Background: Candida auris is an emerging, healthcare?associated pathogen that persists on skin and in the environment. Early identification of colonized patients is central to interrupting transmission, but the optimal screening cadence in cluster settings is uncertain. We evaluated whether intensifying targeted screening and transitioning to in?house PCR were associated with changes in clinical cases at a large quaternary academic medical center. Methods: We conducted a retrospective study from November 2022 through March 2024 in hospital units experiencing C. auris clusters. Screening frequency was escalated in phases—from biweekly to weekly—and later transitioned to in?house PCR to enable faster turnaround and earlier implementation of infection?prevention actions (e.g., isolation/cohorting and enhanced environmental cleaning) per institutional protocol. The primary outcome was the monthly number of new clinical C. auris cases, defined as non?screening clinical isolates with urine and sputum excluded. The secondary outcome was colonization detected by screening PCR or by urine or sputum cultures. Monthly outcomes were monitored with statistical process control (control charts centered on phase?specific means), and effects across phases were summarized as percentage changes versus baseline. Results: Thirty?eight clinical cases were identified; median age was 55 years (IQR 44–65), and 66% were male. Most clinical isolates originated from blood and wound/tissue sources. Fifteen cases (39%) had a prior positive surveillance test; the median time from first positive screen to subsequent clinical isolate was 27 days (IQR 17–120). Monthly clinical cases decreased from 2.5 during biweekly screening to 2.0 with weekly screening (?20%) and to 1.7 after adoption of in?house PCR (additional ?15%; -32% overall vs baseline) (Figure 1). Colonization detections increased when screening frequency changed from biweekly to weekly (5.3 to 13.8 per month; +160%) and then declined after in?house PCR (to 10.2 per month; -26%). These patterns were concordant with control?chart signals at the phase changes. Conclusions: Targeted, more frequent screening coupled with rapid in?house PCR was associated with fewer clinical C. auris cases and with higher detection of colonization, consistent with earlier identification and response. Because the clinical?case metric is less sensitive to testing intensity and speciation practices than colonization counts, it may better capture the impact of hospital interventions on transmission. Findings are limited by the single?center, retrospective design, potential confounding from concurrent infection?prevention measures, and use of monthly counts rather than rates; nonetheless, the phased approach provides actionable evidence to guide surveillance strategies during C. auris clusters.
Background: Older adults (≥65 years) commonly receive antibiotics in emergency departments (ED), where adherence to prescribing guidelines is inconsistent. The extent to which neighborhood disadvantage causally influences these prescribing patterns is unclear. We aimed to estimate the causal effect of community deprivation and vulnerability on guideline-concordant antibiotic selection and to disentangle the relative contributions of overuse and underuse. Methods: We analyzed 1,318,281 ED encounters for 790,562 adults aged ≥ 65 years seen at 119 sites across 15 states (2015–2024). The primary outcome was guideline concordance based on IDSA criteria. Secondary outcomes were overuse and underuse, defined using a three-tier diagnosis framework (tier 1 = antibiotics indicated, tier 2 = sometimes indicated, tier 3 = not indicated). Exposures were census-tract Social Vulnerability Index (SVI) and Social Deprivation Index (SDI). To mitigate confounding and reverse causality, we applied two-stage least squares instrumental-variable models using the maximum state Earned Income Tax Credit as the instrument, adjusting for patient, facility, state, and month-year covariates with patient-clustered robust standard errors. We additionally examined key SVI/SDI components and regional patterns in concordance. Results: Overall concordance was 83.2%; non-concordance comprised 9.5% overuse and 7.2% underuse. Concordance improved from 78.4% (2015) to 83.8% (2024), driven by declining underuse (16.2 to 5.4%) despite rising overuse (5.4 to 10.8%). Antibiotics were given in 80.8% of tier 1, 28.1% of tier 2, and 15.9% of tier 3 encounters. COVID-19 diagnoses accounted for 20.1% of overuse, and urinary-tract infection codes for 33.6% of underuse. The instrument was strong (first-stage F = 348 for SVI; 413 for SDI). In IV models, each 10-point increase in SVI corresponded to a 6.37-point lower concordance (SE 0.69; p < 0.001, Table 1); each 10-point SDI increase, 1.84-point lower (SE 0.20; p < 0.001). Associations were stronger for underuse than for overuse. Lower concordance was linked to longer travel time, higher tract non-employment, household crowding, and lack of vehicle access. Regions of high deprivation and lower concordance clustered predominantly in the South, whereas higher-concordance areas were concentrated in the Midwest (Figure 1). Conclusions: Community disadvantage was associated with lower guideline-concordant antibiotic prescribing for older adults, mainly through increased underuse and modest reductions in overuse. Stewardship programs should monitor both phenomena separately and target high-deprivation areas with enhanced diagnostics, follow-up, and locally tailored implementation to improve equity.
