Standardized Antimicrobial Administration Ratio Research Articles

Understanding the Impact of Narrow Spectrum Beta-Lactam Use on Overall and Broad-Spectrum Antimicrobial Utilization in South Carolina

Background: The standardized antimicrobial administration ratio (SAAR) is a metric utilized to measure antimicrobial use within and between hospitals by comparing observed to predicted antimicrobial days of therapy. However, it remains unknown whether narrow-spectrum beta-lactam (NSBL) use adds to overall antimicrobial utilization or substitutes broad-spectrum agents. This muti-hospital cohort study examined the impact of NSBL use on overall antimicrobial utilization and the correlation between the use of NSBL and various broad-spectrum antimicrobial categories in South Carolina (SC) hospitals. Methods: SAARs were collected from all hospitals in SC that reported antimicrobial use (AU) data to the National Healthcare Safety Network (NHSN) between 2017 and 2021. SAARs collected included: overall SAAR, broad-spectrum agents predominantly used for hospital-onset infections (BSHO), broad-spectrum agents predominantly used for community-acquired infections (BSCA), NSBL, and antibacterial agents posing the highest risk for Clostridioides difficile infection (CDI). Category SAARs were combined to include data in both the adult intensive care unit (ICU) and adult wards using the formula: [(total observed antimicrobial days ICU + total observed antimicrobial days ward) / (total predicted antimicrobial days ICU + total predicted antimicrobial days wards)]. Pearson correlation coefficient (r) was used to examine the correlation between various SAARs categories. Results: A total of 38 hospitals in South Carolina reported AU to NHSN at least during one calendar year during the study period. The use of NSBL agents was negatively correlated with the use of BSHO (r = -0.596, p < 0.001), BSCA (r = -0.543, p < 0.001), and high-risk CDI antibiotics (r = -0.601, p < 0.001). Moreover, the use of NSBL agents did not correlate with the overall SAAR (r = 0.008, p = 0.93), whereas the use of BSHO (r = 0.587, p < 0.001), BSCA (r = 0.494, p < 0.001), and high-risk CDI agents (r = 0.464; p < 0.001) positively correlated with the overall SAAR. Conclusion: In South Carolina hospitals, the use of NSBLs does not contribute to additional antibiotic use overall as it seems to replace broad-spectrum antimicrobials in various categories. By de-escalating from broad-spectrum agents to NSBL agents, one can improve antimicrobial use without negatively impacting the overall SAAR. This observation encourages implementation of antimicrobial stewardship interventions that increase utilization of NSBLs, when appropriate, such as de-escalation of antimicrobial therapy among others without concerns for increasing the SAAR for overall antibiotic use.

Hospital-Onset Clostridioides difficile infection in chronic kidney disease patients

Introduction: Hospital-onset Clostridioides difficile infection (HO-CDI), reported as laboratory-identified (LabID) event, is common in patients with chronic kidney disease (CKD), especially those with end-stage renal disease (ESRD), and is associated with prolonged length of hospitalization and more severe disease. CKD patients are at increased of developing CDI due to frequent antimicrobial and healthcare exposures. The objective of this study was to assess recent trends of HO-CDI in patients on a nephrology unit at our academic, tertiary care institution. Methods: Retrospective cross-sectional study of patients with HO-CDI who were hospitalized on a nephrology unit between January 2021 to December 2023. Collected variables included: demographic data, characterization of HO-CDI risk factors, infection and diagnosis (including prior history of CDI, toxin versus nucleic acid amplification test [NAAT] positivity, number of loose stools), CDI rate (defined as CDI count/patient days x1000), standardized antimicrobial administration ratio (SAAR) for high-risk for CDI antimicrobials (defined by the National Healthcare Safety Network), and infection prevention and control (IPC) practices, including hand hygiene audit rates. Results: A total of 30 HO-CDI infections were reported on the nephrology unit [Table], with 8 occurring in 2021, 5 in 2022, and 17 in 2023. The median age of patients was 70.8 (range: 37-96) years, and most patients (57%) were female. The majority of patients were admitted from home (73%), and two patients (7%) had a history of CDI in the last 6 months. Among the CDI cases, 60% were NAAT positive and toxin negative, and only 50% had >3 bowel movements (BM) within 24 hours prior to the positive test. Ten percent received promotility agents prior to testing. Most cases (77%) occurred when other CDI patients were on the unit. Hand hygiene compliance rates averaged 81% over the three-year period [Figure 1A]. Eight-four per cent of patients received antibiotics within 30 days of CDI diagnosis; SAAR was >1 for quarters 2 and 4 in 2022, and quarter 1 in 2023 [Figure 1B]. Conclusion: On our nephrology unit, patients often had < 3 BM within 24 hours of CDI diagnosis, and 60% of cases were toxin-negative, NAAT-positive, suggesting possible C. difficile colonization, rather than true infection. In addition, an elevated SAAR correlated with high CDI rates. Multicomponent interventions may be required to reduce the rates of HO-CDI in CKD patients. Opportunities include emphasis on diagnostic and antimicrobial stewardship, environmental cleaning and adherence to IPC practices, including hand hygiene.

