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.

Staphylococcal scalded skin syndrome: Clinical features, ancillary testing, and patient management.

BACKGROUND/OBJECTIVES: The utility of ancillary testing in improving diagnostic precision or improving patient outcomes in staphylococcal scalded skin syndrome (SSSS) is unclear. Similarly, an optimal antibiotic regimen has yet to be established. Our goal was to describe clinical characteristics and ancillary work-up of SSSS, report bacterial resistance patterns, and examine patient outcomes under varying therapeutic strategies with the aim of developing an evidence-based management algorithm. METHODS: We performed a retrospective review of pediatric patients diagnosed with SSSS at Intermountain Healthcare facilities between 2010 and 2021. A Kruskal-Wallis rank sum test was used to assess median length of stay between different antibiotic regimens. RESULTS: Eighty-five cases were identified. The most common ancillary tests obtained were a complete blood count (88%), followed by chemistry analysis (80%). Blood cultures were collected in more patients (79%) compared to aerobic cultures (60%). No blood culture was positive for Staphylococcus aureus. All S. aureus isolates were methicillin-sensitive. Of those found resistant to clindamycin (36%), all demonstrated macrolide-induced clindamycin resistance. None were constitutively resistant to clindamycin. There was no statistical difference between antibiotic regimen and length of stay (p = .691). Receiving opiate medications was the only risk factor associated with prolonged hospitalization (p = .001). CONCLUSIONS: Ancillary testing does not improve diagnostic precision and can be reduced. Clindamycin does not improve patient outcomes, suggesting beta-lactams should be considered first line. Susceptibility patterns in our cohort demonstrate inducible clindamycin resistance as opposed to constitutive.

Vacant lot to community garden conversion and crime in Milwaukee: a difference-in-differences analysis.

BACKGROUND: Vacant lots generate the perception of neglect and are often opportunistic locations for crime. Evidence is building to suggest that greening vacant lots, especially through community engaged approaches, is associated with reductions in some types of crime. METHODS: Using a retrospective quasi-experimental approach, we compared the conversion of vacant lots into community gardens (n=53) with a group of matched control lots (n=159) to examine the effect of this intervention on police reported theft, violent and nuisance crime in Milwaukee, Wisconsin. Conversions often involved the addition of planter boxes to create a garden, and sometimes included benches, paths, works of art or other landscaping features. Public crime data were used to generate crime rates within 100 m and 250 m around each lot. RESULTS: Violent and nuisance crime rates are lower near treatment lots based on an unadjusted difference-in-differences analysis of means and two Poisson regression models. While no substantial effects were observed among theft crimes, the most consistent crime rate reductions were found among violent crime within 250 m, ranging between 3.7% and 6.4% across analyses. CONCLUSIONS: Despite the small number of interventions, community-driven vacant lot to garden conversions were associated with slight reductions in crime. Urban greening initiatives may be a promising strategy to reduce urban crime and warrant further study.

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.

Ownership of an artificial limb induced by electrical brain stimulation.

Replacing the function of a missing or paralyzed limb with a prosthetic device that acts and feels like one's own limb is a major goal in applied neuroscience. Recent studies in nonhuman primates have shown that motor control and sensory feedback can be achieved by connecting sensors in a robotic arm to electrodes implanted in the brain. However, it remains unknown whether electrical brain stimulation can be used to create a sense of ownership of an artificial limb. In this study on two human subjects, we show that ownership of an artificial hand can be induced via the electrical stimulation of the hand section of the somatosensory (SI) cortex in synchrony with touches applied to a rubber hand. Importantly, the illusion was not elicited when the electrical stimulation was delivered asynchronously or to a portion of the SI cortex representing a body part other than the hand, suggesting that multisensory integration according to basic spatial and temporal congruence rules is the underlying mechanism of the illusion. These findings show that the brain is capable of integrating "natural" visual input and direct cortical-somatosensory stimulation to create the multisensory perception that an artificial limb belongs to one's own body. Thus, they serve as a proof of concept that electrical brain stimulation can be used to "bypass" the peripheral nervous system to induce multisensory illusions and ownership of artificial body parts, which has important implications for patients who lack peripheral sensory input due to spinal cord or nerve lesions.

Culturally Adapted Mobile Technology Improves Environmental Health Literacy in Laurentian, Great Lakes Native Americans (Anishinaabeg).

