Antibiotic stewardship in the emergency department setting: Focus on oral antibiotic selection for adults with skin and soft tissue infections.

PURPOSE: An advisory panel of experts was convened by the ASHP Foundation as a part of its Medication-Use Evaluation Resources initiative to provide commentary on an approach to antibiotic stewardship in the treatment of skin and soft tissue infections (SSTIs), with a focus on oral antibiotics in the emergency department (ED) setting for patients who will be treated as outpatients. Considerations include a need to update existing guidelines to reflect new antibiotics and susceptibility patterns, patient-specific criteria impacting antibiotic selection, and logistics unique to the ED setting. SUMMARY: While national guidelines serve as the gold standard on which to base SSTI treatment decisions, our advisory panel stressed that institutional guidelines must be regularly updated and grounded in local antimicrobial resistance patterns, patient-specific factors, and logistical considerations. Convening a team of experts locally to establish institution-specific guidelines as part of a comprehensive antibiotic stewardship program can ensure patients receive the most appropriate oral therapy for the outpatient treatment of SSTIs in patients visiting the ED. CONCLUSION: SSTI treatment considerations for antibiotic selection in the ED supported by current, evidence-based guidelines, including guidance on optimal oral antibiotic selection for patients discharged for outpatient treatment, are a useful tool to improve the quality and efficiency of care, enhance patient-centric outcomes and satisfaction, decrease healthcare costs, and reduce overuse of antibiotics.

Gut colonization with multidrug resistant organisms in the intensive care unit: a systematic review and meta-analysis.

BACKGROUND: Gut colonization with multidrug-resistant organisms (MDRO) frequently precedes infection among patients in the intensive care unit (ICU), although the dynamics of colonization are not completely understood. We performed a systematic review and meta-analysis of ICU studies which described the cumulative incidence and rates of MDRO gut acquisition. METHODS: We systematically searched PubMed, Embase, and Web of Science for studies published from 2010 to 2023 reporting on gut acquisition of MDRO in the ICU. MDRO were defined as multidrug resistant non-Pseudomonas Gram-negative bacteria (NP-GN), Pseudomonas spp., and vancomycin-resistant Enterococcus (VRE). We included observational studies which obtained perianal or rectal swabs at ICU admission (within 48 h) and at one or more subsequent timepoints. Our primary outcome was the incidence rate of gut acquisition of MDRO, defined as any MDRO newly detected after ICU admission (i.e., not present at baseline) for all patient-time at risk. The study was registered with PROSPERO, CRD42023481569. RESULTS: Of 482 studies initially identified, 14 studies with 37,305 patients met criteria for inclusion. The pooled incidence of gut acquisition of MDRO during ICU hospitalization was 5% (range: 1-43%) with a pooled incidence rate of 12.2 (95% CI 8.1-18.6) per 1000 patient-days. Median time to acquisition ranged from 4 to 26 days after ICU admission. Results were similar for NP-GN and Pseudomonas spp., with insufficient data to assess VRE. Among six studies which provided sufficient data to perform curve fitting, there was a quasi-linear increase in gut MDRO colonization of 1.41% per day which was stable through 30 days of ICU hospitalization (R2 = 0.50, p < 0.01). CONCLUSIONS: Acquisition of gut MDRO was common in the ICU and increases with days spent in ICU through 30 days of follow-up. These data may guide future interventions seeking to prevent gut acquisition of MDRO in the ICU.

Review of the In Vitro Microbiological Activity of Mecillinam Against Common Uropathogens in Uncomplicated Urinary Tract Infection: Focus on Resistant Pathogens.

Antimicrobial resistance in uropathogens commonly causing urinary tract infections (UTIs) is a growing problem internationally. Pivmecillinam, the oral prodrug of mecillinam, has been used for over 40 years, primarily in Northern Europe and Canada. It is recommended in several countries as a first-line agent for the treatment of uncomplicated UTIs (uUTIs) and is now approved in the United States. We performed a structured literature search to review the available evidence on susceptibility of common uUTI-causing uropathogens to mecillinam. Among 38 studies included in this literature review, susceptibility rates for Escherichia coli to mecillinam-including resistant phenotypes such as extended-spectrum ß-lactamase-producing E. coli-exceed 90% in most studies. High rates of susceptibility were also reported among many other uropathogens including Klebsiella spp., Enterobacter spp., and Citrobacter spp. In the current prescribing climate within the United States, pivmecillinam represents a viable first-line treatment option for patients with uUTI.