A five-year quasi-experimental study to evaluate the impact of empiric antibiotic order sets on antibiotic use metrics among hospitalized adult patients.

Evaluation of adult antibiotic order sets (AOSs) on antibiotic stewardship metrics has been limited. The primary outcome was to evaluate the standardized antimicrobial administration ratio (SAAR). Secondary outcomes included antibiotic days of therapy (DOT) per 1,000 patient days (PD); selected antibiotic use; AOS utilization; Clostridioides difficile infection (CDI) cases; and clinicians' perceptions of the AOS via a survey following the final study phase. This 5-year, single-center, quasi-experimental study comprised 5 phases from 2017 to 2022 over 10-month periods between August 1 and May 31. The study was conducted in a 752-bed tertiary care, academic medical center. Our institution implemented AOSs in the electronic medical record (EMR) for common infections among hospitalized adults. For the primary outcome, a statistically significant decreases in SAAR were detected from phase 1 to phase 5 (1.0 vs 0.90; P < .001). A statistically significant decreases were detected in DOT per 1,000 PD (4,884 vs 3,939; P = .001), fluoroquinolone orders (407 vs 175; P < .001), carbapenem orders (147 vs 106; P = .024), and clindamycin orders (113 vs 73; P = .01). No statistically significant change in mean vancomycin orders was detected (991 vs 902; P = .221). A statistically significant decrease in CDI cases was also detected (7.8, vs 2.4; P = .002) but may have been attributable to changes in CDI case diagnosis. Clinicians indicated that the AOSs were easy to use overall and that they helped them select the appropriate antibiotics. Implementing AOS into the EMR was associated with a statistically significant reduction in SAAR, antibiotic DOT per 1,000 PD, selected antibiotic orders, and CDI cases.

Application of center for disease control and prevention standardized antimicrobial administration ratio to an Indian hospital.

Rigorous antibiotic stewardship is advised by international societies to combat rising antibiotic resistance. A major component of these programs is the metric used for antibiotic consumption measurement. A method for standardized antimicrobial administration ratio (SAAR) is suggested by the Centre for Disease Control & Prevention-National Healthcare Safety Network (NHSN). We applied the SAAR method to calculate antibiotic consumption in a tertiary care hospital in India. We also validated a limited sampling approach to calculate SAAR. The prospective study was conducted in three medical intensive care units over a period of 12 months. Monthly antibiotic consumption was measured by the hospital electronic records. Limited sampling was performed by weekly bedside review of the antibiotic orders. Formulae for SAAR calculation were derived from the NHSN guide. SAAR obtained by electronic records and limited sampling were compared to validate this approach. SAAR was calculated as >1 for an Indian hospital (1.49 by electronic records and 1.43 by limited sampling approach). The difference between the two ratios was not statistically significant (P = .47). SAAR in our setting is 1.49, which is slightly higher than the NHSN benchmark. Antibiotic usage (AU) risk adjustment based on data from the NHSN might not be adequate for calculating SAAR for Indian hospitals. There is a need to perform AU risk factor analysis for Indian settings for better defining SAAR in Indian context. The limited sampling approach can be adapted for calculation of SAAR in settings with limited resources.

In-person prospective audit and feedback on an oncology ward: development of an immunocompromised antimicrobial stewardship program.

