tract Symptoms?

INTRODUCTION

Dipstick urinalysis is a widely used screening tool in the evaluation of men with lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH). As limited data support the use of dipstick urinalysis, we have used data from three recently published studies to assess clinical outcomes in those who had dipstick urinalysis findings for blood, glucose, and/or leukocytes.

METHODS

We analyzed data from three observational studies involving men interested in using over-the-counter tamsulosin: a self-selection study (SSS) and two actual-use studies of 8-week (AUS8) and 24-week (AUS24) durations. Subgroup analyses focused on pooled data from participants not using α-blockers or other prescription medication for LUTS suggestive of BPH (nonRx users) and who had urine dipstick findings. Data from participants using α-blockers (AUS8) or any prescription BPH medications (SSS and AUS24) are presented as reference.

RESULTS

Overall, 2488 nonRx users underwent dipstick urinalysis and 680 (27.3%) had positive findings including traces of blood (332; 13.3%), glucose (259; 10.4%), and/or leukocytes (245; 9.8%). Among users of prescription medicines, 21.6% (37/171) in SSS, 27.4% (23/84) in AUS8, and 31.1% (47/151) in AUS24 had urine dipstick findings. The 200 dipstick-positive nonRx users in SSS underwent per protocol urological assessment: 26 (13.0%) had a newly diagnosed condition causing/contributing to urinary symptoms of which 2.9% were identified as medically important conditions. Among nonRx users with or without a dipstick finding, medically important conditions reported included prostate cancer (1.0% vs. 1.0%, respectively) and urolithiasis (1.0% vs. 0.3%, respectively). The proportion of men with dipstick urinalysis findings was similar between men who regularly visited their physician and those who did not.

CONCLUSION

Dipstick urinalysis did not markedly increase the detection of undiagnosed medically important conditions that cause/contribute to urinary symptoms, suggesting that this test may not be a very effective screening tool for men with LUTS.

FUNDING

Boehringer Ingelheim Pharmaceuticals, Inc.

Diagnosis of urinary tract infection in older persons in the emergency department: To pee or not to pee, that is the question

Doreen is a 79-year-old woman referred by her general practitioner to the ED for intravenous antibiotics for a urinary tract infection (UTI). She lives in a residential aged care facility (RACF) and staff report malodourous and cloudy urine. She denies dysuria or frequency. On examination Doreen is frail with vital signs of: temperature 37.7°C, pulse 87 bpm, blood pressure 130/70; there is no suprapubic or flank tenderness. Do you perform a dipstick test on Doreen’s urine for a suspected UTI?

Gaps in communication between different staff groups and older adult patients foster unnecessary antibiotic prescribing for urinary tract infections in hospitals: a qualitative translation approach

Background

Studies have reported large scale overprescribing of antibiotics for urinary tract infection (UTI) in hospitalised older adults. Older adults often have asymptomatic bacteriuria, and clinicians have been found to diagnose UTIs inappropriately based on vague symptoms and positive urinalysis and microbiology. However, the joined perspectives of different staff groups and older adult patients on UTI diagnosis have not been investigated.

Methods

Thematic analysis of qualitative interviews with healthcare staff (n = 27) and older adult patients (n = 14) in two UK hospitals.

Results

Interviews featured a recurrent theme of discrepant understandings and gaps in communication or translation between different social groups in three key forms: First, between clinicians and older adult patients about symptom recognition. Second, between nurses and doctors about the use and reliability of point-of-care urinary dipsticks. Third, between nurses, patients, microbiologists and doctors about collection of urine specimens, contamination of the specimens and interpretation of mixed growth laboratory results. The three gaps in communication could all foster inappropriate diagnosis and antibiotic prescribing.

Conclusion

Interventions to improve diagnosis and prescribing for UTIs in older adults typically focus on educating clinicians. Drawing on the sociological concept of translation and interviews with staff and patients our findings suggest that inappropriate diagnosis and antibiotic prescribing in hospitals can be fuelled by gaps in communication or translation between different staff groups and older adult patients, using different languages and technologies or interpreting them differently. We suggest that interventions in this area may be improved by also addressing discrepant understandings and communication about symptoms, urinary dipsticks and the process of urinalysis.

Community-acquired Staphylococcus aureus bacteriuria: a warning microbiological marker for infective endocarditis?

Background

Urinary tract infection (UTI) is frequently diagnosed in the Emergency Department (ED). Staphylococcus aureus (SA) is an uncommon isolate in urine cultures (0.5–6% of positive urine cultures), except in patients with risk factors for urinary tract colonization. In the absence of risk factors, community-acquired SA bacteriuria may be related to deep-seated SA infection including infective endocarditis. We hypothesized that SA bacteriuria could be a warning microbiological marker of unsuspected infective endocarditis in the ED.