Background: Social deprivation may affect both infection severity and the quality of antibiotic prescribing, but its influence on downstream outcomes and the role of stewardship processes in this pathway remain uncertain. Methods: We conducted a retrospective cohort study of 1,365,957 emergency department (ED) encounters among older adults across multiple U.S. hospitals, 2013–2022. We assessed the impact of community social deprivation on clinical outcomes and identified mediation through antibiotic prescribing (guideline-concordant empiric use). Social deprivation was quantified using a z-scored Social Deprivation Index (SDI). Outcomes were log-transformed length of stay (LOS), 30-day ED revisit, 30-day mortality, 30-day C. difficile infection, and DOOR (Desirability of Outcome Ranking; 1=alive with LOS at or below the median and no 30-day events, 2=alive with LOS above the median and no events, 3=30-day ED revisit, 4<=i>C. difficile infection, 5=death). We fitted multivariable ordinary least squares models with state- and month-fixed effects and clustered standard errors, controlling for demographics, comorbidities, clinical severity, travel time, hospital characteristics, and rurality. We applied regression-based mediation analysis to partition the SDI–outcome relationship into direct effects and indirect effects mediated by prescribing concordance. Secondary models substituted antibiotic overuse or underuse for concordance. Results: Concordant prescribing occurred in 83% of encounters; overuse and underuse occurred in 9.5% and 7.4%, respectively. Higher SDI was associated with slightly worse outcomes: each 1-SD increase corresponded to modestly longer LOS, higher risk of 30-day ED revisit and mortality, and worse DOOR scores, with minimal association with C. difficile infection (Figure 1). Concordance was strongly associated with better outcomes, including shorter LOS, fewer ED revisits, lower mortality, and lower DOOR scores. Mediation analyses (Figure 2) indicated that concordance explained about 11% of the SDI–LOS association and <5% of the associations with ED revisit, mortality, and DOOR. In secondary models (Figure 3), overuse was consistently associated with worse outcomes—longer LOS, higher mortality, and higher DOOR scores—independent of SDI. Underuse showed inverse associations with LOS and DOOR but only tiny, clinically negligible increases in ED revisit and mortality, patterns likely reflecting residual confounding and selection of lower-acuity patients. Conclusion: We found that social deprivation was associated with worse health outcomes, with antibiotic concordance serving as a partial pathway linking deprivation to harm. Stewardship efforts that improve concordance and curb overuse—particularly in socially deprived communities—may help reduce outcome disparities without encouraging under-treatment.