To describe clinical syndromes, opportunities for antimicrobial optimization, and acceptance of recommendations made by an immunocompromised antimicrobial stewardship program performing in-person prospective audit and feedback (IPPAF) on inpatient oncology services. Retrospective cohort study. Three inpatient oncology services including patients with solid tumor malignancies in an academic cancer center. Hospitalized adults with oncologic malignancies receive antimicrobials for any indication. We reviewed all patients receiving antimicrobials on inpatient oncology services who were included in IPPAF and prospectively documented clinical syndromes represented, most common recommendations, and acceptance rate. We also examined the standardized antimicrobial administration ratio (SAAR) for oncology units over the study period. Over 34 weeks, we performed 154 interventions for 138 patients. Metastatic malignancy was common (52%) and 90-day mortality was high (43%). Diagnostic uncertainty was common (33/154, 21%), as were cases of intra-abdominal pathology (30/154, 19%), pneumonia (25/154, 16%), and urinary tract infection (12/154, 8%). The most common recommendations were changes in duration (63/154, 41%) and stopping antimicrobials for syndromes determined to be noninfectious (29/154, 19%). Acceptance of interventions was high (77% overall) and several SAARs on the primary oncology unit significantly decreased after starting IPPAF. We identified numerous opportunities for antimicrobial optimization among solid tumor malignancy patients. Most clinical syndromes were ones also encountered frequently in non-oncology populations, but several were unique and represented opportunities for targeted education.

Comparison of antimicrobial utilization metrics: Food for thought for an antimicrobial stewardship programme

Given the overuse of antimicrobials and increasing antimicrobial resistance, the World Health Organization and Centers for Disease Control and Prevention recommend antimicrobial stewardship programmes to measure and assess the use of antimicrobials. Several antimicrobial use metrics have been described, including days of therapy, defined daily doses and standardized antimicrobial administration ratio. Understanding these metrics, including the advantages and disadvantages, can help antimicrobial stewardship programmes to monitor antimicrobial use at their institution, and assess the impact of antimicrobial stewardship efforts. This review discusses the three commonly used antimicrobial use metrics, their pros and cons, and how antimicrobial stewardship programmes can use these metrics to help assess the use of antimicrobials.

Show me the data: A statewide comparative report of National Healthcare Safety Network (NHSN) Antimicrobial Use Option standardized antimicrobial administration ratios (SAARs).

The Antimicrobial Stewardship Collaborative of South Carolina created quarterly Comparative SAAR Analysis Reports based on standardized antimicrobial administration ratio (SAAR) data from the NHSN Antimicrobial Use (AU) Option. These reports provide SAAR histograms and site-specific feedback to participating facilities in South Carolina. They were created to improve antimicrobial use throughout the state, especially in rural regions.

155. Antimicrobial Resistance Patters as a Predictor of Standardized Antimicrobial Administration Ratio: A National Correlation Study

BackgroundData on antimicrobial usage (AU) and antimicrobial resistance (AR) is submitted to the National Healthcare Safety Network (NHSN) from facilities monthly. Bacterial proportion resistant (%R) from the AR option reports proportion of isolates resistant to specific antimicrobial categories. Standardized Antimicrobial Administration Ratio (SAAR), generated under the AU option, compares observed to predicted days of antimicrobial therapy. The purpose of this study was to evaluate the association between %R and SAAR for broad-spectrum antibacterial agents predominantly used for hospital-onset infections (BSHO) and antibacterial agents predominantly used for resistant gram-positive infections (gram-pos) in adult intensive care units (ICUs) and medical-surgical wards (M/S).MethodsThis retrospective observational review utilized data reported to NHSN to examine the association of BSHO and gram-pos SAARs with %R for various phenotypic categories by quarter from 2017 through the second quarter of 2020. Phenotypic categories included methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecalis and faecium (VRE), extended-spectrum cephalosporin-resistant Escherichia coli and Klebsiella spp. (ESBL), and multi-drug resistant Pseudomonas aeruginosa (MDR PSA). Pearson correlations were used to quantify the associations between SAARs and %R.ResultsA total of 182 institutions were included for analysis. Weak, positive correlations were observed between SAAR for BSHO in ICU and M/S for MDR PSA %R and also for ESBL %R (r = 0.14 to 0.22, all p < 0.0001). For the gram-pos SAAR in ICU and M/S, there were weak positive correlations between MRSA %R and VRE %R (r = 0.20 to 0.31, all p < 0.0001).ConclusionSAARs are multifactorial, yet these results highlight that more resistant organisms may possibly be contributing to higher use of antimicrobials for facilities. Future SAAR calculations could consider incorporating resistance trends from %R within the institution for increases in AU and adjusting SAARs accordingly. Comprehension of the relationship between %R and SAAR can aid facilities with stewardship programs and understanding how resistance contributes to antibiotic usage.Disclosures Julia Moody, MS, Medline (Other Financial or Material Support, Conducted studies in which participating hospitals received contributed antiseptic product)Molnlycke (Other Financial or Material Support, Conducted studies in which participating hospitals received contributed antiseptic product)