Piperacillin/tazobactam Susceptibility Test Interpretive Criteria for Enterobacterales: Recommendations from the United States Committee on Antimicrobial Susceptibility Testing.

The in vitro susceptibility testing interpretive criteria (STIC) for TZP against Enterobacterales were recently updated by the Food and Drug Administration (FDA), Clinical & Laboratory Standards Institute (CLSI), and European Committee on Antimicrobial Susceptibility Testing (EUCAST). The United States Committee on Antimicrobial Susceptibility Testing (USCAST) also recently reviewed TZP STIC for Enterobacterales and arrived at different STIC for Enterobacterales and herein we explain our recommendations and rationale behind them. Based on our review of the available data, USCAST does not recommend TZP STIC for certain Enterobacterales species that have a moderate to high likelihood of clinically significant AmpC production (E. cloacae, C. freundii, and K. aerogenes only) or for third-generation cephalosporin-non-susceptible (3GC-NS) Enterobacterales. USCAST recommends a TZP susceptibility breakpoint of ≤ 16/4 mg/L for third-generation cephalosporin-susceptible (3GC-S) Enterobacterales but only endorses the use of extended infusion TZP regimens for patients with infections due to these pathogens.

Healthcare Resource Utilization and Discharge Readiness in Adult Hospitalized Patients With Candidemia or Invasive Candidiasis Who Received an Echinocandin: An Analysis of United States Hospitals.

Background: Scant real-world outcomes data are available among hospitalized patients with candidemia (C) or invasive candidiasis without candidemia (IC) who were treated with an echinocandin and few have assessed if there is an opportunity to accelerate the transition of their care to the outpatient setting. This study described the outcomes associated with echinocandin therapy for C/IC and determined the proportion of patients on an echinocandin at hospital discharge (HD) who were potentially eligible for an earlier HD. Methods: A retrospective, multicenter observational study was performed using the PINC AI Healthcare Database (January 2016-April 2019) of hospitalized adult patients with C/IC who received ≥3 days of an echinocandin. Outcomes included post-index culture hospital costs and discharge location. Patients were considered potentially dischargeable earlier than actual HD day if they met the following 3 criteria prior to their actual HD day: resided on a non-intensive care unit hospital ward until HD, received any oral medications, and had no diagnostic/therapeutic interventions. Results: A total of 1865 patients met study criteria. Mean (standard deviation) post-index culture hospital costs for patients with C and IC were 50 196 (64 630) US dollars and 61 551 (73 080) US dollars, respectively. Of the 1008 patients on an echinocandin near HD and discharged alive, 432 (42.9%) were potentially dischargeable prior to their actual hospital day. Most patients (35.8%) were discharged to a long-term care facility. Conclusions: The findings suggest that a high proportion of hospitalized C/IC patients receiving an echinocandin near the time of HD were potentially dischargeable earlier. Like all studies of this nature, the findings need to be prospectively validated.

Machine Learning-Led Optimization of Combination Therapy: Confronting the Public Health Threat of Extensively Drug Resistant Gram-Negative Bacteria.

Developing optimized regimens for combination antibiotic therapy is challenging and often performed empirically over many clinical studies. Novel implementation of a hybrid machine-learning pharmacokinetic/pharmacodynamic/toxicodynamic (ML-PK/PD/TD) approach optimizes combination therapy using human PK/TD data along with in vitro PD data. This study utilized human population PK (PopPK) of aztreonam, ceftazidime/avibactam, and polymyxin B along with in vitro PDs from the Hollow Fiber Infection Model (HFIM) to derive optimal multi-drug regimens de novo through implementation of a genetic algorithm (GA). The mechanism-based PD model was constructed based on 7-day HFIM experiments across 4 clinical, extensively drug resistant Klebsiella pneumoniae isolates. GA-led optimization was performed using 13 different fitness functions to compare the effects of different efficacy (60%, 70%, 80%, or 90% of simulated subjects achieving bacterial counts of 102 CFU/mL) and toxicity (66% of simulated subjects having a target polymyxin B area under the concentration-time curve [AUC] of 100 mg·h/L and aztreonam AUC of 1,332 mg·h/L) on the optimized regimen. All regimens, except those most heavily weighted for toxicity prevention, were able to achieve the target efficacy threshold (102 CFU/mL). Overall, GA-based regimen optimization using preclinical data from animal-sparing in vitro studies and human PopPK produced clinically relevant dosage regimens similar to those developed empirically over many years for all three antibiotics. Taken together, these data provide significant insight into new therapeutic approaches incorporating ML to regimen design and treatment of resistant bacterial infections.

