bluuebunny/crossref_metadata_2025_split huggingface dataset:
2260. Differences in the Prevalence of Inappropriate Antibiotic Prescribing by Payer Type
Authors: Ladines-Lim Joseph B , Chua Kao-Ping , Fischer Michael , Linder Jeffrey A 
Published: November 2023

Abstract

Background
Understanding the relationship between inappropriate prescribing and patient insurance type could inform the targeting of antibiotic stewardship initiatives. However, few national data on this topic exist.

Methods
We analyzed the National Ambulatory Medical Care Survey, a nationally representative survey of office-based physician visits. We included all years from 2016 to 2019 except 2017, a year during which the survey was not fielded. We identified visits resulting in an oral antibiotic prescription among children and non-elderly adults who were privately insured, publicly insured, or uninsured. The exposure was safety-net status (publicly insured/uninsured versus privately insured). The outcome was inappropriate antibiotic prescribing, defined as an antibiotic prescription in a visit for which none of the diagnosis codes justified antibiotic use (following the approach of Chua et al, BMJ 2019). We assessed the association between safety-net status and inappropriate antibiotic prescribing using linear regression, controlling for patient characteristics, calendar quarter, and specialty. Models accounted for the complex design of the survey and employed designed-based variance estimators.

Results
Of 413,830,032 weighted visits for children, 16.9% resulted in an antibiotic prescription. Among these visits, the unadjusted prevalence of inappropriate antibiotic prescriptions was 29.1% overall, 23.4% for safety-net patients, and 32.4% for privately insured patients (adjusted difference, safety-net minus private: -11.9%, 95% CI: -20.6%, -3.2%). Of 1,240,610,825 weighted visits for non-elderly adults, 11.0% resulted in an antibiotic prescription. Among these visits, the unadjusted prevalence of inappropriate antibiotic prescriptions was 50.1% overall, 60.7% for safety-net patients, and 47.9% for privately insured patients (adjusted difference, safety-net minus private: 11.3%, 95% CI: 2.4%, 20.3%).

Conclusion
Safety-net status was associated with a lower rate of inappropriate antibiotic prescribing among children but a higher rate among non-elderly adults. Antibiotic stewardship initiatives targeting clinicians who care for privately insured children and adults with safety-net insurance may be warranted.

Disclosures
Jeffrey A. Linder, MD, MPH, FACP, Amgen, Biogen, Eli Lily: Stocks/Bonds
2950. Guideline discordant antibiotic treatment in the Emergency Department is associated with increased adverse events and length of stay
Authors: Breeden Maddy , Chanderraj Rishi , Petty Lindsay A 
Published: November 2023

Abstract

Background
Skin and soft tissue infections (SSTI) are the 3rd most common infectious disease treated in the Emergency Department (ED). Observational studies have shown poor adherence to IDSA guidelines in the ED. While there are numerous descriptive studies of guideline-discordant antibiotic treatment for SSTI in the ED, less is known about the impact of discordance on outcomes.
Figure 1
Inappropriate antibiotic treatment is associated with an increased hospital stay in patients admitted with a skin and soft tissue infection (Mean length of stay 4.62 days among appropriately treated patients and 10.63 days in inappropriately treated patients).

Methods
In this retrospective cohort study, 214 consecutive SSTI admissions treated with IV antibiotics at the Ann Arbor Veterans Affairs Hospital from 2020-2022 were reviewed by 2 Infectious Diseases physicians. Guideline concordance was adjudicated based on IDSA guidelines. Outcomes were hospital length of stay (LOS) and incidence of hospital-associated adverse events as defined by the Center for Medicare Services. The primary exposure was the concordance of antibiotic treatment with IDSA guidelines. Covariates included demographics, the burden of medical comorbidities by the Charlson index, and the severity of illness measured by the Severe Organ Failure Score (SOFA). We modeled the risk of hospital-associated adverse events with a multivariable logistic regression model and hospital LOS with a multivariable Poisson model.