753. Impact of COVID-19 on Healthcare Facility-Onset Clostridiodes difficile Infection

BackgroundIt is estimated that the majority of hospitalized COVID-19 patients around the world received antibiotics despite the fact that bacterial co-infections are rare. This can lead to increased antimicrobial resistance and Clostridioides difficile infections (CDI). Gastrointestinal symptoms of COVID-19 may also contribute to increased testing. The objective of this study was to assess the impact of the COVID-19 pandemic on our healthcare facility-onset (HO) CDI rates.MethodsThis was a retrospective cross-sectional study comparing CDI rate per 1,000 patient days, C. diff order rate per 1,000 patient days, Standardized Antimicrobial Administration Ratio (SAAR), and Standardized Infection Ratio (SIR) in the pre-COVID-19 period from January 1, 2019 to December 31, 2019 to the COVID-19 period from April 1, 2020 to March 31, 2021 at a 877-bed tertiary care hospital in Detroit, Michigan. CDI and order rates were extracted from the electronic medical record (Epic™ Bugsy). SAAR and SIR data were extracted from National Healthcare Safety Network (NHSN).ResultsThe average CDI rate per 1,000 patient days was 4.29 pre-COVID-19 compared to 1.98 during COVID-19 with a 54% reduction, and the C. diff order rate per 1,000 patient days also decreased from 130.89 to 93.03, resulting in a 29% reduction (Figure 1). The SIR was 0.383 compared to 0.308 during COVID-19 (P-value 0.404). SAAR decreased from 1.095 to 0.945 (P-value < 0.001). However, our institution experienced three COVID-19 waves, with peaks in April 2020, November 2020 and March 2021, that correlated with high risk CDI antibiotic utilization in intensive care unit (ICU) (Figure 2). The average hand hygiene rate increased from 82% to 92%. Figure 1. Clostridioides difficile order and infection rates pre-and during COVID-19 pandemic. Figure 2. Standardized Antimicrobial Administration Ratio (SAAR) pre-and during COVID-19 pandemic.ConclusionDespite the COVID-19 pandemic, the HO-CDI and C. diff order rates and overall SAAR decreased; however, antibiotic utilization increased in the ICU during the COVID-19 waves. The overall decrease may be multifactorial and related to increased hand hygiene compliance, isolation and personal protective equipment use and overall decreased antibiotic use and C. diff orders.Disclosures Rachel Kenney, PharmD, Medtronic, Inc. (Other Financial or Material Support, spouse is an employee and shareholder)

114. Optimization of Inpatient Antibiotic Use via an Electronic Antimicrobial Stewardship Module and an Infectious Diseases Pharmacy Resident

BackgroundAntibiotic resistance is a public health crisis and antimicrobial stewardship (AMS) pharmacists serve a crucial role in preventing inappropriate use. At Montefiore Medical Center (1,500-bed hospital), a new electronic medical record AMS module was implemented with assistance from an infectious diseases (ID) pharmacy resident in October 2020. The module utilizes a dynamic scoring system to assist in prioritizing interventions, including bug-drug mismatches, insufficient coverage, or de-escalation. The AMS module is operationalized by ID pharmacists during the week and an ID pharmacy resident every other weekend. The objective of this study was to assess the impact of an ID pharmacy resident performing AMS module interventions on broad spectrum antibiotic use.MethodsAn observational study of AMS module interventions on antibiotic use (AU) in days of therapy per 1,000 days present and standardized antimicrobial administration ratio (SAAR) was performed. AU data for piperacillin-tazobactam (P/T) and SAAR prior to (October 2019– December 2019) and after (October 2020 – December 2020) the integration of an ID pharmacy resident and the AMS module was compared. Additional data collected included total number and type of interventions.ResultsA total of 539 interventions were made by AMS pharmacists and 36.5% of these were completed by the ID pharmacy resident. Across 6 different units, there was a statistically significant decrease in the SAAR for broad spectrum antibacterial agents (Figure 1), and a decrease of at least 10% in P/T use during the two different time periods (Table 1). An estimated P/T cost reduction of 26% of (&48,708 to &36,235.80) was observed. AMS pharmacists made 63 interventions in respective units. The top three intervention types were dose/frequency/duration recommendations, pharmacokinetic vancomycin dosing/monitoring, and de-escalation. The acceptance rate of interventions was 99% (534 accepted interventions/539 total interventions).Figure 1. SAAR Comparison of Broad-Spectrum Agents Table 1. AU Rate of Piperacillin-tazobactam ConclusionOverall, there was a statistically significant impact on SAARs and a >10% change in P/T AU rate with an estimated cost reduction >25% on select units after implementation of the AMS module with an ID pharmacy resident.Disclosures Kelsie Cowman, MPH, Merck (Research Grant or Support) Priya Nori, MD, Merck (Grant/Research Support) Priya Nori, MD, Nothing to disclose Yi Guo, PharmD, BCIDP, Merck (Research Grant or Support)