Incidence of acute kidney injury (AKI) and its impact on patient outcomes among adult hospitalized patients with carbapenem-resistant Gram-negative infections who received targeted treatment with a newer ß-lactam or ß-lactam/ß-lactamase inhibitor-, polymyxin- or aminoglycoside-containing regimen.

BACKGROUND: Limited comparative data exist on acute kidney injury (AKI) risk and AKI-associated outcomes in hospitalized patients with carbapenem-resistant Gram-negative infections (CR-GNIs) treated with a newer ß-lactam/ß-lactam-ß-lactamase inhibitor (BL/BL-BLI)-, polymyxin (PB)- or aminoglycoside (AG)-containing regimen. This study quantified the risk of AKI and AKI-related outcomes among patients with CR-GNIs treated with a newer BL/BL-BLI-, PB- or AG-containing regimen. METHODS: A multicentre, retrospective, observational study was performed (2016-20). The study included adult hospitalized patients with (i) baseline estimated glomerular filtration rates ≥30 mL/min/1.73 m2; (ii) CR-GN pneumonia, complicated urinary tract infection or bloodstream infection; and (iii) receipt of newer BL/BL-BLI, PG or AG within 7 days of index CR-GN culture for ≥3 days. Outcomes included AKI, in-hospital mortality and hospital costs. RESULTS: The study included 750 patients and most (48%) received a newer BL/BL-BLI. The median (IQR) treatment duration was 8 (5-11), 5 (4-8) and 7 (4-8) days in the newer BL/BL-BLI group, AG group and PB group, respectively. The PB group had the highest adjusted AKI incidence (95% CI) (PB: 25.1% (15.6%-34.6%) versus AG: 8.9% (5.7%-12.2%) versus newer BL/BL-BLI: 11.9% (8.1%-15.7%); P = 0.001). Patients with AKI had significantly higher in-hospital mortality (AKI: 18.5% versus 'No AKI': 5.6%; P = 0.001) and mean hospital costs (AKI: $49 192 versus 'No AKI': $38,763; P = 0.043). CONCLUSIONS: The AKI incidence was highest among PB patients and patients with AKI had worse outcomes. Healthcare systems should consider minimizing the use of antibiotics that augment AKI risk as a measure to improve outcomes in patients with CR-GNIs.

Impact of a Purified Microbiome Therapeutic on Abundance of Antimicrobial Resistance Genes in Patients With Recurrent Clostridioides difficile Infection.

BACKGROUND: The gastrointestinal microbiota is an important line of defense against colonization with antimicrobial resistant (AR) bacteria. In this post hoc analysis of the phase 3 ECOSPOR III trial, we assessed impact of a microbiota-based oral therapeutic (fecal microbiota spores, live; VOWST Oral Spores [VOS], formerly SER-109]; Seres Therapeutics) compared with placebo, on AR gene (ARG) abundance in patients with recurrent Clostridioides difficile infection (rCDI). METHODS: Adults with rCDI were randomized to receive VOS or placebo orally for 3 days following standard-of-care antibiotics. ARG and taxonomic profiles were generated using whole metagenomic sequencing of stool at baseline and weeks 1, 2, 8, and 24 posttreatment. RESULTS: Baseline (n = 151) and serial posttreatment stool samples collected through 24 weeks (total N = 472) from 182 patients (59.9% female; mean age: 65.5 years) in ECOSPOR III as well as 68 stool samples obtained at a single time point from a healthy cohort were analyzed. Baseline ARG abundance was similar between arms and significantly elevated versus the healthy cohort. By week 1, there was a greater decline in ARG abundance in VOS versus placebo (P = .003) in association with marked decline of Proteobacteria and repletion of spore-forming Firmicutes, as compared with baseline. We observed abundance of Proteobacteria and non-spore-forming Firmicutes were associated with ARG abundance, while spore-forming Firmicutes abundance was negatively associated. CONCLUSIONS: This proof-of-concept analysis suggests that microbiome remodeling with Firmicutes spores may be a potential novel approach to reduce ARG colonization in the gastrointestinal tract.

