Bacterial resistance is known to diminish the effectiveness of antibiotics for treatment of urinary tract infections. Review of recent healthcare and antibiotic exposures, as well as prior culture results is recommended to aid in selection of empirical treatment. However, the optimal approach for assessing these data is unclear. We utilized data from the Veterans Health Administration to evaluate relationships between culture and treatment history and the subsequent probability of antibiotic-resistant bacteria identified in urine cultures to further guide clinicians in understanding these risk factors.

Using the XGBoost algorithm, a retrospective cohort of outpatients with urine culture results and antibiotic prescriptions from 2017 to 2022 was used to develop models for predicting antibiotic resistance for three classes of antibiotics: cephalosporins, fluoroquinolones, and trimethoprim/sulfamethoxazole (TMP/SMX) obtained from urine cultures. Model performance was assessed using Area Under the Receiver Operating Characteristic curve (AUC) and Precision-Recall AUC (PRAUC)

There were 392,647 prior urine cultures identified in 214,656 patients. A history of bacterial resistance to the specific treatment was the most important predictor of subsequent resistance for positive cultures, followed by a history of specific antibiotic exposure. The models performed better than previously established risk factors alone, especially for fluoroquinolone resistance, with an AUC of .84 and PRAUC of .70. Notably, the models’ performance improved markedly (AUC = .90, PRAUC = .87) when applied to cultures from patients with a known history of resistance to any of the antibiotic classes.

These predictive models demonstrate potential in guiding antibiotic prescription and improving infection management.

To examine the perspectives of caregivers that are not part of the antibiotic stewardship program (ASP) leadership team (eg, physicians, nurses, and clinical pharmacists), but who interact with ASPs in their role as frontline healthcare workers.

Qualitative semistructured interviews.

The study was conducted in 2 large national healthcare systems including 7 hospitals in the Veterans’ Health Administration and 4 hospitals in Intermountain Healthcare.

We interviewed 157 participants. The current analysis includes 123 nonsteward clinicians: 47 physicians, 26 pharmacists, 29 nurses, and 21 hospital leaders.

Interviewers utilized a semistructured interview guide based on the Consolidated Framework for Implementation Research (CFIR), which was tailored to the participant’s role in the hospital as it related to ASPs. Qualitative analysis was conducted using a codebook based on the CFIR.

We identified 4 primary perspectives regarding ASPs. (1) Non-ASP pharmacists considered antibiotic stewardship activities to be a high priority despite the added burden to work duties: (2) Nurses acknowledged limited understanding of ASP activities or involvement with these programs; (3) Physicians criticized ASPs for their restrictions on clinical autonomy and questioned the ability of antibiotic stewards to make recommendations without the full clinical picture; And (4) hospital leaders expressed support for ASPs and recognized the unique challenges faced by non-ASP clinical staff.

Further understanding these differing perspectives of ASP implementation will inform possible ways to improve ASP implementation across clinical roles.

To conduct a contemporary detailed assessment of outpatient antibiotic prescribing and outcomes for positive urine cultures in a mixed-sex cohort.

Multicenter retrospective cohort review.

The study was conducted using data from 31 Veterans’ Affairs medical centers.

Outpatient adults with positive urine cultures.

From 2016 to 2019, data were extracted through a nationwide database and manual chart review. Positive urine cultures were reviewed at the chart, clinician, and aggregate levels. Cases were classified as cystitis, pyelonephritis, or asymptomatic bacteriuria (ASB) based upon documented signs and symptoms. Preferred therapy definitions were applied for subdiagnoses: ASB (no antibiotics), cystitis (trimethoprim-sulfamethoxazole, nitrofurantoin, β-lactams), and pyelonephritis (trimethoprim-sulfamethoxazole, fluoroquinolone). Outcomes included 30-day clinical failure or hospitalization. Odds ratios for outcomes between treatments were estimated using logistic regression.

Of 3,255 cases reviewed, ASB was identified in 1,628 cases (50%), cystitis was identified in 1,156 cases (36%), and pyelonephritis was identified in 471 cases (15%). Of all 2,831 cases, 1,298 (46%) received preferred therapy selection and duration for cases where it could be defined. The most common antibiotic class prescribed was a fluoroquinolone (34%). Patients prescribed preferred therapy had lower odds of clinical failure: preferred (8%) versus nonpreferred (10%) (unadjusted OR, 0.74; 95% confidence interval [CI], 0.58–0.95; P = .018). They also had lower odds of 30-day hospitalization: preferred therapy (3%) versus nonpreferred therapy (5%) (unadjusted OR, 0.55; 95% CI, 0.37–0.81; P = .002). Odds of clinical treatment failure or hospitalization was higher for β-lactams relative to ciprofloxacin (unadjusted OR, 1.89; 95% CI, 1.23–2.90; P = .002).

Clinicians prescribed preferred therapy 46% of the time. Those prescribed preferred therapy had lower odds of clinical failure and of being hospitalized.

