We detected no correlation between standardized antimicrobial administration ratios (SAARs) and healthcare facility-onset Clostridioides difficile infection (HO-CDI) rates in 102 acute-care Veterans Affairs medical centers over 16 months. SAARs may be useful for investigating trends in local antimicrobial use, but no ratio threshold demarcated HO-CDI risk.

A comparison of computer-extracted and facility-reported counts of hospitalized coronavirus disease 2019 (COVID-19) patients for public health reporting at 36 hospitals revealed 42% of days with matching counts between the data sources. Miscategorization of suspect cases was a primary driver of discordance. Clear reporting definitions and data validation facilitate emerging disease surveillance.

Background: Gram-negative bacteria cause a variety of hospital-associated infections (HAIs). Of concern is Pseudomonas aeruginosa, which is a leading cause of HAIs. Early and adequate therapy of P. aeruginosa blood stream infection (BSI) is associated with decreased mortality. Additionally, infectious disease consultation has also shown to improve health outcomes, streamline care, and decrease costs. Therefore, the goal of this study was to describe treatment of P. aeruginosa BSI and impact of infectious disease consultations on health outcomes. Methods: In this retrospective cohort study, we analyzed national VA medical, encounter, pharmacy, microbiology, and laboratory data from January 1, 2012 to December 31, 2018. The cohort included all hospitalized adult veterans (aged ≥18 years) who had a positive blood culture for P. aeruginosa. Only the first P. aeruginosa blood culture per patient was included, and duplicate cultures within 30 days were removed. Treatment was identified within −2 to +5 days of the culture date. Multidrug-resistant (MDR) cultures were identified based on resistance to at least 1 agent in at least 3 or more antimicrobial categories tested. Multivariable logistic regression models were fit to assess infectious disease consultations and adequate treatment on in-hospital mortality and 30-day mortality. Results: In total, 3,256 patients had a BSI with P. aeruginosa, of which 386 (11.5%) were MDR. Most of these patients were male (97.5%), >65 years of age (70.9%), and non-Hispanic white (63.8%). Also, 784 patients (23.3%) died during hospitalization and 870 (25.8%) died within 30 days of their culture. In multivariable regression models, infectious disease consultations were associated with decreased odds of in-hospital mortality (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.53–0.77) and 30-day mortality (OR, 0.56, 95% CI, 0.48–0.67) even after adjusting for age, race, care setting, Charlson score, and prior healthcare exposures. Furthermore, inadequate definitive treatment was associated with increased odds of in-hospital mortality (OR, 2.77; 95% CI, 1.35–5.69) and 30-day mortality (OR, 2.37; 95% CI, 1.18–4.79), even after adjusting for age, Charlson score, care setting, and prior healthcare exposures. In addition, carbapenem treatment was associated with increased odds of in-hospital mortality (OR, 1.38; 95% CI, 1.12–1.70) and 30-day mortality (OR, 1.49; 95% CI, 1.22–1.81), whereas fluoroquinolone treatment was associated with lower odds of in-hospital mortality (OR, 0.49; 95% CI, 0.41–0.59) and 30-day mortality (OR, 0.60; 95% CI, 0.50–0.71). Finally, extended-spectrum cephalosporin was also associated with lower odds of in-hospital mortality (OR, 0.82; 95% CI, 0.68–0.98). Conclusions: Use of infectious disease consultations and any adequate definitive treatment for those with P. aeruginosa BSI lowered odds of in-hospital and 30-day mortality. Early consultation with infectious disease physicians regarding adequate treatment has direct positive impact on clinical outcomes for patients with P. aeruginosa BSI.