Priorities and Progress in Gram-negative Bacterial Infection Research by the Antibacterial Resistance Leadership Group.

Addressing the treatment and prevention of antibacterial-resistant gram-negative bacterial infections is a priority area of the Antibacterial Resistance Leadership Group (ARLG). The ARLG has conducted a series of observational studies to define the clinical and molecular global epidemiology of carbapenem-resistant and ceftriaxone-resistant Enterobacterales, carbapenem-resistant Pseudomonas aeruginosa, and carbapenem-resistant Acinetobacter baumannii, with the goal of optimizing the design and execution of interventional studies. One ongoing ARLG study aims to better understand the impact of fluoroquinolone-resistant gram-negative gut bacteria in neutropenic patients, which threatens to undermine the effectiveness of fluoroquinolone prophylaxis in these vulnerable patients. The ARLG has conducted pharmacokinetic studies to inform the optimal dosing of antibiotics that are important in the treatment of drug-resistant gram-negative bacteria, including oral fosfomycin, intravenous minocycline, and a combination of intravenous ceftazidime-avibactam and aztreonam. In addition, randomized clinical trials have assessed the safety and efficacy of step-down oral fosfomycin for complicated urinary tract infections and single-dose intravenous phage therapy for adult patients with cystic fibrosis who are chronically colonized with P. aeruginosa in their respiratory tract. Thus, the focus of investigation in the ARLG has evolved from improving understanding of drug-resistant gram-negative bacterial infections to positively affecting clinical care for affected patients through a combination of interventional pharmacokinetic and clinical studies, a focus that will be maintained moving forward.

Priorities and Progress in Gram-positive Bacterial Infection Research by the Antibacterial Resistance Leadership Group: A Narrative Review.

The Antibacterial Resistance Leadership Group (ARLG) has prioritized infections caused by gram-positive bacteria as one of its core areas of emphasis. The ARLG Gram-positive Committee has focused on studies responding to 3 main identified research priorities: (1) investigation of strategies or therapies for infections predominantly caused by gram-positive bacteria, (2) evaluation of the efficacy of novel agents for infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci, and (3) optimization of dosing and duration of antimicrobial agents for gram-positive infections. Herein, we summarize ARLG accomplishments in gram-positive bacterial infection research, including studies aiming to (1) inform optimal vancomycin dosing, (2) determine the role of dalbavancin in MRSA bloodstream infection, (3) characterize enterococcal bloodstream infections, (4) demonstrate the benefits of short-course therapy for pediatric community-acquired pneumonia, (5) develop quality of life measures for use in clinical trials, and (6) advance understanding of the microbiome. Future studies will incorporate innovative methodologies with a focus on interventional clinical trials that have the potential to change clinical practice for difficult-to-treat infections, such as MRSA bloodstream infections.

International consensus recommendations for the use of prolonged-infusion beta-lactam antibiotics: Endorsed by the American College of Clinical Pharmacy, British Society for Antimicrobial Chemotherapy, Cystic Fibrosis Foundation, European Society of Clinical Microbiology and Infectious Diseases, Infectious Diseases Society of America, Society of Critical Care Medicine, and Society of Infectious Diseases Pharmacists: An executive summary.

Intravenous ß-lactam antibiotics remain a cornerstone in the management of bacterial infections due to their broad spectrum of activity and excellent tolerability. ß-lactams are well established to display time-dependent bactericidal activity, where reductions in bacterial burden are directly associated with the time that free drug concentrations remain above the minimum inhibitory concentration (MIC) of the pathogen during the dosing interval. In an effort to take advantage of these bactericidal characteristics, prolonged (extended and continuous) infusions (PI) can be applied during the administration of intravenous ß-lactams to increase time above the MIC. PI dosing regimens have been implemented worldwide, but implementation is inconsistent. We report consensus therapeutic recommendations for the use of ß-lactam PI developed by an expert international panel with representation from clinical pharmacy and medicine. This consensus guideline provides recommendations regarding pharmacokinetic and pharmacodynamic targets, therapeutic drug monitoring considerations, and the use of PI ß-lactam therapy in the following patient populations: severely ill and nonseverely ill adult patients, pediatric patients, and obese patients. These recommendations provide the first consensus guidance for the use of ß-lactam therapy administered as PIs and have been reviewed and endorsed by the American College of Clinical Pharmacy (ACCP), the British Society for Antimicrobial Chemotherapy (BSAC), the Cystic Fibrosis Foundation (CFF), the European Society of Clinical Microbiology and Infectious Diseases (ESCMID), the Infectious Diseases Society of America (IDSA), the Society of Critical Care Medicine (SCCM), and the Society of Infectious Diseases Pharmacists (SIDP).