To determine whether a clinician-directed acute respiratory tract infection (ARI) intervention was associated with improved antibiotic prescribing and patient outcomes across a large US healthcare system.

Multicenter retrospective quasi-experimental analysis of outpatient visits with a diagnosis of uncomplicated ARI over a 7-year period.

Outpatients with ARI diagnoses: sinusitis, pharyngitis, bronchitis, and unspecified upper respiratory tract infection (URI-NOS). Outpatients with concurrent infection or select comorbid conditions were excluded.

Audit and feedback with peer comparison of antibiotic prescribing rates and academic detailing of clinicians with frequent ARI visits. Antimicrobial stewards and academic detailing personnel delivered the intervention; facility and clinician participation were voluntary.

We calculated the probability to receive antibiotics for an ARI before and after implementation. Secondary outcomes included probability for a return clinic visits or infection-related hospitalization, before and after implementation. Intervention effects were assessed with logistic generalized estimating equation models. Facility participation was tracked, and results were stratified by quartile of facility intervention intensity.

We reviewed 1,003,509 and 323,023 uncomplicated ARI visits before and after the implementation of the intervention, respectively. The probability to receive antibiotics for ARI decreased after implementation (odds ratio [OR], 0.82; 95% confidence interval [CI], 0.78–0.86). Facilities with the highest quartile of intervention intensity demonstrated larger reductions in antibiotic prescribing (OR, 0.69; 95% CI, 0.59–0.80) compared to nonparticipating facilities (OR, 0.89; 95% CI, 0.73–1.09). Return visits (OR, 1.00; 95% CI, 0.94–1.07) and infection-related hospitalizations (OR, 1.21; 95% CI, 0.92–1.59) were not different before and after implementation within facilities that performed intensive implementation.

Implementation of a nationwide ARI management intervention (ie, audit and feedback with academic detailing) was associated with improved ARI management in an intervention intensity–dependent manner. No impact on ARI-related clinical outcomes was observed.

To examine how individual steward characteristics (eg, steward role, sex, and specialized training) are associated with their views of antimicrobial stewardship program (ASP) implementation at their institution.

Descriptive survey from a mixed-methods study.

Two large national healthcare systems; the Veterans’ Health Administration (VA) (n = 134 hospitals) and Intermountain Healthcare (IHC; n = 20 hospitals).

We sent the survey to 329 antibiotic stewards serving in 154 hospitals; 152 were physicians and 177 were pharmacists. In total, 118 pharmacists and 64 physicians from 126 hospitals responded.

The survey was grounded in constructs of the Consolidated Framework for Implementation Research, and it assessed stewards’ views on the development and implementation of antibiotic stewardship programs (ASPs) at their institutions We then examined differences in stewards’ views by demographic factors.

Regardless of individual factors, stewards agreed that the ASP added value to their institution and was advantageous to patient care. Stewards also reported high levels of collegiality and self-efficacy. Stewards who had specialized training or those volunteered for the role were less likely to think that the ASP was implemented due to a mandate. Similarly volunteers and those with specialized training felt that they had authority in the antibiotic decisions made in their facility.

Given the importance of ASPs, it may be beneficial for healthcare institutions to recruit and train individuals with a true interest in stewardship.

Acute respiratory tract infections (ARIs) are commonly diagnosed and major drivers of antibiotic prescribing. Clinician-focused interventions can reduce unnecessary antibiotic prescribing for ARIs. We elicited clinician feedback to design sustainable interventions to improve ARI management by understanding the mental framework of clinicians surrounding antibiotic prescribing within Veterans’ Health Administration clinics.

We conducted one-on-one interviews with clinicians (n = 20) from clinics targeted for intervention at 5 facilities. The theory of planned behavior guided interview questions. Interviews were audio recorded and transcribed for qualitative analysis. An iterative coding approach identified 6 themes.

Emergent themes: (1) barriers to appropriate prescribing are multifactorial and include challenges of behavior change; (2) antibiotic prescribing decisions are perceived as autonomous yet, diagnostic uncertainty and perceptions of patient demand can make prescribing decisions difficult; (3) clinicians perceive variation in peer prescribing practices and influences; (4) clinician-focused interventions are valuable if delivered with sensitivity; (5) communication strategies for educating patients are preferred to a shared decisions process; and (6) team standardization of practice and communication are key to facilitate appropriate prescribing. Clinicians perceived audit-and-feedback with peer comparison, academic detailing, and enhanced patient communication strategies as viable approaches to improving appropriate prescribing.

Implementation strategies that enable clinicians to overcome diagnostic uncertainty, perceived patient demand, and improve patient education are desired. Implementation strategies were welcomed, and some were more readily accepted (eg, audit feedback) than others (eg, shared decision making). Implementation strategies should address clinicians’ perceptions of antibiotic prescribing practices and should enhance their patient communication skills.