The presence of persistent bioaccumulative toxics (PBT) in aquatic food chains complicates decision processes of people with a strong culture of fish consumption. This environmental contamination is especially problematic for Native American populations in the Laurentian Great Lakes region (Anishinaabeg). Pursuing the growing discipline of environmental health literacy (EHL) may help reduce toxic exposures, support healthy decision-making, and combat health deficits. Our goals for this research were first to improve environmental health literacy using novel technologies and second to help define environmental health literacy metrics that can be tracked over time, especially regarding culturally-contextualized health interests. We recently reported that a mobile app (Gigiigoo'inaan App) presenting personalized, culturally-contextualized fish consumption advice may improve EHL for the Anishinaabeg. Gigiigoo'inaan App safely supports desired fish consumption rates by putting local data into the hands of the Anishinaabeg. We conducted a pre-test post-test evaluation with 103 Aninishinaabe adults. Participants estimated their current fish meal consumption over a hypothetical month before exposure to the software and then planned their future consumption of fish meals in a month after using the mobile app. Significantly more monthly traditional fish meals on average (Median: 4 vs 2, p=0.0005) were selected when using the app versus pre-exposure to the app. Significantly more traditional grams of fish were also selected during use of the app relative to the pretest (Median: 680.39g vs 453.59g, p=0.0007). These increases were accompanied by widespread (97%) adherence to conventional advice that minimizes PBT exposure health effects (ATSDR minimum risk levels).

Electronic Transmutation (ET): Chemically Turning One Element into Another.

The concept of electronic transmutation (ET) depicts the processes that by acquiring an extra electron, an element with the atomic number Z begins to have properties that were known to only belong to its neighboring element with the atomic number Z+1. Based on ET, signature compounds and chemical bonds that are composed of certain elements can now be designed and formed by other electronically transmutated elements. This Minireview summarizes the recent developments and applications of ET on both the theoretical and experimental fronts. Examples on the ET of Group 13 elements into Group 14 elements, Group 14 elements into Group 15 elements, and Group 15 elements into Group 16 elements are discussed. Compounds and chemical bonding composed of carbon, silicon, germanium, phosphorous, oxygen and sulfur now have analogues using transmutated boron, aluminum, gallium, silicon, nitrogen, and phosphorous.

Mercury, Polychlorinated Biphenyls, Selenium, and Fatty Acids in Tribal Fish Harvests of the Upper Great Lakes.

The Chippewa Ottawa Resource Authority monitors fish contaminants in Anishinaabe (Great Lake Native American) tribal fisheries. This article updates previously reported trends in two persistent bioaccumulative toxic (PBT) substances that are the primary contributors to consumption advisory limits for these fish: methylmercury (MeHg) and polychlorinated biphenyls (PCBs). Also, we report, for the first time, an analysis of nutritional benefit bioindicators and metrics in these same Upper Great Lakes fish harvests: selenium (Se) and omega-3 fatty acids (PUFA-3s). A novel risk/benefit quantification originally presented by Ginsberg et al. is reported here to characterize the tradeoffs between fatty acid benefits and toxic MeHg health outcomes. We also report a Se benefit metric to characterize the possible protective value against MeHg neurotoxicity based on Ralston et al. Congruent with Anishinaabe cultural motivations to consume fish from their ancestral fisheries, nutritional content was high in locally caught fish and, in some respects, superior to farmed/store-bought fish. These Great Lakes fish still contained levels of PBTs that require careful education and guidance for consumers. However, the contaminant trends suggest that these fish need not be abandoned as important (both culturally and nutritionally) food sources for the Anishinaabe who harvested them.

Fatty Acids in Ten Species of Fish Commonly Consumed by the Anishinaabe of the Upper Great Lakes.

The Chippewa Ottawa Resource Authority (CORA) in Sault Ste. Marie, Michigan, has been monitoring contaminant concentrations in the fillet portions of fish from the 1836 treaty-ceded waters of lakes Superior, Huron, and Michigan since 1991. The goal is to provide up to date consumption advice for their CORA member tribes. For the first time since the program started, CORA has included fatty acid analysis in 2016 monitoring of fish in Lake Superior. Ten species were targeted by CORA based on 25 years of experience and regular discussions with Anishinaabe fish consumers. This paper reports these results and presents some preliminary discussion of the consequences for consumption advice for the CORA member tribes who inhabit the Great Lakes region. Six of the species were sampled from Lake Huron and Lake Superior and four were sampled from supermarkets. Wild caught fish are an important link to the culture of Great Lakes Native American tribes and important sources of food and omega-3 polyunsaturated fatty acids (PUFA N-3). While some PUFA N-3 data from the Great Lakes is available, this dataset provides an important supplement and is specific to the 1836-treaty ceded waters of CORA. This paper confirms the presence of PUFA N-3s in Great Lakes fish traditionally harvested by the CORA tribes.