Funding: No

Disclosures: None

Background: Infections caused by Acinetobacter spp are often healthcare acquired and associated with high mortality. Extensively drug-resistant (XDR) Acinetobacter are nonsusceptible to at least 1 agent in all but 2 or fewer antibiotic classes. Few of the new antibiotics targeting multidrug-resistant gram-negative bacteria are effective against XDR Acinetobacter. Recent national guidelines for treatment of resistant gram-negative infections do not include Acinetobacter, leaving a knowledge gap in best practices. Methods: This retrospective cohort study included microbiology, clinical, and pharmacy data from all patients hospitalized between 2012 and 2018 at any Veterans’ Affairs medical center who had cultures that grew XDR Acinetobacter spp. Bivariate unadjusted analyses compared clinical outcomes by monotherapy versus combination therapy. Using mixed-effects ordinal logistic regression, propensity score–adjusted models accounting for severity of illness and other variables associated with treatment were fit to compare outcomes. Results: Of 11,546 patients with 15,364 cultures that grew Acinetobacter spp, 408 patients (3.5%) had 666 cultures (4.3%) with XDR Acinetobacter. Moreover, 276 of these patients (67.6%) had gram-negative targeted antibiotic treatment within −2 to +5 days from the culture. Furthermore, 118 patients (42.8%) received monotherapy, most commonly piperacillin-tazobactam (n = 54, 45.7%) or an anti-Pseudomonas cephalosporin (n = 21, 17.8%). Also, 158 (57.2%) patients received combination therapy, most commonly a carbapenem (n = 93, 58.9%) and/or polymyxin (n = 68, 43.0%). Moreover, 41 patients (25.9%) received both a carbapenem and polymyxin. In both unadjusted and adjusted analyses, there were no significant differences in the odds of 30-day mortality (aOR, 1.43; 95% CI, 0.86–2.38) or 1-year mortality (aOR, 1.04; 95% CI, 0.68–1.60) between combination therapy and monotherapy groups. Among 264 patients (96%) whose cultures occurred during an inpatient or long-term care admission, unadjusted analyses showed increased odds of in-hospital mortality (OR, 1.89; 95% CI, 1.08–3.29) and longer postculture length of stay in the combination therapy group: median, 23 days (IQR, 11–57) versus 14 days (IQR, 7–32) (P = .02). However, with propensity score adjustment, these associations were no longer significant. Furthermore, there was no significant difference in odds of 90-day readmission between groups in either unadjusted or adjusted analyses (aOR, 1.20; 95% CI, 0.74–1.95). Conclusions: In this large national cohort of patients with XDR Acinetobacter cultures, more patients received combination therapy than monotherapy, and carbapenems and polymyxins were the most-used classes. However, there were no significant differences in outcomes between patients receiving combination therapy and monotherapy, suggesting lack of clinical benefit to the common practice of treating XDR Acinetobacter infections with multiple antibiotics. Further research is needed to determine optimal treatment strategies for this pathogen.

Funding: No

Disclosures: None

This is an epidemiological study of carbapenem-resistant Enterobacteriaceae (CRE) in Veterans’ Affairs medical centers (VAMCs). In 2017, almost 75% of VAMCs had at least 1 CRE case. We observed substantial geographic variability, with more cases in urban, complex facilities. This supports the benefit of tailoring infection control strategies to facility characteristics.

Antibiotic prescribing practices across the Veterans’ Health Administration (VA) experienced significant shifts during the coronavirus disease 2019 (COVID-19) pandemic. From 2015 to 2019, antibiotic use between January and May decreased from 638 to 602 days of therapy (DOT) per 1,000 days present (DP), while the corresponding months in 2020 saw antibiotic utilization rise to 628 DOT per 1,000 DP.

Background: Accurate identification of Clostridioides difficile infections (CDIs) from electronic data sources is important for surveillance. We evaluated how frequently laboratory findings were supported by diagnostic coding and treatment data in the electronic health record. Methods: We analyzed a retrospective cohort of patients in the Veterans’ Affairs Health System from 2006 through 2016. A CDI event was defined as a positive laboratory test for C. difficile toxin or toxin genes in the inpatient, outpatient, or long-term care setting with no prior positive test in the preceding 14 days. Events were classified as incident (no CDI in the prior 56 days), or recurrent (CDI in the prior 56 days) and were evaluated for evidence of clinical diagnosis based on International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) and ICD-10-CM codes and at least 1 dose of an anti-CDI agent (intravenous or oral metronidazole, fidaxomicin, or oral vancomycin). We further assessed the possibility of treatment without testing by quantifying positive laboratory tests and diagnostic codes among inpatients receiving an anti-CDI agent. A course of anti-CDI therapy was defined as continuous treatment with the same drug. Results: Among 119,063 incident and recurrent CDI events, 70,114 (58.9%) had a diagnosis code and 15,850 (13.3%) had no accompanying treatment. The proportion of patients with ICD codes was highest among patients treated with fidaxomicin (82.6% of 906) or oral vancomycin (74.3% of 30,777) and was lower among patients receiving metronidazole (63.3% of 103,231) and those without treatment (29.9% of 15,850). The proportion of events with ICD codes and treatment was similar between incident and recurrent episodes. During the study period, there were ~470,000 inpatient courses of metronidazole, fidaxomicin, and oral vancomycin. Table 1 shows the presence of ICD codes and positive laboratory tests by anti-CDI agents. Among 51,100 courses of oral vancomycin, 51% had an ICD code and 44% had a positive test for C. difficile within 7 days of treatment initiation. Among 1,013 courses of fidaxomicin, 79% had an ICD code and 56% had a positive laboratory test. Conclusions: In this large cohort, there was evidence of substantial CDI treatment without confirmatory C. difficile testing and, to a lesser extent, some positive tests without accompanying treatment or coding. A combination of data sources may be needed to more accurately identify CDI from electronic health records for surveillance purposes.