Methods

This is a retrospective chart review of consecutive adult patients between December 2005 and February 2018. All patients admitted in the ED with both SA bacteriuria (10⁴ CFU/ml SA isolated from a single urine sample) and SA bacteremia, without risk factors for UT colonization (i.e., < 1 month UT surgery, UT catheterization) were analyzed. Diagnosis of infective endocarditis was based on the Duke criteria.

Results

During the study period, 27 patients (18 men; median age: 61 [IQR: 52–73] years) were diagnosed with community-acquired SA bacteriuria and had subsequently documented bacteremia and SA infective endocarditis. Only 5 patients (18%) had symptoms related to UT infection. Median delay between ED admission and SA bacteriuria identification was significantly shorter than that between ED admission and the diagnosis of infective endocarditis (1.4 ± 0.8 vs. 4.3 ± 4.2 days: p = 0.01). Mitral and aortic valves were most frequently involved by infective endocarditis (93%). Mortality on day 60 reached 56%.

Conclusions

This study suggests that community-acquired SA bacteriuria should warn the emergency physician about a potentially associated left-sided infective endocarditis in ED patients without risk factors for UT colonization.

Overprescribing antibiotics for asymptomatic bacteriuria in older adults: a case series review of admissions in two UK hospitals

Background

Overdiagnosis and overtreatment of urinary tract infection (UTI) with antibiotics is a concern. In older adults, diagnosis of UTI using near-patient urine tests (reagent strip tests, dipsticks) is advised against because the age-related increase in asymptomatic bacteriuria can cause false-positive results. Instead, UTI diagnosis should be based on a full clinical assessment. Previous research lacks systematic information on urine dipstick use in hospitals. The aim of this study was to examine the use of urine dipstick tests and microbiology among older adult hospital admissions in relation to recommended UTI diagnostic criteria. A further aim was to assess factors associated with the use of dipsticks.

Methods

A case series review of patients aged ≥70 years admitted to two NHS Trust hospitals in England. Records from 312 patients admitted in 2015 meeting inclusion criteria were selected at random.

Results

Of 298 complete patient records, 54% had at least one urine dipstick test recorded. 13% (21/161) of patients who received a urine dipstick test were diagnosed as having a UTI, only 2 out of these 21 cases had two or more clinical signs and symptoms. 60 patients received a second dipstick test, leading to 13 additional cases of UTI diagnosis. Dipstick tests were more likely to be performed on patients with a history of falls (OR 1.93, 95% CI:1.21, 3.07, p < 0.01), and less likely on those with dementia (OR 0.44, 95% CI: 0.22, 0.87, p < 0.05). The most common reason for testing was routine admissions policy (49.1% of cases), but these cases were predominantly in one hospital.

Conclusions

Use of urine dipstick tests was high among older adults admitted to hospitals. Most cases were asymptomatic and therefore received inappropriate antibiotic therapy. This paper highlights the need to implement new Public Health England diagnostic guidelines to hospital admission and emergency departments.

The Role of the Hospital Epidemiologist in Antibiotic Stewardship

Antibiotic stewardship programs (ASPs) play a crucial role in controlling the emergence of resistant organisms, reducing rates of Clostridium difficile infections and associated hospital length of stay, promoting judicious use of antibiotics, and minimizing associated adverse events. There is a significant overlap between the goals of infection control programs and ASPs, and both programs can benefit from a synergistic relationship. Hospital epidemiologists can support these programs by providing leadership support, sharing surveillance data, bridging gaps between ASPs and departments such as microbiology, integrating educational programs with ASPs, sharing outbreak alerts, and assisting with the development of treatment algorithms.

Antimicrobial Resistance: An Antimicrobial/Diagnostic Stewardship and Infection Prevention Approach

Antimicrobial resistance (AR) is one of the most serious public health threats today, which has been accelerated by the overuse and misuse of antimicrobials in humans and animals plus inadequate infection prevention. Numerous studies have shown a relationship between antimicrobial use and resistance. Antimicrobial stewardship (AS) programs have been shown to improve patient outcomes, reduce antimicrobial adverse events, and decrease AR. AS programs, when implemented alongside infection control measures, especially hand-hygiene interventions, were more effective than implementation of AS alone. Targeted coordination and prevention strategies are critical to stopping the spread of multidrug-resistant organisms.