To detail the activities of the Veterans Health Administration (VHA) Antimicrobial Stewardship Initiative and evaluate outcomes of the program.

Observational analysis.

The VHA is a large integrated healthcare system serving approximately 6 million individuals annually at more than 140 medical facilities.

Utilization of nationally developed resources, proportional distribution of antibiotics, changes in stewardship practices and patient safety measures were reported. In addition, inpatient antimicrobial use was evaluated before and after implementation of national stewardship activities.

Nationally developed stewardship resources were well utilized, and many stewardship practices significantly increased, including development of written stewardship policies at 92% of facilities by 2015 (P<.05). While the proportional distribution of antibiotics did not change, inpatient antibiotic use significantly decreased after VHA Antimicrobial Stewardship Initiative activities began (P<.0001). A 12% decrease in antibiotic use was noted overall. The VHA has also noted significantly declining use of antimicrobials prescribed for resistant Gram-negative organisms, including carbapenems, as well as declining hospital readmission and mortality rates. Concurrently, the VHA reported decreasing rates of Clostridium difficile infection.

The VHA National Antimicrobial Stewardship Initiative includes continuing education, disease-specific guidelines, and development of example policies in addition to other highly utilized resources. While no specific ideal level of antimicrobial utilization has been established, the VHA has shown that improving antimicrobial usage in a large healthcare system may be achieved through national guidance and resources with local implementation of antimicrobial stewardship programs.

Infect Control Hosp Epidemiol 2017;38:513–520

Antimicrobial stewardship programs (ASPs) are variably implemented.

To characterize variations of antimicrobial stewardship structure and practices across all inpatient Veterans Affairs facilities in 2012 and correlate key characteristics with antimicrobial usage.

A web-based survey regarding stewardship activities was administered to each facility’s designated contact. Bivariate associations between facility characteristics and inpatient antimicrobial use during 2012 were determined.

Total of 130 Veterans Affairs facilities with inpatient services.

Of 130 responding facilities, 29 (22%) had a formal policy establishing an ASP, and 12 (9%) had an approved ASP business plan. Antimicrobial stewardship teams were present in 49 facilities (38%); 34 teams included a clinical pharmacist with formal infectious diseases (ID) training. Stewardship activities varied across facilities, including development of yearly antibiograms (122 [94%]), formulary restrictions (120 [92%]), stop orders for antimicrobial duration (98 [75%]), and written clinical pathways for specific conditions (96 [74%]). Decreased antimicrobial usage was associated with having at least 1 full-time ID physician (P=.03), an ID fellowship program (P=.003), and a clinical pharmacist with formal ID training (P=.006) as well as frequency of systematic patient-level reviews of antimicrobial use (P=.01) and having a policy to address antimicrobial use in the context of Clostridium difficile infection (P=.01). Stop orders for antimicrobial duration were associated with increased use (P=.03).

ASP-related activities varied considerably. Decreased antibiotic use appeared related to ID presence and certain select practices. Further statistical assessments may help optimize antimicrobial practices.

Infect Control Hosp Epidemiol 2016;37:647–654

Society for Health Care Epidemiology guidelines recommend decreasing the use of fluoroquinolone antibiotics in institutions where methicillin-resistant Staphylococcus aureus (MRSA) is endemic. We evaluated whether an intervention to limit fluoroquinolone use was associated with a lower rate of nosocomial MRSA infection and summarized changes in antibiotic use, changes in other variables potentially correlated with a lower rate of MRSA infection, and rates of nosocomial infections due to other pathogens.

Single-center quasi-experimental design. A time series of nosocomial MRSA infections was measured at monthly intervals from July 2001 through June of 2004; there were 80 MRSA infections recorded. Segmented regression analysis (ie, quasi-Poisson generalized linear models) was used to evaluate variables possibly associated with the nosocomial MRSA infection rate.

An 87-bed Veterans Affairs teaching hospital with an extended-care facility.

A physician-directed computer-generated intervention designed to limit the use of fluoroquinolone antibiotics was initiated, and institutional changes in antibiotic use and nosocomial MRSA infection rates were tracked.

After the intervention, fluoroquinolone use decreased by approximately 34%, and levofloxacin use decreased by approximately 50%. Decreased fluoroquinolone use was offset by increased cephalosporin, piperacillin-tazobactam, and trimethoprim-sulfamethoxazole use. The nosocomial MRSA infection rate decreased from 1.37 to 0.63 episodes per 1,000 patient-days after the study intervention (P = .02). Coagulase-negative Staphylococcus and Enterococcus infection rates also decreased. However, the rate of infection with gram-negative organisms increased. The rate of MRSA infection was positively correlated with levofloxacin use (P = .01) and azithromycin use (P = .08), whereas it was negatively correlated with summer season (P = .05). In a subsequent model, the rate of MRSA infection was negatively correlated with the study intervention (P = .04).

Reduction in the institutional use of fluoroquinolones may be associated with a lower nosocomial MRSA infection rate.