Results
Of 214 patients with SSTI treated with IV antibiotics, only 15.7% (N=19) received guideline-concordant therapy, and only 32% (N=69) had indications for IV treatment. 27 patients (12.6%) had a hospital-associated adverse event. Vancomycin was the most common inappropriate antibiotic (n=76, 35%), and kidney injury was the most common adverse event (n=12, 9.8%). Guideline-discordant antibiotic treatment was associated with an increased length of stay after adjusting for covariates (0.83 more hospital days in guideline discordant, 95% CI 0.73-0.93 hospital days, p=0.027, Figure 1), and increased odds of hospital-associated adverse events (OR 1.03, 95% CI 1.002-1.08, p=0.04).

Conclusion
Guideline-discordant therapy for SSTI in the ED was associated with unnecessary IV treatment, longer hospitalization, and increased hospital-associated adverse outcomes. Stewardship interventions should target treatment of SSTI in the ED to improve patient outcomes.

Disclosures
All Authors: No reported disclosures
2278. The Safety of Aztreonam vs. Ceftazidime in Patients with Penicillin Allergy: A Matched Cohort Study
Authors: Tan Jun Jie , Zhou Peijun Yvonne , Chua Nathalie Grace Sy , Hung Kai Chee , Lee Winnie , Lee Lai Wei , Le Lim Jia , Lim Yun Chun Shena , Liew Yixin , Loo Li Wen , Koomanan Narendran S/O , Tang Sarah , Teoh Boon San , Yii Daphne , Thien Siew Yee , Cherng Pei Zhi Benjamin , Chlebicki Maciej Piotr , Kwa Andrea , Chung Shimin Jasmine 
Published: November 2023

Abstract

Background
Penicillin allergy (PA) is the most common drug allergy and is reported in up to 15% of hospitalized patients. Traditionally, aztreonam (AZT), a monobactam with low cross-reactivity to penicillin (PCN), has been recommended as an alternative antibiotic for patients with PA in our institutional empiric antibiotic guidelines. However, due to global AZT shortage in 2022, ceftazidime (CTZ), a cephalosporin with similar R1-side chain to AZT and low cross-reactivity to PCN, was used as a substitute for AZT. Fortuitously, this was cheaper - AZT (SGD $44.03 per 1g vial) vs CTZ (SGD $2.86 per 1g vial). There is a paucity of real-world data on the safety of CTZ in patients with PA. We proceeded to evaluate our experience with using CTZ as an alternative to AZT.

Methods
This is a 1:1 matched, retrospective cohort study comparing patients with PA who received AZT from October 2022 to December 2022, with those who received CTZ from December 2022 to February 2023. They were matched based on severity of allergic reaction (AR) to PCN, age and gender. The risk of AR was stratified as low, medium or high based on the classification provided by the American Academy of Allergy, Asthma and Immunology. The severity of AR was based on the Delphi study grading system. The primary outcome was development of AR after initiation of AZT or CTZ. The secondary safety outcomes include hepatotoxicity and neurotoxicity.

Results
There were 132 patients: 52 patients (39.4%) were males, with a median age of 70 (IQR, 61 – 76) years, and majority were Chinese (n = 84 (63.6%)). The number of patients with low, medium and high risk of AR to PCN were 60 (45.4%), 54 (40.9%), and 18 (13.6%) respectively. The incidence of AR was similar in both groups: 1 patient (1.52%) in AZT arm vs 2 patients (3.03%) in CTZ arm (p = 1.0). The patient in the AZT arm had generalized urticaria (Grade 2). Both patients in the CTZ arm developed localized skin reaction (Grade 1). All 3 patients were deemed high risk of developing AR to PCN. Another patient in the AZT arm developed hepatotoxicity (raised alanine phosphatase and alanine transaminase), with a Naranjo score of 3 (possible adverse drug reaction).

Conclusion
CTZ is a safe alternative to AZT for patients labelled with PA, and may be a more cost-effective alternative in our setting.

Disclosures
All Authors: No reported disclosures
2280. Surveillance of Life-Long Antibiotics (SOLLA) 2: Patients on Life-Long Antibiotics in an Australian Healthcare Network
Authors: van Leerdam Taylah , Lau Jillian , Woolley Ian , Browne Mitchell , O’Bryan Jessica 
Published: November 2023

Abstract

Background
There is a range of conditions for which long-term antibiotics are prescribed, most of which lack high quality evidence. Apart from promoting antimicrobial resistance, long-term antibiotics also impact the individual patient, disrupting the normal microbiome, and increasing the risk of infection with multi-resistant organisms (MROs). Previous work conducted at Monash Health, in Victoria, Australia, in 2014 noted great heterogeneity in both indications for prolonged antibiotic courses and the antimicrobial agents used.

