Patterns, Predictors, and Intercenter Variability in Empiric Gram-Negative Antibiotic Use Across 928 United States Hospitals

Regional Variation of Infectious Agents Causing Endogenous Endophthalmitis in the United States: A National Database Analysis

OBJECTIVE

To describe regional variation in microbes causing infectious endogenous endophthalmitis (EE) in the United States.

DESIGN

This is a retrospective, national database analysis utilizing the 2002-2014 National Inpatient Sample database.

SUBJECTS

Using the International Classification of Disease 9 codes, we identified cases with EE. Cases were stratified regionally into Northeast, South, West, or Midwest.

METHODS

Unadjusted chi-square analysis followed by adjusted multivariate logistic regression was performed to evaluate variation in demographic factors, comorbidities using the Elixhauser Comorbidity Index (ECI), microbial variation, mortality, and use of vitrectomy or enucleation by region.

MAIN OUTCOME MEASURES

Proportion of microbes, mortality, and vitrectomy by region in addition to factors with significant odds ratios for mortality and for in-hospital vitrectomy.

RESULTS

A total of 10 912 patients with infectious EE were identified, with 2063 cases in the Northeast (18.9%), 2145 cases in the Midwest (19.7%), 4134 cases in the South (37.9%), and 2570 cases in the West (23.6%). Chi-square analysis indicated significant regional variation in patient demographics, microbes causing the infection, ECI, mortality, and surgical intervention. The 4 most common microbes for all regions were methicillin-sensitive Staphylococcus aureus (MSSA), Streptococcus, Candida, and methicillin-resistant Staphylococcus aureus. Methicillin-sensitive S. aureus was the most common cause of EE in all regions, although the proportion of MSSA infection did not significantly vary by region (P = 0.03). Further, there was significant regional variation in the proportion of other microbes causing the infection (P < 0.001). Higher rates of vitrectomies were seen in the South and Midwest regions than that in the Northeast and West (P = 0.04).

CONCLUSIONS

Regional variation exists in the infectious microbes causing EE. Further studies are needed to elucidate the etiology of these variations.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Carbapenem use in extended-spectrum cephalosporin-resistant Enterobacterales infections in US hospitals and influence of IDSA guidance: a retrospective cohort study

BACKGROUND

Disparate and rapidly changing practice recommendations from major professional infectious diseases societies for managing non-severe infections caused by extended-spectrum β-lactamase-producing Enterobacterales might hamper carbapenem stewardship. We aimed to understand the real-world management of extended-spectrum cephalosporin-resistant (ECR) Enterobacterales infections in US hospitals and factors influencing preference for carbapenems over alternative treatments.

METHODS

This retrospective cohort study included adults (aged ≥18 years) admitted to hospital with ECR Enterobacterales infections in the PINC AI database. Antibiotic regimens were assessed during empirical and targeted treatment periods and by infection severity and site. Likelihood of receiving targeted carbapenems over time and before or after initial release of the Infectious Diseases Society of America (IDSA) guidance on Sept 8, 2020, was established with generalised estimating equations controlling for patient, hospital, and temporal confounders.

FINDINGS

Between Jan 1, 2018, and Dec 31, 2021, 30 041 inpatient encounters with ECR Enterobacterales infections were identified at 168 US hospitals, of which 16 006 (53·3%) encounters were in women and 14 035 (46·7%) were in men, with a mean age of 67·3 years (SD 15·1). Although few patients received carbapenems empirically (5324 [17·7%] of 30 041), many did so as targeted treatment (17 518 [58·3%] of 30 041), including subgroups of patients without septic shock (3031 [45·6%] of 6651) and patients with urinary tract infections without septic shock (1845 [46·8%] of 3943) in whom specific narrower-spectrum alternatives were active. Transitions from non-carbapenem to carbapenem antibiotics occurred most often on the day that the ECR phenotype was reported, regardless of illness severity. Carbapenems were the predominant choice to treat ECR Enterobacterales infections over time (adjusted odds ratio 1·00 [95% CI 1·00-1·00]), with no additional immediate change (1·07 [0·95-1·20]) or sustained change (0·99 [0·98-1·00]) after IDSA guidance release.