Distributed cortical adaptation during learning of a brain-computer interface task.

The majority of subjects who attempt to learn control of a brain-computer interface (BCI) can do so with adequate training. Much like when one learns to type or ride a bicycle, BCI users report transitioning from a deliberate, cognitively focused mindset to near automatic control as training progresses. What are the neural correlates of this process of BCI skill acquisition? Seven subjects were implanted with electrocorticography (ECoG) electrodes and had multiple opportunities to practice a 1D BCI task. As subjects became proficient, strong initial task-related activation was followed by lessening of activation in prefrontal cortex, premotor cortex, and posterior parietal cortex, areas that have previously been implicated in the cognitive phase of motor sequence learning and abstract task learning. These results demonstrate that, although the use of a BCI only requires modulation of a local population of neurons, a distributed network of cortical areas is involved in the acquisition of BCI proficiency.

All-nitrogen analogue of ozone: Li3N3 species.

A theoretical study of ozone isoelectronic Li3N3 species has been performed. Ab initio electronic structure calculations prove the viability of the ozone-like Li3N3 molecule that might become synthesized. The predicted Li3N3 species with a novel N3(3-) molecular motif possess structural and chemical bonding features similar to that of O3 molecules and can thus be considered as an "all-nitrogen ozone".

Pharmacokinetic and pharmacodynamic optimisation of intravenous tobramycin dosing among children with cystic fibrosis.

This study aimed to characterize the pharmacokinetics of tobramycin administered one, two, or three times daily and to develop an optimal dosing scheme for children with cystic fibrosis. Therapeutic drug monitoring data were obtained from children hospitalized at three academic medical centres from 2006 to 2012. Population pharmacokinetic models were constructed using NONMEM 7.2. Model-based simulations were performed in Matlab R2012b to identify optimal dosing regimens using pharmacodynamic targets. The pharmacokinetic analysis involved 257 patients with a median age of 8.1 years (range 0.1-18.8). Clearance was estimated as 5.59 L/h and the volume of distribution was 18.90 L. Mean (±SD) maximum serum concentrations were highest among patients dosed once per day (24.1 ± 8.9 µg/mL) and were lower among patients dosed two and three times per day (11.2 ± 1.4 and 8.1 ± 2.4 µg/mL, respectively). Simulations revealed that once daily dosing was the only effective regimen for a Pseudomonas aeruginosa MIC of 1.5 µg/mL and none of the tested regimens reliably achieved the pharmacodynamic target for MICs ≥2 µg/mL. Once daily dosing resulted in higher maximum serum concentrations when compared to multiple-daily dosing. In simulations, once daily dosing was the only regimen to achieve the pharmacodynamic target for all subjects with MICs <2 µg/mL.

Real-World Effectiveness of Intravenous and Oral Antibiotic Stepdown Strategies for Gram-Negative Complicated Urinary Tract Infection With Bacteremia.

Background: Robust data are lacking regarding the optimal route, duration, and antibiotic choice for gram-negative bloodstream infection from a complicated urinary tract infection source (GN-BSI/cUTI). Methods: In this multicenter observational cohort study, we simulated a 4-arm registry trial using a causal inference method to compare effectiveness of the following regimens for GN-BSI/cUTI: complete course of an intravenous ß-lactam (IVBL) or oral stepdown therapy within 7 days using fluoroquinolones (FQs), trimethoprim-sulfamethoxazole (TMP-SMX), or high-bioavailability ß-lactams (HBBLs). Adults treated between January 2016 and December 2022 for Escherichia coli or Klebsiella species GN-BSI/cUTI were included. Propensity weighting was used to balance characteristics between groups. The 60-day recurrence was compared using a multinomial Cox proportional hazards model with probability of treatment weighting. Results: Of 2571 patients screened, 759 (30%) were included. Characteristics were similar between groups. Compared with IVBLs, we did not observe a difference in effectiveness for FQs (adjusted hazard ratio, 1.09 [95% confidence interval, .49-2.43]) or TMP-SMX (1.44 [.54-3.87]), and the effectiveness of TMP-SMX/FQ appeared to be optimal at durations of >10 days. HBBLs were associated with nearly 4-fold higher risk of recurrence (adjusted hazard ratio, 3.83 [95% confidence interval, 1.76-8.33]), which was not mitigated by longer treatment durations. Most HBBLs (67%) were not optimally dosed for bacteremia. Results were robust to multiple sensitivity analyses. Conclusions: These real-world data suggest that oral stepdown therapy with FQs or TMP-SMX have similar effectiveness as IVBLs. HBBLs were associated with higher recurrence rates, but dosing was suboptimal. Further data are needed to define optimal dosing and duration to mitigate treatment failures.