Funding: None

Disclosures: None

Background: Implementation of antimicrobial stewardship programs (ASPs) in acute-care facilities may optimize antibiotic use and decrease antibiotic resistance. To explore the relationship between ASPs and clinical outcomes, we reviewed bivariate relationships between VA Medical Center (VAMC) complexity level and presence of an ASP, presence of an ASP and inpatient antibiotic use, and antibiotic use and antibiotic resistance or Clostridioides difficile infection (CDI). Methods: We conducted a cross-sectional study of national data using the following elements: a detailed survey of antimicrobial stewardship practices at VAMCs in 2012 which included facility complexity designations; data from the VA national Electronic Health Record (EHR) for inpatient antibiotic use (2009–2012 in days of therapy per 1,000 bed days of care); EHR laboratory data in 2013 for antibiotic resistance in E. coli isolates; and 2013 CDI rate data from the VA Inpatient Evaluation Center. These data were reviewed for assessment of the presence of ASPs and for antibiotic use and resistance. We assessed 4 groups of antibiotics for use and resistance: total antibiotics, fluoroquinolones, cephalosporins, and carbapenems. Categorical, t test, or nonparametric analyses were performed, as appropriate. Results: 120 VAMCs were evaluated; 71% had ASPs. Proportions of VAMCs with ASPs were not significantly different by facility complexity level. Differences were observed between presence or absence of ASP and some antibiotic use groups (Table). Presence or absence of an ASP was not statistically associated with a difference in E. coli resistance (any antibiotic group examined) or CDI rates. In addition, antibiotic use (any group) did not statistically associate with E. coli resistance rates, and this result remained unchanged when stratified by presence or absence of an ASP. Conclusions: Total antibiotic use and fluroquinolone use were lower among facilities with ASPs than without, a finding consistent with ASP implementation reducing the amount of antibiotics prescribed. Although we did not find an association between facilities with an ASP and antibiotic resistance or CDI rates in this preliminary review, it sets the stage for future multivariate analyses. Furthermore, given the years of antibiotic use needed for development of resistance, the limited years evaluated may not have been sufficient to determine an impact, highlighting the need for further research into understanding clinical outcomes.

Funding: None

Disclosures: None

Background: Inappropriate use of MRSA-spectrum antibiotics is an important antimicrobial stewardship target. Contributors to inappropriate use include empiric treatment of patients who are determined to not be infected or who are infected but lack MRSA risk factors, and by excessive treatment duration when suspected MRSA infection is disproven. To characterize opportunities for improvement, we conducted a medical use evaluation (MUE) in 27 VA medical centers. The primary objectives were to assess the following proportions: (1) courses of unjustified empiric vancomycin therapy (patients in whom all antibacterials were halted within 2 days or without a principal or secondary discharge infection diagnosis); (2) courses of unjustified continuation of anti-MRSA therapy beyond day 4 (no MRSA risk factors or proven MRSA infection); and (3) excess anti-MRSA days of therapy (DOT), that is, DOT in unjustified empiric courses plus DOT after day 4 in unjustified continued courses. Methods: Clinical pharmacists performed retrospective, structured, manual record reviews of patients started on intravenous vancomycin on day 1 or 2 of hospitalization from June 2017 to May 2018. Exclusion criteria included surgical prophylaxis, recent MRSA infection, β-lactam allergy, renal insufficiency, severe immunosuppression, or infection that warranted anti-MRSA therapy other than vancomycin. Results: Of 2,493 evaluated patients, 1,320 met the inclusion criteria. Among them, 44% of courses were initiated in the emergency department, 37% of patients had ≥1 risk factor for healthcare-associated infections, and 50% of patients had ≥2 SIRS criteria or required vasopressor support. The most common admission diagnoses were skin and soft-tissue infection (SSTI, 40%; 68% nonpurulent) and pneumonia (27%; 46% without healthcare risk factors). Clinical cultures recovered MRSA from 8% of patients. Empiric therapy was not justified in 342 patients (26%; 57% were clinically stable). Continued therapy was unjustified in 46% of the 320 patients who received >4 days of anti-MRSA therapy. Of all days of anti-MRSA therapy, 23% were unjustified; 65% of these were due to unjustified empiric therapy. Site-specific variations in unjustified empiric therapy better correlated with the proportion of unjustified DOT than did unjustified continuation of therapy (Pearson correlation coefficients [PCC], 0.75 and 0.54, respectively) (Fig. 1). Facility-specific proportions of unjustified DOT modestly correlated with anti-MRSA DOT (PCC, 0.45; n = 27) (Fig. 2) but not the anti-MRSA standardized antimicrobial administration ratio (PCC, 0.15; n = 21). Conclusions: In this multicenter MUE, 26% of all days of anti-MRSA therapy lacked justification; this rate correlated with total facility-specific anti-MRSA DOT. Unnecessary empiric therapy, largely in the ED and for nonpurulent SSTIs and pneumonia without risk factors, was the principal contributor to unjustified DOT.