Methods
The current study aimed to reassess prescribing trends within the same health network, across two time periods in 2019 and 2021. Outpatient prescriptions were extracted from the Monash Health pharmaceutical database at two time points, from 1st January 2019 – 30th June 2019, and 1st January 2021 – 30th June 2021.

Results
From 4,704 outpatient prescriptions, 929 patients were identified as being on either one or more antibiotics for an intended duration of ≥ 12 months. There were a total 536 (57.7%) males and 393 females (42.3%), with a mean age of 58.20 years. Sixty-eight patients died between the two follow-up periods. Data was separated into 3 groups: primary prophylaxis in the setting of immunosuppression (n = 687), secondary prophylaxis for infections deemed incurable (n = 78), and “Other” (n = 164). Six hundred and four patients (88%) on primary prophylaxis were for Pneumocystis jirovecii pneumonia, and 83 (12%) post splenectomy. Trimethoprim/sulfamethoxazole was predominantly prescribed for PJP prophylaxis (n = 583), followed by dapsone (n = 21). Prosthetic joint infections made up 57 (73%) of those on suppressive antibiotics for infections deemed incurable. An array of antibiotics was utilised to treat them, as seen in Figure 1. The “Other” category included those on antibiotics for difficult to treat infections, such as mycobacterial infections (n = 43), chronic airways disease (n = 38), spontaneous bacterial peritonitis (n = 23) and recurrent urinary tract infections (n = 12). Data on comorbidities, hospitalisations and MROs between groups can be viewed in Table 1.

Conclusion
Further research is needed. Prospective data examining long-term patient outcomes, and patterns of prescribing across different health networks would be of benefit.

Disclosures
Jillian Lau, MBBS, FRACP, Gilead: Advisor/Consultant|Gilead: Grant/Research Support|MSD: Grant/Research Support|Viiv Healthcare: Advisor/Consultant Ian Woolley, MBBS, FRACP, DTM&H, MD, Gilead: Educational support, investigator for Gilead supported trial|MSD: educational support, participation in a clinical trial|Pfizer: Educational support|ViiV: Educational Programs, Advisory Board member, ViiV sponsored trials
2290. Neurological Symptoms of Long - COVID in Mexican Ambulatory Adults with Mild COVID-19
Authors: Díaz-Ramírez Jorge-Baruch , Marquez Jorge Bryan Ortega , González-Valadez Yazmín , Cortazar-Maldonado Luis-Alberto , Morales-Fernández José-Antonio , Pérez-Sastré Miguel A , Rojas Roberto Martínez , Trujillo García Leopoldo D , García Martha Fragoso , Salinas Diana Mondragón , Hernández Lissete Navarrete , Acosta Diana Pérez , García-León Miguel Leonardo , Bautista-Carbajal Patricia , Ángel-Ambrocio Antonio H , Camacho-Morales Jorge , Villa Antonio R , Wong-Chew Rosa-María 
Published: November 2023

Abstract

Background
The COVID-19 pandemic represents one of the greatest public health crises in this century . Since the beginning of the pandemic there were reports of persistence of symptoms after an average recovery period of 2-5 weeks. Long-COVID syndrome was defined as a continuation or onset of symptoms within 3 months of the initial infection, lasting for at least 2 months with no explanation. There are few studies focused on neurological symptoms of long COVID in ambulatory patients who suffered a mild disease.

Methods
We conducted a prospective cohort study with a univariate and Kaplan-Meier survival analysis with data obtained between January 2020 to November 2022 from ambulatory adults with mild to moderate COVID-19 diagnosed at our UNAM Faculty of Medicine COVID-19 Diagnostic Center in Mexico City. Patients were systematically called every 15 days during 6 months to evaluate self-perceived neurological symptoms after being diagnosed.