Background: Asymptomatic bacteriuria (ASB) is common in older adults; however, its treatment in this population is not beneficial and can be harmful. We developed an intervention to update the indications on a urinalysis and urine culture order set according to recent Infectious Diseases Society of America (IDSA) guidelines recommending against testing and treatment for bacteriuria in older adults with altered mental status (AMS) or falls. Methods: This retrospective quasi-experimental study included adult patients > 65 years who presented to an Emergency Department (ED) in Southeast Texas from July 2018 to February 2024. The intervention, implemented in June 2020, included a change in the urinalysis (UA) with reflex to urine culture order set that replaced “AMS” as an indication for UA with “AMS and fever or leukocytosis” and provider education. The study’s primary outcome was whether urine studies were obtained within 24 hours of presentation to the ED. Secondary outcomes were antibiotic days of therapy (DOT) for suspected UTI, length of stay (LOS), and 30-day hospital readmission. The difference in differences (DID) technique was used to assess the impact of the intervention on older adults who presented with AMS or a fall (cases) compared to those with other chief complaints (controls). Outcomes were evaluated using multiple regression models (logistic for urinary studies ordered and readmission, linear for log LOS, and zero-inflated negative binomials for DOT) adjusted for patient demographics and comorbidities. Results: The study included 31,626 patients. Almost a third of older adult patients who presented to the ED with a fall or AMS (31.5%) received urinary testing, and 5.9% received antibiotics. 20.2% of control patients received urinary testing in the ED, and 6.3% received antibiotics. After adjusting for confounders, the intervention did not impact the percentage of tests ordered [(DID OR 1.14, 95% CI 0.93 – 1.40), (Figure 1)]. The incident rate ratio (IRR) of not receiving antibiotics was similar after the intervention (IRR 0.78, 95% CI 0.54 – 1.13), while the baseline number of antibiotics a patient received increased (IRR 1.54, 95% CI 1.05 – 2.27). Conclusions: Modifying UA indications on the urinalysis order set did not reduce testing or treatment for bacteriuria in older adults presenting with AMS or a fall. Longer-term or repetitive educational interventions could be an effective way to improve long-term stewardship outcomes in this population, especially for providers with less exposure to guidelines. Further discussion and investigation are needed.
Background: While broad gastrointestinal (GI) multiplex polymerase chain reaction (PCR) panels can test for various bacterial, viral, and parasitic pathogens, their overuse may yield a high financial burden on hospital systems without clear clinical relevance of all covered organisms. This study aims to assess whether a multifaceted quality improvement intervention directing clinicians to a more limited panel and requiring several restriction criteria would reduce direct hospital costs for patients with suspected infectious diarrhea. Methods: Our quasi-experimental study included patients from a quaternary academic medical center in Texas. In the pre-intervention period (March 2024-June 2024), the Biofire® FilmArray® Gastrointestinal Panel (BioFire Diagnostics, Salt Lake City, UT) was the preferred test for patients presenting with suspected infectious diarrhea and had minimal ordering restrictions (Figure 1). In the post-intervention period (August 2024- November 2024), a second narrower panel (GI Common Pathogen PCR panel) was introduced as the preferred test with some restrictions, while the Biofire® FilmArray® GI Panel was only available to severely immunosuppressed patients and required Infectious Diseases consultation. The restriction criteria were built in the Epic electronic health system (Epic System Corporation, Verona, WI). Information on the intervention was distributed through email memorandums and an internal secure clinical messaging platform. Count control charts were used to visualize the number of FilmArray® GI Panels conducted, while individual control charts were used for the direct laboratory costs of both GI panels. Results: 893 patients had suspected infectious diarrhea in the study period (451 pre-intervention, 442 post-intervention). The average number of weekly FilmArray® GI Panel tests performed dropped from 24.8 to 1.9 (Figure 2), and an average of 21.9 GI Common Panel tests per week were performed in the post-intervention period. The average weekly testing cost decreased from $3,418.10 to $940.40 after the intervention (Figure 3). The two control charts demonstrated the presence of special cause variation for both outcomes (weekly FilmArray® GI Panel tests and combined costs), indicating a change after the intervention. Conclusion: Although the total number of tests did not change after adjusting the restriction criteria, this intervention significantly reduced the direct laboratory costs of the GI Panels after guiding clinicians to a more economical test (GI Common Panel), with an estimated annual savings of $128,840. This study provides a diagnostic stewardship opportunity for cost reduction in healthcare systems. Future evaluation will analyze its impact on antimicrobial utilization and infection control metrics.