The Current State of Antimicrobial Stewardship: Challenges, Successes, and Future Directions

PURPOSE OF REVIEW

The aim of this study is to examine the current state of the field of antimicrobial stewardship (AS) by highlighting key challenges and successes, as well as exciting future directions.

RECENT FINDINGS

AS mandates from the Centers for Medicare and Medicaid (CMS) and the Joint Commission (TJC) will stimulate increased compliance with current AS standards, but overall compliance is currently poor. Key challenges to progress in the field of AS include insufficient workforce and monetary resources, poorly defined AS metrics, and much needed expansion beyond the inpatient hospital setting. Despite these challenges, massive progress has been made in the last two and a half decades since the field of AS emerged. AS metrics are rapidly evolving and transforming the way antimicrobial stewardship programs (ASPs) measure success. Rapid diagnostics and diagnostic test stewardship are proving to be extremely effective when coupled with an ASP. Telehealth may improve access to ASP expertise in resource poor settings, and the role of bedside nurses as ASP team members has the potential to greatly augment ASP efforts. Allergy testing as an ASP strategy remains largely underutilized. ASPs have made significant gains in the battle against antimicrobial resistance (AR), but considerable advancement is still needed. Awareness of current challenges is critical to ensure progress in the field. The field of AS is expanding and transforming rapidly through integration, technology, and improved processes.

Evaluation of the BacterioScan 216Dx for Standalone Preculture Screen of Preserved Urine Specimens in a Clinical Setting

Background

The BacterioScan 216Dx laser microbial growth monitoring system was evaluated as an option for preurine culture screening of preserved urine specimens at an acute care medical center.

Methods

The BacterioScan 216Dx system performance characteristics and the economic impact (cost effectiveness) for the laboratory were assessed. Urinalysis performance compared to urine culture was assessed if urinalysis was ordered as part of the patient care set.

Results

When compared to urine culture, the BacterioScan had an overall performance with corresponding 95% confidence intervals of 76% (68-83) sensitivity, 84% (80-87) specificity, 55% (48-63) positive predictive value, and 93% (90-95) negative predictive value for 610 randomly selected preserved urine specimens. Urinalysis compared to urine culture overall performance was 59% (48-69) sensitivity, 87% (83-90) specificity, 53% (43-63) positive predictive value, 89% (86-92) negative predictive value for 414 urine specimens.

Conclusions

While the system did improve the turnaround time to a negative report, adoption of the BacterioScan system would increase the reagent budget for laboratory urine culture by 2.34 times the current cost, potentially making BacterioScan prohibitive in a budget restricted environment. Additionally, performance when compared to traditional urine culture was less than acceptable for a diagnostic laboratory to use as a stand-alone urinary tract infection screen.

Leveraging Antimicrobial Stewardship in the Emergency Department to Improve the Quality of Urinary Tract Infection Management and Outcomes

Background

The complex and fast-paced emergency department (ED) practice setting presents unique challenges that demand a tailored approach to antimicrobial stewardship. In this article, we describe the strategies applied by 1 institution’s antimicrobial stewardship program (ASP) that were successful in improving prescribing practices and outcomes for urinary tract infection (UTI) in the ED.

Methods

Core strategies included pre-implementation research characterizing the patient population, antimicrobial resistance patterns, prescribing behavior, and morbidity related to infection; collaboration across multiple disciplines; development and implementation of a UTI treatment algorithm; education to increase awareness of the algorithm and the background and rationale supporting it; audit and feedback; and early evaluation of post-implementation outcomes.

Results

We observed a rapid change in prescribing post-implementation with increased empiric nitrofurantoin use and reduced cephalosporin use (P < .05). Our elevation of nitrofurantoin to firstline status was supported by our post-implementation analysis showing that its use was independently associated with reduced 30-day return visits (adjusted odds ratio, 0.547; 95% confidence interval, 0.312–0.960). Furthermore, despite a shift to a higher risk population and a corresponding decrease in antimicrobial susceptibility rates post-implementation, the preferential use of nitrofurantoin did not result in higher bug-drug mismatches while 30-day return visits to the ED remained stable.

Conclusions

We demonstrate that an outcomes-based ASP can impart meaningful change to knowledge and attitudes affecting prescribing practices in the ED. The success of our program may be used by other institutions as support for ASP expansion to the ED.