Results
We assessed 169 COVID 19 patients, the mean age was 39 (SD 15) years, 42% were men, 97% were Mexican, 90% developed a new neurologic symptom after the COVID-19 acute period. The most common symptoms reported during the follow up were in the first 21 days: fatigue (84%), headache (70%), sleep disorders (69%), sadness (61%), concentration difficulties (60%), emotional liability (57%), anger (56%) and irritability (55%) among others. The highest cumulative incidence (per 1,000 persons) was for headache (187), fatigue (168), sleep disorders (108), concentration difficulties (88), anger (81), dizziness (79), paresthesia (73), speaking and thinking difficulties (67) among others.
The survival analysis showed an increased cumulative probability to develop neurological symptoms during the 6 months follow-up, with the highest risk for headache (50%) and fatigue (40%).

Conclusion
The probability of presenting neurologic symptoms after suffering a mild COVID 19 disease increased during the 6 months follow up. Additionally, most symptoms were of new onset after the initial recovery from an acute mild COVID-19 episode or persisted from the initial illness and fluctuated over the follow-up, except for seizures that were present as an isolated symptom during acute phase and absent during the follow-up.

Disclosures
All Authors: No reported disclosures
2294. Severity and characteristics of patients hospitalized during Delta and Omicron-predominant COVID-19 time periods in Los Angeles County
Authors: Greene Carmon , Sato Heidi D , OYong Kelsey , Traub Elizabeth , Rubin Zachary 
Published: November 2023

Abstract

Background
We examined risk factors and disease severity in patients hospitalized during Delta and Omicron SARS COV-2-predominant periods in a diverse metro area.

Methods
A retrospective cohort study was conducted using data reported to Los Angeles County Department of Public Health on adults aged 18 years and older with a laboratory-confirmed COVID (PCR/NAAT) test collected on or within 14 days of hospital admission between 6/19/2021 - 1/3/2023. Case data were matched with: 1) California Immunization Registry data to determine vaccination status and 2) whole genome sequencing results when available.
Infection with an inferred variant was defined as having a laboratory collection date during the time period when the variant exceeded 50% of sequenced specimens (Delta-predominant period: 6/19/2021-12/11/2021; Omicron-predominant period: 12/18/2021-1/3/2023). Confirmed infection was defined as having a sequenced specimen with either Delta or Omicron variant. Demographic and clinical metrics were examined (Tables 1-4). Patients with Delta and Omicron were compared using Chi-square tests. P-values &lt; 0.05 were considered statistically significant.

Results
During the study period, 13,790 inferred Delta and 38,264 inferred Omicron hospitalized cases were reported. 2,660 cases (of 61,983 sequenced specimens) had confirmed Delta and 1,983 (of 61,534 sequenced specimens) had confirmed Omicron infections. Cases hospitalized with both inferred and confirmed Delta were more likely to have a COVID-related hospitalization, admitted to ICU and longer length of stay (Tables 3, 4). Cases hospitalized with both inferred and confirmed Omicron were significantly older and more likely to have a comorbidity (Tables 3, 4).

Conclusion
Based on the longer length of stay and higher ICU admission, COVID patients hospitalized during the Delta-predominant time period have a more severe outcome and are more likely to have COVID-related diagnoses than COVID patients hospitalized during the Omicron-predominant time period.
This study was limited by an unadjusted analysis, which did not control for potential confounders during the different time periods, such as vaccination coverage, prior infections, hospital capacity, and percent of sequenced specimens.

Disclosures
All Authors: No reported disclosures
2953. PK/PD Comparison of a New Dosing Scheme for Meropenem Adapted to Outpatient Parenteral Antimicrobial Therapy (OPAT) in Non-Critically-Ill Patients
Authors: Briquet Caroline , Pharmacist Hospital , Ngougni Pokem Perrin , Wijnant Gert-Jan , Cornu Olivier , Yildiz Halil , Van Bambeke Françoise , Cyr Yombi Jean 
Published: November 2023

Abstract

Background
A pilot OPAT project has been started in Belgium for the continuation at home of the treatment (initiated in hospital) of patients infected by multi-resistant Gram-negative bacteria when no oral options are available. In Belgium, meropenem is the only available carbapenem, but its limited stability at room temperature does not allow a sustained administration over 12 or 24 h via IV pumps. As the replacement of the perfusion is not feasible after working hours for home care nurses, the aim of this prospective study was to compare the pharmacokinetic profile and time above MIC for 2g meropenem administered TID (20 minutes infusion) over 12h (typically at 8h,14h, 20h) in comparison with the traditional 24h regimen (typically at 8h,16h, 24h).