Funding: None

Disclosures: None

Background: Assessing antimicrobial use (AU) appropriateness isa cornerstone of antimicrobial stewardship, largely accomplished through time-intensive manual chart review of specific agents or diagnoses. Efforts to evaluate appropriateness have focused on assessing the appropriateness of an entire treatment course. An electronic measure was developed to assess the appropriateness of each day of inpatient AU leveraging electronic health record data. Methods: We extracted contextual data, including risk factors for resistant organisms, allergies, constitutional signs and symptoms from diagnostic and procedural codes, and microbiological findings, from the electronic health records of patients in Veterans’ Health Administration inpatient wards reporting data to the National Healthcare Safety Network (NHSN) AU option from 2017–2018. Only the antibacterial categories shown in Figure 1 were included. Respiratory, urinary tract, skin and soft-tissue, and other infection categories were defined and applied to each hospital day. Algorithm rules were constructed to evaluate AU based on the clinical context (eg, in the ICU, during empiric therapy, drug–pathogen match, recommended drugs, and duration). Rules were drawn from available literature, were discussed with experts, and were then refined empirically. Generally, the rules allowed for use of first-line agents unless risk factors or contraindications were identified. AU was categorized as appropriate, inappropriate, or indeterminate for each day, then aggregated into an overall measure of facility-level AU appropriateness. A validation set of 20 charts were randomly selected for manual review. Results: Facility distribution of appropriateness, inappropriateness, and indeterminate AU by 4 of the adult, 2017 baseline NHSN Standardized Antimicrobial Administration Ratio (SAAR) categories are shown in Figure 1. The median facility-level inappropriateness across all SAAR categories was 37.2% (IQR, 29.4%–52.5%). The median facility-level indeterminate AU across all SAAR categories was 14.4% (IQR, 9.1%–21.2%). Chart review of 20 admissions showed agreement with algorithm appropriateness and inappropriateness in 95.4% of 240 antibacterial days.

Conclusions: We developed a comprehensive, flexible electronic tool to evaluate AU appropriateness for combinations of setting, antibacterial agent, syndrome, or time frame of interest (eg, empiric, definitive, or excess duration). Application of our algorithm in 2 years of VA acute-care data suggest substantial interfacility variability; the highest rates of inappropriateness were for anti-MRSA therapy. Our preliminary chart review demonstrated agreement between electronic and manual review in >95% of antimicrobial days. This approach may be useful to identify potential stewardship targets, in the development of decision support systems, and in conjunction with other metrics to track AU over time.

Funding: None

Disclosures: None

A survey of Veterans’ Affairs Medical Centers on control of carbapenem-resistant Enterobacteriaceae (CRE) and carbapenem-producing CRE (CP-CRE) demonstrated that most facilities use VA guidelines but few screen for CRE/CP-CRE colonization regularly or regularly communicate CRE/CP-CRE status at patient transfer. Most respondents were knowledgeable about CRE guidelines but cited lack of adequate resources.

Laboratory identification of carbapenem-resistant Enterobacteriaceae (CRE) is a key step in controlling its spread. Our survey showed that most Veterans Affairs laboratories follow VA guidelines for initial CRE identification, whereas 55.0% use PCR to confirm carbapenemase production. Most respondents were knowledgeable about CRE guidelines. Barriers included staffing, training, and financial resources.