Impact of Urinalysis on Medical Decision-making and Length of Stay

Introduction

The emergency department (ED) is under pressure to meet length of stay (LOS) metrics for care in the ED. An aspect that we propose affects LOS is the order for urine sample collection and subsequent urinalysis (UA) as both are time consuming steps. This project’s primary goals are to determine if ordering a UA increases LOS and how often UA contributes to clinical decision-making and/or disposition decisions in the ED. Secondary objectives were to identify factors that contribute to the ordering of a UA and to decipher if LOS was more impacted in patients who were discharged vs. admitted to the hospital.

Methods

Retrospective chart review was conducted of patients who presented to our ED in April 2016 during 12 consecutive days. Data were abstracted onto a data collection sheet with the abstractor blinded to study hypotheses. Variables included whether a UA was ordered, times of UA order and result, who ordered the UA (mid-level provider [MLP] vs. physician), whether the UA was cancelled, whether the UA result influenced clinical decision-making (based on the medical decision-making section of the physician chart) or disposition decision, LOS, age, and gender. Descriptive statistics and multivariable regression analysis were used to analyze relationships between the variables collected and their influence on LOS.

Results

The overall median LOS was 157 minutes, with an interquartile range (IQR) of 81 to 246 minutes. For discharged patients, it was 142 minutes, with an IQR of 46 to 236 minutes. For admitted patients, it was 177 minutes, with an IQR of 118 to 260 minutes. Amongst admitted patients, multivariable regression analysis demonstrated that the following factor was associated with increased LOS: being seen first by the provider-in-triage (PIT) then physician in main ED (p < 0.0001). Amongst discharged patients, multivariable regression analysis demonstrated that the following factors were associated with increased LOS: being seen first by the PIT then physician in main ED (p = 0.0296), being seen by MLP only (p < 0.0001), having a UA ordered (p = 0.0005), being seen on weekend (p = 0.0166), and being an older patient (p = 0.0475). The UA was cancelled in 9% of our patients, and in 60% of cases, these UAs were ordered by the PIT. Patient disposition decision was made prior to UA resulting in 60 cases (25%). The UA was used in clinical decision-making in 118 cases (66%). The following predictor factors were associated via univariate analysis with using a UA for decision-making: being female (p = 0.0050, 95% CI: 0.0068–0.378), being an older patient (p < 0.0001, 95% CI: -0.010 to -0.004), being first seen by the PIT and then a physician (p = 0.0486, 95% CI: 0.0048–0.1555), and discharged patients (p < 0.0001, 95% CI: -0.6749 to -0.4487).

Conclusion

Our results suggest that having a UA ordered increased ED LOS, especially in patients who are ultimately discharged. In our ED, routine UAs are ordered more often by MLPs than physicians. A routine UA may not impact clinical decision-making up to 33% of the time, nor alter disposition decision one out of four times. Given that 9% have the test eventually cancelled, one should reconsider the utility in ordering routine UAs in ED patients, as they increase LOS and place an additional burden on the patient and the ED personnel.

Use of a midstream clean catch mobile application did not lower urine contamination rates in an ED

OBJECTIVES

Urine microscopy is a common test performed in emergency departments (EDs). Urine specimens can easily become contaminated by different factors, including the collection method. The midstream clean-catch (MSCC) collection technique is commonly used to reduce urine contamination. The urine culture contamination rate from specimens collected in our ED is 30%. We developed an instructional application (app) to show ED patients how to provide a MSCC urine sample. We hypothesized that ED patients who viewed our instructional app would have significantly lower urine contamination rates compared to patients who did not.

METHODS

We prospectively enrolled 257 subjects with a urinalysis and/or urine culture test ordered in the ED and asked them to watch our MSCC instructional app. After prospective enrollment was complete, we retrospectively matched each enrolled subject to an ED patient who did not watch the instructional app. Controls were matched to cases based on gender, type of urine specimen provided, ED visit date and shift. Urinalysis and urine culture contamination results were compared between the matched pairs using McNemar's test.

RESULTS

The overall urine culture contamination rate of the 514 subjects was 38%. The majority of the matched pairs had a urinalysis (63%) or urinalysis plus urine culture (35%) test done. There were no significant differences in our urine contamination rates between the matched pairs overall or when stratified by gender, by prior knowledge of the clean catch process or by type of urine specimen.

CONCLUSION

We did not see a lower contamination rate for patients who viewed our instructional app compared to patients who did not. It is possible that MSCC is not effective for decreasing urine specimen contamination.

Impact of eliminating reflex urine cultures on performed urine cultures and antibiotic use

Inappropriate treatment of asymptomatic bacteriuria is often the result of unnecessary urinalyses and urine cultures. This study aimed to determine the impact of stopping the practice of reflex urine cultures. Our study demonstrated that stopping urine reflex cultures decreased the number of urine cultures performed and there was a trend toward a decrease in antibiotic use.