Oral ß-Lactams, Fluoroquinolones, or Trimethoprim-Sulfamethoxazole for Definitive Treatment of Uncomplicated Escherichia coli or Klebsiella Species Bacteremia From a Urinary Tract Source.

Background: Fluoroquinolones (FQs) are effective for oral step-down therapy for gram-negative bloodstream infections but are associated with unfavorable toxic effects. Robust data are lacking for trimethoprim-sulfamethoxazole (TMP-SMX) and high-bioavailability ß-lactams (HBBLs). Methods: In this multicenter observational cohort study, we simulated a 3-arm registry trial using causal inference methods to compare the effectiveness of FQs, TMP-SMX, or HBBLs for gram-negative bloodstream infections oral step-down therapy. The study included adults treated between January 2016 and December 2022 for uncomplicated Escherichia coli or Klebsiella species bacteremia of urinary tract origin who were who were transitioned to an oral regimen after ≤4 days of effective intravenous antibiotics. Propensity weighting was used to balance characteristics between groups. 60-day recurrence was compared using a multinomial Cox proportional hazards model with probability of treatment weighting. Results: Of 2571 patients screened, 648 (25%) were included. Their median age (interquartile range) was 67 (45-78) years, and only 103 (16%) were male. Characteristics were well balanced between groups. Compared with FQs, TMP-SMX had similar effectiveness (adjusted hazard ratio, 0.91 [95% confidence interval, .30-2.78]), and HBBLs had a higher risk of recurrence (2.19 [.95-5.01]), although this difference was not statistically significant. Most HBBLs (70%) were not optimally dosed for bacteremia. A total antibiotic duration ≤8 days was associated with a higher recurrence rate in select patients with risk factors for failure. Conclusions: FQs and TMP-SMX had similar effectiveness in this real-world data set. HBBLs were associated with higher recurrence rates but suboptimal dosing may have contributed. Further studies are needed to define optimal BL dosing and duration to mitigate treatment failures.

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.

Analysis of why boron avoids sp2 †hybridization and classical structures in the BnHn+2 series.

We performed global minimum searches for the B(n) H(n+2) (n=2-5) series and found that classical structures composed of 2c-2e B-H and B-B bonds become progressively less stable along the series. Relative energies increase from 2.9 kcal mol(-1) in B(2) H(4) to 62.3 kcal mol(-1) in B(5) H(7). We believe this occurs because boron atoms in the studied molecules are trying to avoid sp(2)  hybridization and trigonal structure at the boron atoms, as in that case one 2p-AO is empty, which is highly unfavorable. This affinity of boron to have some electron density on all 2p-AOs and avoiding having one 2p-AO empty is a main reason why classical structures are not the most stable configurations and why multicenter bonding is so important for the studied boron-hydride clusters as well as for pure boron clusters and boron compounds in general.

Impact of Early Oral Antibiotic Therapy in Infants With Bacteremic Urinary Tract Infections.

OBJECTIVES: To determine the effect of early conversion to oral antibiotics in infants ≤90 days with gram-negative bacteremia and concomitant urinary tract infection on hospital length of stay (LOS) and 30-day revisits for urinary tract infection. DESIGN: This retrospective cohort study included infants ≤ 90 days who had concomitant positive blood and urine cultures with gram-negative bacteremia at 22 hospitals from January 1, 2002 through January 31, 2020. Early oral conversion was defined as a maximum intravenous (IV) duration of 4 days. We conducted a noninferiority test to compare early oral conversion to long IV therapy. A propensity score framework was used to assess comparisons in survey-weighted regression models using matched weights. RESULTS: Among 174 infants, 73 infants received early oral conversion. The LOS was shorter in infants receiving early oral conversion compared to long IV therapy (median 2 days [interquartile range 2, 3] vs 4 days [3, 5]), descriptively (P < .001) and in noninferiority analysis (ratio = 0.43; 90% CI 0.35, 0.53, P < .001). Thirty-day revisits occurred in 5 of 174 (2.8%) of total patients. Early oral conversion did not meet our noninferiority criteria for the 30-day revisits (odds ratio: 4.22, 90%; confidence interval: 0.83, 21.34, P = .91). CONCLUSIONS: Early oral conversion was associated with shorter LOS. The rate of 30-day revisit rates overall was low.