International consensus recommendations for the use of prolonged-infusion beta-lactam antibiotics: Endorsed by the American College of Clinical Pharmacy, British Society for Antimicrobial Chemotherapy, Cystic Fibrosis Foundation, European Society of Clinical Microbiology and Infectious Diseases, Infectious Diseases Society of America, Society of Critical Care Medicine, and Society of Infectious Diseases Pharmacists.

Intravenous ß-lactam antibiotics remain a cornerstone in the management of bacterial infections due to their broad spectrum of activity and excellent tolerability. ß-lactams are well established to display time-dependent bactericidal activity, where reductions in bacterial burden are directly associated with the time that free drug concentrations remain above the minimum inhibitory concentration (MIC) of the pathogen during the dosing interval. In an effort to take advantage of these bactericidal characteristics, prolonged (extended and continuous) infusions (PIs) can be applied during the administration of intravenous ß-lactams to increase time above the MIC. PI dosing regimens have been implemented worldwide, but implementation is inconsistent. We report consensus therapeutic recommendations for the use of PI ß-lactams developed by an expert international panel with representation from clinical pharmacy and medicine. This consensus guideline provides recommendations regarding pharmacokinetic and pharmacodynamic targets, therapeutic drug-monitoring considerations, and the use of PI ß-lactam therapy in the following patient populations: severely ill and nonseverely ill adult patients, pediatric patients, and obese patients. These recommendations provide the first consensus guidance for the use of ß-lactam therapy administered as PIs and have been reviewed and endorsed by the American College of Clinical Pharmacy (ACCP), the British Society for Antimicrobial Chemotherapy (BSAC), the Cystic Fibrosis Foundation (CFF), the European Society of Clinical Microbiology and Infectious Diseases (ESCMID), the Infectious Diseases Society of America (IDSA), the Society of Critical Care Medicine (SCCM), and the Society of Infectious Diseases Pharmacists (SIDP).

Clinical Risk Scores to Predict Nonsusceptibility to Trimethoprim-Sulfamethoxazole, Fluoroquinolone, Nitrofurantoin, and Third-Generation Cephalosporin Among Adult Outpatient Episodes of Complicated Urinary Tract Infection.

Background: Clinical risk scores were developed to estimate the risk of adult outpatients having a complicated urinary tract infection (cUTI) that was nonsusceptible to trimethoprim-sulfamethoxazole (TMP-SMX), fluoroquinolone, nitrofurantoin, or third-generation cephalosporin (3-GC) based on variables available on clinical presentation. Methods: A retrospective cohort study (1 December 2017-31 December 2020) was performed among adult members of Kaiser Permanente Southern California with an outpatient cUTI. Separate risk scores were developed for TMP-SMX, fluoroquinolone, nitrofurantoin, and 3-GC. The models were translated into risk scores to quantify the likelihood of nonsusceptibility based on the presence of final model covariates in a given cUTI outpatient. Results: A total of 30 450 cUTIs (26 326 patients) met the study criteria. Rates of nonsusceptibility to TMP-SMX, fluoroquinolone, nitrofurantoin, and 3-GC were 37%, 20%, 27%, and 24%, respectively. Receipt of prior antibiotics was the most important predictor across all models. The risk of nonsusceptibility in the TMP-SMX model exceeded 20% in the absence of any risk factors, suggesting that empiric use of TMP-SMX may not be advisable. For fluoroquinolone, nitrofurantoin, and 3-GC, clinical risk scores of 10, 7, and 11 predicted a ≥20% estimated probability of nonsusceptibility in the models that included cumulative number of prior antibiotics at model entry. This finding suggests that caution should be used when considering these agents empirically in patients who have several risk factors present in a given model at presentation. Conclusions: We developed high-performing parsimonious risk scores to facilitate empiric treatment selection for adult outpatients with cUTIs in the critical period between infection presentation and availability of susceptibility results.

Treatment of critically ill patients with cefiderocol for infections caused by multidrug-resistant pathogens: review of the evidence.