INTERPRETATION

High carbapenem use in targeting non-severe ECR Enterobacterales infections in US hospitals predates 2020 IDSA guidance and has persisted thereafter. Efforts to increase awareness and implementation of recommendations among clinicians to use carbapenem-sparing alternatives in ECR Enterobacterales infections might decrease global carbapenem selective pressure.

FUNDING

US National Institutes of Health Intramural Research Program, National Institute of Allergy and Infectious Diseases, and US Food and Drug Administration.

Exploring variations in recommended first-choice therapy for complicated urinary tract infections in males: Insights from outpatient settings across age, race, and ethnicity

INTRODUCTION

There are known disparities in the treatment of infectious diseases. However, disparities in treatment of complicated urinary tract infections (UTIs) are largely uninvestigated.

OBJECTIVES

We characterized UTI treatment among males in Veterans Affairs (VA) outpatient settings by age, race, and ethnicity and identified demographic characteristics predictive of recommended first-choice antibiotic therapy.

METHODS

We conducted a national, retrospective cohort study of male VA patients diagnosed with a UTI and dispensed an outpatient antibiotic from January 2010 through December 2020. Recommended first-choice therapy for complicated UTI was defined as use of a recommended first-line antibiotic drug choice regardless of area of involvement (ciprofloxacin, levofloxacin, or sulfamethoxazole/trimethoprim) and a recommended duration of 7 to 10 days of therapy. Multivariable models were used to identify demographic predictors of recommended first-choice therapy (adjusted odds ratio [aOR] > 1).

RESULTS

We identified a total of 157,898 males diagnosed and treated for a UTI in the outpatient setting. The average antibiotic duration was 9.4 days (±standard deviation [SD] 4.6), and 47.6% of patients were treated with ciprofloxacin, 25.1% with sulfamethoxazole/trimethoprim, 7.6% with nitrofurantoin, and 6.6% with levofloxacin. Only half of the male patients (50.6%, n = 79,928) were treated with recommended first-choice therapy (first-line drug choice and appropriate duration); 77.6% (n = 122,590) were treated with a recommended antibiotic choice and 65.9% (n = 104,070) with a recommended duration. Age 18-49 years (aOR 1.07, 95% confidence interval [CI] 1.03-1.11) versus age ≥65 years was the only demographic factor predictive of recommended first-choice therapy.

CONCLUSIONS

Nearly half of the patients included in this study did not receive recommended first-choice therapies; however, racial and ethnic disparities were not identified. Underutilization of recommended first-choice antibiotic therapy in complicated UTIs continues to be an area of focus for antimicrobial stewardship programs.

Clinicians' interpretation of thresholds in hospital antibiograms for gram-negative rod infections: A survey and contingent valuation study of hospitalists

Clinical guidelines suggest that hospital antibiograms are a key component when deciding empiric therapy, but little is known about how often clinicians use antibiograms and how they influence clinicians' empiric therapy decisions. We surveyed hospitalists at seven healthcare systems in the United States on their reported practices related to antibiograms and their hypothetical prescribing for four clinical scenarios associated with gram-negative rod pathogens. Each was given a randomly assigned antibiogram susceptibility percentage, and we used contingent valuation analysis to assess whether the antibiogram susceptibility percentage was associated with prescribing practices. Of the 193 survey responders, only 52 (26.9%) respondents reported using antibiograms more than monthly. Across all four clinical scenarios, there was no evidence that antibiogram susceptibility levels influenced antibiotic prescribing practices. With limited utilization and no evidence that they influenced practice, antibiograms may have a limited role in hospitalist care delivery for common gram-negative rod infections.

Health Equity and Antibiotic Prescribing in the United States: A Systematic Scoping Review

We performed a scoping review of articles published from 1 January 2000 to 4 January 2022 to characterize inequities in antibiotic prescribing and use across healthcare settings in the United States to inform antibiotic stewardship interventions and research. We included 34 observational studies, 21 cross-sectional survey studies, 4 intervention studies, and 2 systematic reviews. Most studies (55 of 61 [90%]) described the outpatient setting, 3 articles were from dentistry, 2 were from long-term care, and 1 was from acute care. Differences in antibiotic prescribing were found by patient's race and ethnicity, sex, age, socioeconomic factors, geography, clinician's age and specialty, and healthcare setting, with an emphasis on outpatient settings. Few studies assessed stewardship interventions. Clinicians, antibiotic stewardship experts, and health systems should be aware that prescribing behavior varies according to both clinician- and patient-level markers. Prescribing differences likely represent structural inequities; however, no studies reported underlying drivers of inequities in antibiotic prescribing.