Methods
Patients received first meropenem 2g q8h. At steady state ( &gt; 3 doses), 4 blood samples were collected over 8h. The penultimate day of the treatment, patients were switched to the OPAT-compatible dosage regimen (2g q6h over 12h) and, at steady state, a total of 8 blood samples were collected during the first and third dosing intervals. Unbound meropenem concentrations were determined in ultrafiltrated plasma by a validated LC-MS/MS procedure. Time above MICs ≤ 8 mg/L (EUCAST susceptibility breakpoint) were estimated for both schemes based on PK profiles.

Results
Twenty-two patients were included. The mean pharmacokinetic profile for each scheme is shown in the Figure 1. The Table 1 shows that plasma concentrations remained &gt; 4 mg/L during 100% time with the conventional scheme and &gt; 2 mg/L with the OPAT-compatible scheme but still at least ∼80% time &gt; 8 mg/L with both therapeutic schemes. Periods of inadequate coverage are spread at the end of each dose with the conventional dosing regimen but essentially concentrated overnight with the new scheme.

Conclusion
PK/PD models recommend for meropenem therapeutic schemes with plasma concentrations &gt; MIC during 30-40% of the time in non-critically ill patients. This target is easily achieved with the proposed OPAT-compatible dosing regimen, including during night, and could therefore be safely used in a context of limited nurse resources.

Disclosures
All Authors: No reported disclosures
2304. Surveillance strategies for the detection of new SARS-CoV-2 variants across epidemiological contexts
Authors: Roster Kirstin Oliveira , Kissler Stephen M , Omoregie Enoma , Wang Jade , Amin Helly , Di Lonardo Steve , Hughes Scott , Grad Yonatan H 
Published: November 2023

Abstract

Background
Rapid identification of new SARS-CoV-2 variants is a critical component of the public health response to the COVID-19 pandemic. However, we lack a quantitative framework to assess the expected performance of sampling strategies in varying epidemic contexts.

Methods
To address this gap, we used a multi-patch stochastic model of SARS-CoV-2 spread in New York City to evaluate the impact of the volume of testing and sequencing, geographic representativeness of sampling, location and timing of variant emergence, and relative variant transmissibility on the time to first detection of a new variant.

Results
The strategy of targeted sampling of likely emergence locations offered the most improvement in detection speed. Increasing sequencing capacity reduced detection time more than increasing testing volumes. The relative transmissibility of the new variant and the epidemic context of variant emergence also influenced detection times, showing that individual surveillance strategies can result in a wide range of detection outcomes, depending on the underlying dynamics of the circulating variants.
Detection time by test volume and fixed sequencing capacity.
Lines depict the mean duration between variant introduction and detection in days as a function of daily testing volume, colored by the maximum sequencing volume (A), and as a function of daily maximum sequencing volume, colored by the test volume (B) (at variant introduction 50 days after the prior variant and baseline sampling strategy).
Detection time by proportion of tests allocated in a single location.
Lines depict the average detection time for scenarios where between 20% and 100% of tests are sampled from a single location, and the remaining tests are evenly distributed across the remaining locations by population size. The lines distinguish between scenarios where the variant emerged in the primary allocation location, i.e., test over-sampling and emergence occurred in the same location (blue), and scenarios where the variant emerged in one of the other locations, i.e., test over-sampling and emergence occurred in different locations (red). Ribbons depict the 95% confidence interval for the detection time.

Conclusion
These findings help contextualize the design, interpretation, and trade-offs of genomic surveillance strategies.

Disclosures
Stephen M. Kissler, PhD, ModernaTx: Advisor/Consultant Yonatan H. Grad, MD, PhD, Day Zero Diagnostics: Board Member|GSK: Advisor/Consultant