39. Impact of Antimicrobial Stewardship Interventions in a Community Hospital setting: An Interrupted Times Analysis

Abstract Background Community hospitals have fewer resources for antimicrobial stewardship programs (ASP) compared to larger tertiary hospitals. At our 312-bed community hospital, Long Island Jewish Forest Hills/Northwell, a combination of modified preauthorization, prospective audit feedback, and ASP education was implemented starting in August 2019 (Monday through Friday 9 am to 5 pm). Methods This retrospective study evaluated the impact of ASP interventions on the rate of targeted antimicrobial use over a 7 month pre- vs 7 month post- intervention period (Aug 2018 to Feb 2019 vs Aug 2019 to Feb 2020). Targeted antimicrobials included piperacillin-tazobactam, vancomycin, daptomycin, and carbapenems. The primary outcome was the monthly mean for overall targeted antimicrobial use measured by the rate of antimicrobial days per 1000 days present. Secondary outcomes were the individual rates of antimicrobial days per 1000 days present for each of the targeted antimicrobials, and the hospital’s overall standardized antimicrobial administration ratio (SAAR). Data were analyzed as a segmented regression of interrupted time series. Results Pre-intervention, there was an increasing trend (positive slope, p&amp;lt; 0.05) in the monthly mean, hospital SAAR, vancomycin and piperacillin-tazobactam use. Post-intervention, there was a significant change in slope for these same metrics, indicating a decrease in the mean use. Immediate impact of ASP interventions, measured by the difference in antibiotic use between the end of each intervention period, was visually evident in all cases except carbapenems (Fig. 1 through 4). The immediate impact on the overall monthly mean represented a significant reduction in the rate of antimicrobial days per 1000 days present, -12.72 (CI -21.02 to -4.42, P &amp;lt; 0.0066). The pre- vs post- ASP gap for all measures was negative and consistent with fewer days of antibiotic use immediately following intervention. Conclusion A targeted, multifaceted ASP intervention utilizing modified preauthorization, prospective audit feedback, and education significantly reduced antibiotic use in a community hospital. Disclosures All Authors: No reported disclosures

Application of Standardized Antimicrobial Administration Ratio as a Motivational Tool within a Multi-Hospital Healthcare System.

The standardized antimicrobial administration ratio (SAAR) is a novel antimicrobial stewardship metric that compares actual to expected antimicrobial use (AU). This prospective cohort study examines the utility of SAAR reporting and inter-facility comparisons as a motivational tool to improve overall and broad-spectrum AU within a three-hospital healthcare system. Transparent inter-facility comparisons were deployed during system-wide antimicrobial stewardship meetings beginning in October 2017. Stakeholders were advised to interpret the results to foster competition and incorporate SAAR data into focused antimicrobial stewardship interventions. Student’s t-test was used to compare mean SAARs in the pre- (July 2017 through October 2017) and post-intervention periods (November 2017 through June 2019). The mean pre-intervention SAARs for hospitals A, B, and C were 0.69, 1.09, and 0.60, respectively. Hospital B experienced significant reductions in SAAR for overall AU (from 1.09 to 0.83; p < 0.001), broad-spectrum antimicrobials used for hospital-onset infections (from 1.36 to 0.81; p < 0.001), and agents used for resistant gram-positive infections in the intensive care units (from 1.27 to 0.72; p < 0.001) after the interventions. The alignment of the SAAR across the health-system and sustained reduction in overall and broad-spectrum AU through implementation of inter-facility comparisons demonstrate the utility in the motivational application of this antimicrobial use metric.