Physician antimicrobial prescribing and patient outcomes on general medical wards: a multicentre retrospective cohort study

BACKGROUND

Variability in antimicrobial prescribing may indicate an opportunity for improvement in antimicrobial use. We sought to measure physician-level antimicrobial prescribing in adult general medical wards, assess the contribution of patient-level factors to antimicrobial prescribing and evaluate the association between antimicrobial prescribing and clinical outcomes.

METHODS

Using the General Medicine Inpatient Initiative (GEMINI) database, we conducted a retrospective cohort study of physician-level volume and spectrum of antimicrobial prescribing in adult general medical wards in 4 academic teaching hospitals in Toronto, Ontario, between April 2010 and December 2019. We stratified physicians into quartiles by hospital site based on volume of antimicrobial prescribing (days of therapy per 100 patient-days and antimicrobial-free days) and antibacterial spectrum (modified spectrum score). The modified spectrum score assigns a value to each antibacterial agent based on the breadth of coverage. We assessed patient-level differences among physician quartiles using age, sex, Laboratory-based Acute Physiology Score, discharge diagnosis and Charlson Comorbidity Index. We evaluated the association of clinical outcomes (in-hospital 30-day mortality, length of stay, intensive care unit [ICU] transfer and hospital readmission) with antimicrobial volume and spectrum using multilevel modelling.

RESULTS

The cohort consisted of 124 physicians responsible for 124 158 hospital admissions. The median physician-level volume of antimicrobial prescribing was 56.1 (interquartile range 51.7-67.5) days of therapy per 100 patient-days. We did not find any differences in baseline patient characteristics by physician prescribing quartile. The difference in mean prescribing between quartile 4 and quartile 1 was 15.8 days of therapy per 100 patient-days (95% confidence interval [CI] 9.6-22.0), representing 30% higher antimicrobial prescribing in the fourth quartile than the first quartile. Patient in-hospital deaths, length of stay, ICU transfer and hospital readmission did not differ by physician quartile. In-hospital mortality was higher among patients cared for by prescribers with higher modified spectrum scores (odds ratio 1.13, 95% CI 1.04-1.24).

INTERPRETATION

We found that physician-level variability in antimicrobial prescribing was not associated with differences in patient characteristics or outcomes in academic general medicine wards. These findings provide support for considering the lowest quartile of physician antimicrobial prescribing within each hospital as a target for antimicrobial stewardship.

Adherence to Antimicrobial Prophylaxis Guidelines for Elective Surgeries Across 825 US Hospitals, 2019-2020

BACKGROUND

There are limited US data assessing adherence to surgical antimicrobial prophylaxis guidelines, particularly across a large, nationwide sample. Moreover, commonly prescribed inappropriate antimicrobial prophylaxis regimens remain unknown, hindering improvement initiatives.

METHODS

We conducted a retrospective cohort study of adults who underwent elective craniotomy, hip replacement, knee replacement, spinal procedure, or hernia repair in 2019-2020 at hospitals in the PINC AI (Premier) Healthcare Database. We evaluated adherence of prophylaxis regimens, with respect to antimicrobial agents endorsed in the American Society of Health-System Pharmacist guidelines, accounting for patient antibiotic allergy and methicillin-resistant Staphylococcus aureus colonization status. We used multivariable logistic regression with random effects by hospital to evaluate associations between patient, procedural, and hospital characteristics and guideline adherence.

RESULTS

Across 825 hospitals and 521 091 inpatient elective surgeries, 308 760 (59%) were adherent to prophylaxis guidelines. In adjusted analysis, adherence varied significantly by US Census division (adjusted OR [aOR] range: .61-1.61) and was significantly lower in 2020 compared with 2019 (aOR: .92; 95% CI: .91-.94; P < .001). The most common reason for nonadherence was unnecessary vancomycin use. In a post hoc analysis, controlling for patient age, comorbidities, other nephrotoxic agent use, and patient and procedure characteristics, patients receiving cefazolin plus vancomycin had 19% higher odds of acute kidney injury (AKI) compared with patients receiving cefazolin alone (aOR: 1.19; 95% CI: 1.11-1.27; P < .001).