Appropriate antibiotic treatment for critically ill patients with serious Gram-negative infections in the intensive care unit is crucial to minimize morbidity and mortality. Several new antibiotics have shown in vitro activity against carbapenem-resistant Enterobacterales (CRE) and difficult-to-treat resistant Pseudomonas aeruginosa. Cefiderocol is the first approved siderophore beta-lactam antibiotic with potent activity against multidrug-resistant, carbapenem-resistant, difficult-to-treat or extensively drug-resistant Gram-negative pathogens, which have limited treatment options. The spectrum of activity of cefiderocol includes drug-resistant strains of Acinetobacter baumannii, P. aeruginosa, Stenotrophomonas maltophilia, Achromobacter spp. and Burkholderia spp. and CRE that produce serine- and/or metallo-carbapenemases. Phase 1 studies established that cefiderocol achieves adequate concentration in the epithelial lining fluid in the lung and requires dosing adjustment for renal function, including patients with augmented renal clearance and continuous renal-replacement therapy (CRRT); no clinically significant drug-drug interactions are expected. The non-inferiority of cefiderocol versus high-dose, extended-infusion meropenem in all-cause mortality (ACM) rates at day 14 was demonstrated in the randomized, double-blind APEKS-NP Phase 3 clinical study in patients with nosocomial pneumonia caused by suspected or confirmed Gram-negative bacteria. Furthermore, the efficacy of cefiderocol was investigated in the randomized, open-label, pathogen-focused, descriptive CREDIBLE-CR Phase 3 clinical study in its target patient population with serious carbapenem-resistant Gram-negative infections, including hospitalized patients with nosocomial pneumonia, bloodstream infection/sepsis, or complicated urinary tract infections. However, a numerically greater ACM rate with cefiderocol compared with BAT led to the inclusion of a warning in US and European prescribing information. Cefiderocol susceptibility results obtained with commercial tests should be carefully evaluated due to current issues regarding their accuracy and reliability. Since its approval, real-world evidence in patients with multidrug-resistant and carbapenem-resistant Gram-negative bacterial infections suggests that cefiderocol can be efficacious in certain critically ill patient groups, such as those requiring mechanical ventilation for COVID-19 pneumonia with subsequently acquired Gram-negative bacterial superinfection, and patients with CRRT and/or extracorporeal membrane oxygenation. In this article, we review the microbiological spectrum, pharmacokinetics/pharmacodynamics, efficacy and safety profiles and real-world evidence for cefiderocol, and look at future considerations for its role in the treatment of critically ill patients with challenging Gram-negative bacterial infections.

Real-world effectiveness of omadacycline and impact of unapproved omadacycline prescription claims among adult outpatients with community-acquired bacterial pneumonia or acute bacterial skin and skin structure infections.

BACKGROUND: Omadacycline is an amino-methylcycline antibiotic that is indicated for the treatment of adults with community-acquired bacterial pneumonia (CABP) and acute bacterial skin and skin structure infections (ABSSSI). Like many new antibiotics, there are scant real-world effectiveness data for omadacycline. There is also a high potential that an omadacycline prescription is rejected or reversed, and it is not known whether patients who have an unapproved omadacycline claim are at higher risk for 30-day emergency department (ED)/inpatient (IP) visits. OBJECTIVE: To describe the real-world effectiveness of omadacycline and assess the impact of unapproved omadacycline claims among adult outpatients with CABP or ABSSSIs. METHODS: The study population included patients who received 1 or more omadacycline outpatient prescriptions from a large US claims database (October 2018 to September 2020) and had a diagnosis for CABP or ABSSSI. The approval status of omadacycline claims was determined. The proportion of all-cause 30-day ED/IP visits among patients with an approved vs unapproved claim was compared. RESULTS: 404 patients met the inclusion criteria (CABP: 97; ABSSSI: 307). Of the 404 patients, 146 (36%) had an unapproved claim (CABP: 28; ABSSSI: 118). Overall, the proportion of 30-day ED/IP visits (yes/no) for those with an unapproved and approved claim was 28% vs 17%, respectively (P < 0.05). The overall adjusted 30-day ED/IP visits incidence difference was 11% (95% CI = 2 - 19), corresponding to an adjusted number needed to treat of 9 (95% CI = 5 - 43). CONCLUSIONS: A high incidence (36%) of unapproved omadacydine claims was observed in this study. Patients with unapproved daims had an 11% higher incidence of 30-day all-cause ED/IP visits than patients with approved claims. DISCLOSURES This study was funded by Paratek Pharmaceuticals, Inc (King of Prussia, PA). Dr Lodise is a consultant to Paratek Pharmaceuticals, Inc, and has received consultancy payments. Drs Gunter, Sandor, and Berman are employees and shareholders of Paratek Pharmaceuticals, Inc. Dr Mu, Ms Gao, Ms Yang, and Ms Yim are employees of Analysis Group. Analysis Group has received payment from Paratek Pharmaceuticals, Inc, to conduct part of this study.