1676. Evaluation of Antibiotic Overuse for Asymptomatic Bacteriuria in a Hospital with Low Baseline Antibiotic Use

BackgroundIn 2019, the Infectious Diseases Society of America published guidelines for the management of asymptomatic bacteriuria (ASB) with recommendations to avoid antimicrobial therapy in most patients. Denver Health has existing guidance for the management of patients with a urinary tract infection (UTI) and in August of 2019, implemented specific guidance for the management of ASB. As an institution, Denver Health has a Standardized Antimicrobial Administration Ratio (SAAR) of 0.8-0.9, suggesting a strong antimicrobial stewardship program with a ratio of < 1. The purpose of this study is to assess if signs and symptoms were present in patients prescribed an antibiotic for UTI.MethodsWe retrospectively identified hospitalized patients at least 18 years old who were prescribed an antibiotic with “UTI” as the indication from March 1st to August 31st, 2019. Patients with catheter-associated UTIs were excluded. A random sample of 50 cases was manually reviewed for signs and symptoms of infection. Signs were considered fever, defined as at least 38oC or leukocytosis, defined as at least 10 k/uL WBC. Symptoms collected were based on documentation of patient reported dysuria, frequency, or urgency, or findings of hematuria. The primary outcome was proportion of patients prescribed an antibiotic for UTI in the absence of signs or symptoms. Prescribing patterns for choice and duration of antimicrobials were also surveyed.ResultsA total of 382 antibiotics were prescribed for UTI during the study period. Of the 50 cases reviewed, median age was 65.8 years, with 11% being male. Overall, 29 patients (58%) had no documented symptoms while being treated for UTI. Additionally, 22 patients (44%) had no documented fever, leukocytosis, or urinary symptoms. The most commonly prescribed antibiotics were cefdinir, fosfomycin, and nitrofurantoin. Tables 1 and 2 include additional findings.Table 1 Symptomology and Type of UTI Table 2 Antimicrobial Choice and Duration ConclusionDespite a well established stewardship program, nearly half of patients prescribed an antibiotic for UTI did not have signs or symptoms consistent with infection. This suggests many patients were treated for ASB, without necessity. Among hospitals with comparatively low antibiotic use, ASB may be a high-yield opportunity to reduce unnecessary antibiotic use.Disclosures All Authors: No reported disclosures

209. Antibiotic Utilization During the COVID-19 Surge in Detroit

BackgroundAntibiotic overutilization during the COVID-19 pandemic has been reported, despite relatively infrequent bacterial co-infection. We explored antibiotic utilization before, during and after the COVID-19 surge in Michigan.MethodsCross-sectional study at an 877-bed hospital in Detroit, Michigan from January 2019 through May 2020. Measures: Count of COVID-19 hospital admissions by day. Monthly antibiotic utilization for formulary agents used to treat pneumonia were measured using monthly days of therapy (DOT) per 1000 patient days present and the National Health Care Safety Network Standardized Antimicrobial Administration Ratio (SAAR). Descriptive analysis was utilized.ResultsThe first COVID-19 case was detected March 11, 2020 and peaked in early April (Figure 1). Antibiotic utilization is demonstrated in Figure 2. The COVID-19 peak was associated with increased use of multiple antibiotics; notably, DOT per 1000 days present for ceftriaxone, cefepime and doxycycline were 85.43, 79.42 and 71.56, respectively in April. The institutional all-antibacterial SAAR was significantly reduced in May at 0.96, p=0.0022, after the COVID-19 surge.Figure 1 Figure 2 ConclusionWe observed increased utilization of multiple antibiotics during the COVID-19 surge, and reduction in the all-antibacterial SAAR after the surge. More robust information is needed to promote optimal antibiotic use for patients with COVID-19 infections.Disclosures All Authors: No reported disclosures

Standardized Antimicrobial Administration Ratio (SAAR) Clinical Outcomes Assessment in a Large Community Healthcare System