CONCLUSIONS

Adherence to antimicrobial prophylaxis guidelines remains suboptimal, largely driven by unnecessary vancomycin use, which may increase the risk of AKI. Adherence decreased in the first year of the COVID-19 pandemic.

Clinical, contextual and hospital-level factors associated with escalation and de-escalation of empiric Gram-negative antibiotics among US inpatients

Background

Empiric Gram-negative antibiotics are frequently changed in response to new information. To inform antibiotic stewardship, we sought to identify predictors of antibiotic changes using information knowable before microbiological test results.

Methods

We performed a retrospective cohort study. Survival-time models were used to evaluate clinical factors associated with antibiotic escalation and de-escalation (defined as an increase or decrease, respectively, in the spectrum or number of Gram-negative antibiotics within 5 days of initiation). Spectrum was categorized as narrow, broad, extended or protected. Tjur's D statistic was used to estimate the discriminatory power of groups of variables.

Results

In 2019, 2 751 969 patients received empiric Gram-negative antibiotics at 920 study hospitals. Antibiotic escalation occurred in 6.5%, and 49.2% underwent de-escalation; 8.8% were changed to an equivalent regimen. Escalation was more likely when empiric antibiotics were narrow-spectrum (HR 19.0 relative to protected; 95% CI: 17.9-20.1), broad-spectrum (HR 10.3; 95% CI: 9.78-10.9) or extended-spectrum (HR 3.49; 95% CI: 3.30-3.69). Patients with sepsis present on admission (HR 1.94; 95% CI: 1.91-1.96) and urinary tract infection present on admission (HR 1.36; 95% CI: 1.35-1.38) were more likely to undergo antibiotic escalation than patients without these syndromes. De-escalation was more likely with combination therapy (HR 2.62 per additional agent; 95% CI: 2.61-2.63) or narrow-spectrum empiric antibiotics (HR 1.67 relative to protected; 95% CI: 1.65-1.69). Choice of empiric regimen accounted for 51% and 74% of the explained variation in antibiotic escalation and de-escalation, respectively.

Conclusions

Empiric Gram-negative antibiotics are frequently de-escalated early in hospitalization, whereas escalation is infrequent. Changes are primarily driven by choice of empiric therapy and presence of infectious syndromes.

Clinical Characteristics and the Effect of Timing for Metagenomic Next-Generation Sequencing in Critically Ill Patients with Sepsis

Background

Metagenomic next-generation sequencing (mNGS) has a good performance for the identification of pathogens in infectious diseases, but few studies on the clinical characteristics of mNGS and the effect of timing for mNGS in critically ill patients with sepsis.

Methods

We retrospectively included all patients diagnosed with sepsis after admission to the intensive care unit (ICU) of a university-affiliated hospital between Aug 1, 2019 and Apr 1, 2021. During the study period, pathogens for all enrolled subjects were obtained by mNGS. We analyzed the composition and positive rate of different samples type for mNGS. And then we used the univariable and multivariable logistic regression to explore the risk factors associated with all-cause mortality at 28 days.

Results

A total of 87 patients were included and 87 samples were analyzed among these patients. The most common sample for mNGS was bronchoalveolar lavage fluid (BALF), about 84% (73/87). The positive rate of pathogens identification by mNGS was higher than conventional culture (92% vs 36%, p < 0.001). In addition to the pathogens detected by conventional culture, mNGS can detect more viruses and fungi. Based on the mNGS report, clinicians made adjustments to the antibiotic regimen for 72% patients. The multivariate binary logistic regression analysis suggested that age (OR, 1.036; 95% CI, 1.005-1.067; p = 0.021) and the sequential organ failure assessment (SOFA) score on the day of mNGS sampling were independent risk factors of death at 28 days (OR, 1.204; 95% CI, 1.038-1.397; p = 0.014).

Conclusion

In critically ill patients with sepsis, the most common sample type for mNGS was BALF, and the positive rate of mNGS is higher than conventional cultures, especially in viruses and fungi. Meanwhile, mNGS can guide clinicians in adjusting antibiotic regimens. Age and the SOFA score on the day of mNGS sampling were independent risk factors for death.