Economic Impact of Recurrent Clostridioides difficile Infection in the USA: A Systematic Literature Review and Cost Synthesis.

INTRODUCTION: Up to 35% of patients with a first episode of Clostridioides difficile infection (CDI) develop recurrent CDI (rCDI), and of those, up to 65% experience multiple recurrences. A systematic literature review (SLR) was conducted to review and summarize the economic impact of rCDI in the United States of America. METHODS: English-language publications reporting real-world healthcare resource utilization (HRU) and/or direct medical costs associated with rCDI in the USA were searched in MEDLINE, MEDLINE In-Process, Embase, and the Cochrane Library databases over the past 10 years (2012-2022), as well as in selected scientific conferences that publish research on rCDI and its economic burden over the past 3 years (2019-2022). HRU and costs identified through the SLR were synthesized to estimate annual rCDI-attributable direct medical costs to inform the economic impact of rCDI from a US third-party payer's perspective. RESULTS: A total of 661 publications were retrieved, and 31 of them met all selection criteria. Substantial variability was found across these publications in terms of data source, patient population, sample size, definition of rCDI, follow-up period, outcomes reported, analytic approach, and methods to adjudicate rCDI-attributable costs. Only one study reported rCDI-attributable costs over 12 months. Synthesizing across the relevant publications using a component-based cost approach, the per-patient per-year rCDI-attributable direct medical cost was estimated to range from $67,837 to $82,268. CONCLUSIONS: While real-world studies on economic impact of rCDI in the USA suggested a high-cost burden, inconsistency in methodologies and results reporting warranted a component-based cost synthesis approach to estimate the annual medical cost burden of rCDI. Utilizing available literature, we estimated the average annual rCDI-attributable medical costs to allow for consistent economic assessments of rCDI and identify the budget impact on US payers.

Cost-Effectiveness Analysis of REBYOTA™ (Fecal Microbiota, Live-jslm [FMBL]) Versus Standard of Care for the Prevention of Recurrent Clostridioides difficile Infection in the USA.

INTRODUCTION: Recurrent Clostridioides difficile infection (rCDI) is common and associated with considerable clinical and economic consequences. REBYOTA™ (fecal microbiota, live-jslm [FMBL]) is a microbiota-based live biotherapeutic approved for the prevention of rCDI following antibiotic treatment for rCDI. We sought to evaluate cost-effectiveness of FMBL compared to standard of care (SOC) from a US third-party payer perspective among patients with one or more (≥ 1) recurrences. METHODS: A Markov model with a lifetime time horizon was developed. The model population included adult patients who had ≥ 1 recurrence after a primary CDI episode and had completed ≥ 1 round of antibiotics, or had ≥ 2 severe CDI episodes resulting in hospitalization within the last year. The model consisted of six health states with an 8-week model cycle: rCDI, absence of CDI after recurrence, colectomy, ileostomy, ileostomy reversal, and death. Drug costs and rCDI-related medical costs were estimated in 2022 US dollars and discounted at 3% annually. Deterministic sensitivity analyses were performed. RESULTS: Compared to SOC, FMBL at $9000/course resulted in an incremental cost-effectiveness ratio (ICER) of $18,727 per quality-adjusted life year (QALY) gained. The incremental cost was $5336 (FMBL $79,236, SOC $73,900) and the incremental effectiveness was 0.285 QALYs (FMBL 10.346, SOC 10.061). The cumulative drug acquisition and administration costs for the FMBL and SOC arms were $24,245 and $16,876, while rCDI-related medical costs for FMBL and SOC were $54,991 and $57,024, respectively. The ICER in the subgroup of patients at first recurrence was $13,727 per QALY gained. FMBL remained cost-effective across all sensitivity analyses. CONCLUSIONS: FMBL was found to be cost-effective compared to SOC for the prevention of rCDI with more benefits among patients at first recurrence, with an ICER far below the payer ICER threshold of $100,000. Patients treated with FMBL experienced higher total QALYs and reduced healthcare resource utilization, including reduced hospitalizations.