Background: Research on the association between the standardized antimicrobial administration ratio (SAAR) and clinical outcomes is lacking. Objective: We compared SAAR and patient outcomes in 97 acute-care facilities affiliated with a large healthcare system. Methods: Facilities were classified using the broad-spectrum hospital-onset (BSHO) SAAR for medical, surgical, and medical-surgical wards as low, moderate, or high antimicrobial use: low use SAAR, &lt;0.8; moderate use SAAR, 0.95–1.05; and high-use SAAR, &gt;1.2. Data were included from patients aged ≥18 years who were discharged between the first quarter of 2018 and the second quarter of 2019, had nonmissing matching criteria, BMI between 10 and 90, and at least 1 BSHO medication administered in a medical, surgical, or medical-surgical ward. Patients were matched for gender, age group, BMI category, year and quarter of discharge, ICU stay, and diagnosis-related group (DRG). Eligible drugs included all routes for cefepime, ceftazidime, doripenem, imipenem/cilastatin, meropenem, and piperacillin/tazobactam and IV only for amikacin, aztreonam, gentamicin, and tobramycin. Outcomes were evaluated in a pairwise manner using t tests or χ2 tests. Results: Each of the 3 study groups consisted of 6,327 patients, 51% of whom were men; average age, 63 years; 70% of whom were obese or overweight, and 19% of whom had an ICU stay. The most common DRG code was infectious and parasitic diseases (57%) followed by digestive system (9%), respiratory system (7%), and kidney and urinary tract (6%). High antibiotic use was associated with longer length of stay and a higher estimated cost per visit. Low antibiotic use was associated with higher rate of mortality and a lower rate of readmissions compared to moderate use. The low-usage group did not exhibit a statistically significant difference in mortality, readmissions, or rate of C. difficile compared to the high-usage group. Conclusions: The optimal antibiotic utilization group varied among outcomes. Further evaluation of outcomes is needed for the SAAR to understand the ranges and the relationship between the measure and clinical outcomes.Funding: NoneDisclosures: None

Increasing Voluntary Public Health Reporting to the NHSN Antimicrobial Use Option

Background: The CDC NHSN launched the Antimicrobial Use Option in 2011. The Antimicrobial Use Option allows users to implement risk-adjusted antimicrobial use benchmarking within- and between- facilities using the standardized antimicrobial administration ratio (SAAR) and to evaluate use over time. The SAAR can be used for public health surveillance and to guide an organization’s stewardship or quality improvement efforts. Methods: Antimicrobial Use Option enrollment grew through partner engagement, targeted education, and development of data benchmarking. We analyze enrollment over time and discuss key drivers of participation. Results: Initial 2011 Antimicrobial Use Option enrollment efforts awarded grant Funding: to 4 health departments. These health departments partnered with hospitals, which encouraged vendors to build infrastructure for electronic antimicrobial use reporting. CDC supported vendors through outreach and education. In 2012, with CDC support, Veterans’ Affairs (VA) Informatics, Decision-Enhancement, and Analytic Sciences Center and partners began implementation of Antimicrobial Use Option reporting and validation of submitted data. These early efforts led to enrollment of 64 facilities by 2014 (Fig. 1). As awareness of the antimicrobial use option grew, we focused on facility engagement and development of benchmark metrics. A second round of grant Funding: in 2015 supported submission to the Antimicrobial Use Option from additional facilities by Funding: a vendor, a healthcare system, and an antimicrobial stewardship network. In 2015, CMS recognized the Antimicrobial Use Option as a choice for public health registry reporting under Meaningful Use Stage 3, resulting in an increase in participating hospitals. Antimicrobial Use Option enrollment increased in 2015 (n = 120), coinciding with national prioritization of antimicrobial stewardship. In 2016, the SAAR, was released in NHSN. We leveraged the SAAR to encourage participation from additional facilities and began quarterly calls to encourage continued participation from existing users. In 2016, the Department of Defense began submitting data to the Antimicrobial Use Option, resulting in 207 facilities enrolled in 2016, which grew to 616 in 2017. As of November 2019, 12 vendors self-report submission capabilities and 1,470 facilities, of ~6,800 active NHSN participants, are enrolled in the Antimicrobial Use Option. Two states have passed requirements regulating Antimicrobial Use Option reporting with Tennessee’s requirement going into effect in 2021. Conclusions: The Antimicrobial Use Option offers evidence that collaboration with partners, and leveraging of benchmarking metrics available to a national surveillance system can lead to increased voluntary participation in surveillance of high-priority public health data. Moving forward, we will continue expanding analytic capabilities and partner engagement.Funding: NoneDisclosures: None