Medication and Fluid Management of Pediatric Sepsis and Septic Shock.

Sepsis is a life-threatening response to infection that contributes significantly to neonatal and pediatric morbidity and mortality worldwide. The key tenets of care include early recognition of potential sepsis, rapid intervention with appropriate fluids to restore adequate tissue perfusion, and empiric antibiotics to cover likely pathogens. Vasoactive/inotropic agents are recommended if tissue perfusion and hemodynamics are inadequate following initial fluid resuscitation. Several adjunctive therapies have been suggested with theoretical benefit, though definitive recommendations are not yet supported by research reports. This review focuses on the recommendations for medication and fluid management of pediatric sepsis and septic shock, highlighting issues related to antibiotic choices and antimicrobial stewardship, selection of intravenous fluids for resuscitation, and selection and use of vasoactive/inotropic medications. Controversy remains regarding resuscitation fluid volume and type, antibiotic choices depending upon infectious risks in the patient's community, and adjunctive therapies such as vitamin C, corticosteroids, intravenous immunoglobulin, and methylene blue. We include best practice recommendations based on international guidelines, a review of primary literature, and a discussion of ongoing clinical trials and the nuances of therapeutic choices.

National Healthcare Safety Network 2018 Baseline Neonatal Standardized Antimicrobial Administration Ratios.

BACKGROUND: The microbiologic etiologies, clinical manifestations, and antimicrobial treatment of neonatal infections differ substantially from infections in adult and pediatric patient populations. In 2019, the Centers for Disease Control and Prevention developed neonatal-specific (Standardized Antimicrobial Administration Ratios SAARs), a set of risk-adjusted antimicrobial use metrics that hospitals participating in the National Healthcare Safety Network's (NHSN's) antimicrobial use surveillance can use in their antibiotic stewardship programs (ASPs). METHODS: The Centers for Disease Control and Prevention, in collaboration with the Vermont Oxford Network, identified eligible patient care locations, defined SAAR agent categories, and implemented neonatal-specific NHSN Annual Hospital Survey questions to gather hospital-level data necessary for risk adjustment. SAAR predictive models were developed using 2018 data reported to NHSN from eligible neonatal units. RESULTS: The 2018 baseline neonatal SAAR models were developed for 7 SAAR antimicrobial agent categories using data reported from 324 neonatal units in 304 unique hospitals. Final models were used to calculate predicted antimicrobial days, the SAAR denominator, for level II neonatal special care nurseries and level II/III, III, and IV NICUs. CONCLUSIONS: NHSN's initial set of neonatal SAARs provides a way for hospital ASPs to assess whether antimicrobial agents in their facility are used at significantly higher or lower rates compared with a national baseline or whether an individual SAAR value is above or below a specific percentile on a given SAAR distribution, which can prompt investigations into prescribing practices and inform ASP interventions.

The impact of beta-lactam allergy labels on hospitalized children.

BACKGROUND AND OBJECTIVES: Antibiotic allergy labels are common and are frequently inaccurate. Previous studies among adults demonstrate that ß-lactam allergy labels may lead to adverse outcomes, including prescription of broader-spectrum antibiotics, increased costs, and increased lengths of stay, among others. However, data among pediatric patients are lacking, especially in the United States. In this study, we sought to determine the impact of ß-lactam allergy labels in hospitalized children with regards to clinical and economic outcomes. METHOD: This retrospective cohort study included pediatric patients 30 days to 17 years old, hospitalized at Intermountain Healthcare facilities from 2007 to 2017, who received ≥1 dose of an antibiotic during their admission. Patients with ß-lactam allergies were matched to nonallergic patients based on age, sex, clinical service line, admission date, academic children's hospital or other hospital admission, and the presence of chronic, comorbid conditions. Outcomes included receipt of broader-spectrum antibiotics, clinical outcomes including length of stay and readmission, and antibiotic and hospitalization costs. RESULTS: In total, 38,906 patients were identified. The prevalence of antibiotic allergy increased from 0.9% among those < 1 year peaked at 10.6% by age 17. Patients with ß-lactam allergy received broader-spectrum antibiotics and experienced higher antibiotic costs than nonallergic controls. However, there were no differences in the length of stay, readmission rates, or total number of days of antibiotics between allergic and nonallergic patients. CONCLUSIONS: Hospitalized pediatric patients with ß-lactam allergy labels receive broader-spectrum antibiotics and experience increased antibiotic costs. This represents an important opportunity for allergy delabeling and antibiotic stewardship.