Urinary nitrite/nitrate ratio measured by isotope-dilution LC-MS/MS as a tool to screen for urinary tract infections

Urinary tract infections (UTIs) are the most common type of nosocomial infection. Traditionally, the presence of white blood cells and microorganisms in the urine provides objective evidence for UTI diagnosis. Here, we describe the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) to measure the nitrite and nitrate levels in urine and investigate the potential of this method for UTI diagnosis. LC-MS/MS analysis was performed in positive electrospray ionization mode. After adding (15)N-labeled internal standards and derivatizing with 2,3-diaminonaphthalene (DAN), the urinary nitrite content was directly analyzed by LC-MS/MS, whereas the urinary nitrate was first reduced to nitrite before derivatization and LC-MS/MS analysis. The derivatization of nitrite and enzymatic reduction of nitrate were optimized. This method was then applied to 241 healthy subjects and 73 UTI patients. Optimization tests revealed that 1 mL of crude urine required at least 6.25 μmol of DAN to completely derivatize nitrite and 2.5 U of nitrate reductase to completely reduce nitrate to nitrite. Urinary analysis showed that the urinary concentration of nitrite and the nitrite/nitrate ratio were higher in UTI patients than in healthy subjects. Compared with the dipstick-based urinary nitrite test and using LC-MS/MS to determine the nitrite concentration (sensitivity: 23-25%), the nitrite/nitrate ratio was significantly more sensitive (95%) and exhibited a satisfactory specificity (91%) in the screening of UTIs. Taken together, the nitrite/nitrate ratio, which reflects the reducing ability of pathogenic bacteria, could be a better method for the diagnosis of UTIs that is not subject to variations in urine specimen quality.

Point-Counterpoint: Reflex Cultures Reduce Laboratory Workload and Improve Antimicrobial Stewardship in Patients Suspected of Having Urinary Tract Infections

Urinary tract infections (UTIs) are frequent and lead to a large number of clinical encounters. A common management strategy for patients suspected of having a urinary tract infection is to test for pyuria and bacteria by urine analysis (UA) of midstream urine, with initiation of antibiotic therapy and urine culture if one or both tests are positive. Although this practice was first used in an outpatient setting with midstream urine samples, some institutions allow its use in the management of catheterized patients. The ideas behind the reflex urine culture are to limit laboratory workload by not performing culture on negative specimens and to improve antimicrobial stewardship by not giving antimicrobials to patients with negative UA results. The questions are, first, whether reflex urine culture reduces workloads significantly and, second, whether it improves antimicrobial stewardship in the era of increasing numbers of urinary tract infections due to extensively drug-resistant Gram-negative bacilli. Romney Humphries from UCLA supports the idea that reflex urine cultures are of value and describes what reflex parameters are most useful, while Jennifer Dien Bard of Children's Hospital Los Angeles discusses their limitations.

Antimicrobial Stewardship in the Emergency Department

The literature contains robust evidence on the positive impact of antimicrobial stewardship programs (ASP) in the inpatient setting. With national policies shifting toward provisions of quality health care, the impetus to expand ASP services becomes an important strategy for institutions. However data on stewardship initiatives in other settings are less characterized. For organizations with an established ASP team, it is rational to consider expanding these services to the emergency department (ED). The ED serves as an interface between the inpatient and community settings. It is often the first place where patients present for medical care, including for common infections. Challenges inherent to the fast-paced nature of the environment must be recognized for successful ASP implementation in the ED. Based on the current literature, a combination of strategies for initiating ASP services in the ED will be described. Furthermore, common scenarios and management approaches are proposed for respiratory tract, skin and soft tissue, and urinary tract infections. Expansion of ASP services across the health care continuum may improve patient outcomes with a potential associated decrease in health care costs while preventing adverse effects including the development of antibiotic resistance.

Bacteruria and Urinary Tract Infections in the Elderly

Both urinary tract infection (UTI) and asymptomatic bacteriuria (ASB) are common problems among elderly adults and represent a significant health care burden. Despite their frequency, differentiating between ASB and true UTI remains controversial among health care providers. Several challenges exist in the evaluation of urinary symptoms in the elderly patient. Symptoms of UTI are variable; problems are encountered in the collection, testing, and interpretation of urine specimens; and results of urinalysis are often misinterpreted and mishandled. Multiple studies have shown no morbidity or mortality benefit to antibiotic therapy in either community or long-term care facility residents with ASB.