Development of an Electronic Tool to Measure Daily Appropriateness of Inpatient Antibacterial Use

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 &gt;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: NoneDisclosures: None

Appropriateness of Anti-MRSA Therapy in Hospitalized Patients With Suspected Community-Onset Infections

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 &gt;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: NoneDisclosures: None

Hospital Microbiologic Culture Results to Predict the Use of Anti–methicillin-Resistant Staphylococcus aureus (MRSA)

Background: To provide a standardized, risk-adjusted method for summarizing antimicrobial use (AU), the Centers for Disease Control and Prevention developed the standardized antimicrobial administration ratio, an observed-to-predicted use ratio in which predicted use is estimated from a statistical model accounting for patient locations and hospital characteristics. The infection burden, which could drive AU, was not available for assessment. To inform AU risk adjustment, we evaluated the relationship between the burden of drug-resistant gram-positive infections and the use of anti-MRSA agents. Methods: We analyzed data from acute-care hospitals that reported ≥10 months of hospital-wide AU and microbiologic data to the National Healthcare Safety Network (NHSN) from January 2018 through June 2019. Hospital infection burden was estimated using the prevalence of deduplicated positive cultures per 1,000 admissions. Eligible cultures included blood and lower respiratory specimens that yielded oxacillin/cefoxitin–resistant Staphylococcus aureus (SA) and ampicillin-nonsusceptible enterococci, and cerebrospinal fluid that yielded SA. The anti-MRSA use rate is the total antimicrobial days of ceftaroline, dalbavancin, daptomycin, linezolid, oritavancin, quinupristin/dalfopristin, tedizolid, telavancin, and intravenous vancomycin per 1,000 days patients were present. AU rates were modeled using negative binomial regression assessing its association with infection burden and hospital characteristics. Results: Among 182 hospitals, the median (interquartile range, IQR) of anti-MRSA use rate was 86.3 (59.9–105.0), and the median (IQR) prevalence of drug-resistant gram-positive infections was 3.4 (2.1–4.8). Higher prevalence of drug-resistant gram-positive infections was associated with higher use of anti-MRSA agents after adjusting for facility type and percentage of beds in intensive care units (Table 1). Number of hospital beds, average length of stay, and medical school affiliation were nonsignificant. Conclusions: Prevalence of drug-resistant gram-positive infections was independently associated with the use of anti-MRSA agents. Infection burden should be used for risk adjustment in predicting the use of anti-MRSA agents. To make this possible, we recommend that hospitals reporting to NHSN’s AU Option also report microbiologic culture results.Funding: NoneDisclosures: None

National Healthcare Safety Network Standardized Antimicrobial Administration Ratios (SAARs): A Progress Report and Risk Modeling Update Using 2017 Data.

The Standardized Antimicrobial Administration Ratio (SAAR) is a risk-adjusted metric of antimicrobial use (AU) developed by the Centers for Disease Control and Prevention (CDC) in 2015 as a tool for hospital antimicrobial stewardship programs (ASPs) to track and compare AU with a national benchmark. In 2018, CDC updated the SAAR by expanding the locations and antimicrobial categories for which SAARs can be calculated and by modeling adult and pediatric locations separately. We identified eligible patient-care locations and defined SAAR antimicrobial categories. Predictive models were developed for eligible adult and pediatric patient-care locations using negative binomial regression applied to nationally aggregated AU data from locations reporting ≥9 months of 2017 data to the National Healthcare Safety Network (NHSN). 2017 Baseline SAAR models were developed for 7 adult and 8 pediatric SAAR antimicrobial categories using data reported from 2156 adult and 170 pediatric locations across 457 hospitals. The inclusion of step-down units and general hematology-oncology units in adult 2017 baseline SAAR models and the addition of SAARs for narrow-spectrum B-lactam agents, antifungals predominantly used for invasive candidiasis, antibacterial agents posing the highest risk for Clostridioides difficile infection, and azithromycin (pediatrics only) expand the role SAARs can play in ASP efforts. Final risk-adjusted models are used to calculate predicted antimicrobial days, the denominator of the SAAR, for 40 SAAR types displayed in NHSN. SAARs can be used as a metric to prompt investigation into potential overuse or underuse of antimicrobials and to evaluate the effectiveness of ASP interventions.