Budget Impact Analysis of REBYOTA™ (Fecal Microbiota, Live-jslm [FMBL]) for Preventing Recurrent Clostridioides difficile Infection in the US.

INTRODUCTION: Patients with Clostridioides difficile infection (CDI) often experience recurrences (rCDI), which are associated with high morbidity, mortality, and healthcare expenditures. REBYOTA™ (fecal microbiota, live-jslm [FMBL]) is a microbiota-based live biotherapeutic approved for the prevention of rCDI following antibiotic treatment for rCDI. We quantified the budget impact of FMBL during the first 3 years following introduction from a third-party US payer perspective. METHODS: A decision-tree model was used to estimate the budget impact of one-course FMBL by comparing costs under the scenario with FMBL to the scenario without FMBL (standard of care) in patients with one or more (≥ 1) recurrences after a primary episode of CDI and had completed ≥ 1 round of antibiotic treatments. Drug costs, rCDI-related medical costs, and budget impact over 1-3 years were estimated in 2022 US dollars. One-way sensitivity analyses were performed. RESULTS: For an insurance plan with a population size of 1,000,000, 468 patients per year were estimated to have ≥ 1 rCDI. The budget impact of one-course FMBL at $9000/course was cost-saving at an¼ average of -$0.0039 on a per-member-per-month (PMPM) basis, an average of -$8.30 on a per-treated-member-per-month (PTMPM) basis, and a total of -$139,865 on a plan level assuming 5%, 15%, and 20% of patients receive FMBL over 1-3 years, respectively. The scenario with FMBL entry was associated with higher drug costs (difference at $0.0474 PMPM; $101.26 PTMPM; $1,706,445 total plan) and lower rCDI-related medical costs (difference at -$0.0513 PMPM; -$109.56 PTMPM; -$1,846,309 total plan). The budget impact of FMBL in patients at first rCDI was cost-saving at -$0.0139 PMPM, -$84.78 PTMPM, corresponding to an annual savings of $500,022. CONCLUSIONS: FMBL has a cost-saving budget impact for a US payer, with higher initial drug costs being offset by savings in rCDI-related medical costs. Greater cost saving was found in patients at first recurrence.

Methods to appraise available evidence and adequacy of data from a systematic literature review to conduct a robust network meta-analysis of treatment options for patients with hospital-acquired or ventilator-associated bacterial pneumonia.

We aimed to determine if available evidence from a previously conducted systematic literature review was sufficient to conduct a robust network meta-analysis (NMA) using the International Society for Pharmacoeconomics and Outcomes Research Good Practice Task Force NMA study questionnaire to evaluate suitability, relevance, and credibility of available randomized-controlled trials (RCT) of antibacterial therapies for treatment of patients with hospital-acquired or ventilator-associated bacterial pneumonia (HABP/VABP). We assessed feasibility and reliability of an NMA for a connected network of RCTs, and then relevance and credibility of the connected network for informing decision-making. This previously conducted systematic literature review using Cochrane dual-reviewer methodology, Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and PICOTS (population, interventions, comparators, outcomes, timing, and setting) criteria identified 25 citations between 2001 and 2018; 18 were unique RCTs. Trial design characteristics, outcome definitions, assessment time points, and analyses populations varied across studies. Using "clinical response," an efficacy end point to health technology assessment agencies, we assessed potential network credibility, which collapsed from the overall data set to four studies and five interventions. This did not include closed loop(s) needed to assess consistency. Of the studies reporting clinical response, >70% of patients were ventilated at baseline with mean Acute Physiologic Assessment and Chronic Health Evaluation II scores from 14.7 to 17.5. Pseudomonas aeruginosa (range, 18.4-64.1%) and Klebsiella spp. (range, 1.6-49%) were the most common causative pathogens. We identified relevant RCTs for most standard-of-care agents approved for HABP/VABP, which provided a comprehensive evidence base. In summary, our appraisal of available evidence for the clinical response outcome among adult patients with HABP/VABP does not support the conduct of a scientifically robust and clinically meaningful NMA. Although this data is vital to registration, there are significant limitations in these trials for health technology assessments, payor decisions, guidelines, and protocol decisions.