Background: Several studies have shown an association between deprivation and excessive antibiotic use in the US. However, these studies were limited by their geographic design, making them unable to assess a causative relationship. This study analyzed the impact of socioeconomic deprivation on antibiotic days supplied among older Medicare Part D beneficiaries in the US using an instrument variable (IV) approach. Method: This study utilized the Medicare Part D and the Social Deprivation Index (SDI) repositories. The maximum Earned Income Tax Credit was chosen as an IV to consider the reverse causality of the SDI values. Spatial dependence between predicted SDI and study outcome (log antibiotic days supplied per 100 beneficiaries) was evaluated by global Moran’s I analysis and cluster mapping. Linear regression models were performed to assess the impact of predicted SDI or its components (poverty, single parent, low education, no car, renter-occupied, crowding, and non-employment) on the study outcome. The study adjusted for the following confounders: prescriber gender, specialty, graduate school rank, teaching location, metropolitan area, US state, and beneficiary characteristics (demographics, risk scores, and dual public insurance). Results: A total of 438,431 providers were included. There was no spatial dependence between the predicted SDI and study outcome (I = 0.007, P = 0.0656, Figure). Higher predicted SDI values resulted in higher antibiotic days supplied (log) per 100 beneficiaries (estimate 0.58, SE 0.16, P) Conclusion: This study showed a causative relationship between SDI and antibiotic days supplied. It highlights opportunities for public health in the US to explore gaps in antimicrobial stewardship. More studies are needed to investigate the knowledge and attitudes of patients and providers and potential barriers to access that might impact antibiotic prescription in older patients.
Background: The overuse of antimicrobials contributes to the development of antibiotic resistance, the development of Clostridioides difficile infections, and increased patient morbidity and mortality. The impact of U.S. News medical school ranking on provider antimicrobial prescription is largely unknown. Our study aimed to assess whether there was a relationship between graduating from higher-ranked medical schools and the rate of prescribing antibiotics among Medicare Part D providers in the US. Methods: The ecological study obtained data from the Medicare Part D Prescribers (FY2013-2021) and the Doctor and Clinicians National repositories. The study’s main outcome was antibiotic days supplied per 100 beneficiaries. Secondary outcomes included antibiotic claims per 100 beneficiaries, days per claim, and antibiotic cost per 100 beneficiaries. A regression model was fitted to assess the relationship between provider medical school ranking and study outcomes. The study controlled for several state, provider, and patient variables. Results: A total of 197,540 providers were included (Table 1). No association was found between the medical school ranking and the rate of antibiotics days supplied per 100 beneficiaries (Table 2, Figure). Instead, the type of provider is associated with the prescription rates. Hospitalists and Emergency Medicine providers had fewer days supplied per 100 beneficiaries than Family Medicine providers. In contrast, students, more experienced providers (>20 years since medical school graduation), and females had more days supplied per 100 beneficiaries. Higher-ranking medical schools [1, 35], EM providers and hospitalists (vs. FM), and academic locations had lower claim rates per 100 beneficiaries, while students and experienced providers had higher claims. Days per claim were higher among providers from higher-ranked medical schools, more experienced providers, students, and academic locations, whereas they were lower among males, EM Providers, and Hospitalists. Costs per 100 beneficiaries were higher among students, academic locations, IM providers, and males; however, it was lower among EM and hospitalists. Conclusion: Our study showed no impact of medical school ranking on the overall rate of outpatient antibiotic prescriptions among Medicare Part D providers. While the claim rate per 100 beneficiaries was lower among providers from higher-rank medical schools compared to other providers, claims were prescribed longer, leading to similar days supplied and costs compared with other providers. This highlights the need for robust outpatient stewardship interventions and incorporating an outcome-based approach to antibiotic stewardship curricula in medical and mid-level provider schools.
