Acknowledgements and Disclosures: This work was supported by the Veterans Affairs (VA) Health Services and Research Merit Award #15-120. The findings and conclusions in this document are those of the authors, who are responsible for its content, and do not necessarily represent the views of the VA or of the United States Government. A.C. has received research funding from Merck, Pfizer, and The Medicines Company. K.L. has received research funding or acted as a scientific advisor for Melinta Therapeutics, Merck (Cubist), Nabriva Therapeutics, Ocean Spray Cranberries Inc., Pfizer, and Tetraphase Pharmaceuticals.

• Long-term care facilities (LTCFs) often encounter barriers when creating antibiograms including:

1) Lack of expertise 2) Accessing culture data 3) Low isolate counts (i.e. n<30)

• LTCFs may utilize antibiograms of affiliate hospitals if they cannot make their own

• Susceptibility rates between LTCFs and affiliate hospitals may be similar, although this may vary by geographic proximity

• In 2017 clinical concordance for E. coli susceptibility among the antibiotics evaluated ranged from 65% to 100%

• There were no statistical differences found when comparing LTCFs on the same campus versus those on remote campuses

• Futures studies and resources are needed to assist LTCFs in developing and implementing antibiograms to further antimicrobial stewardship efforts in these settings

A National Comparison of Antibiograms Between Veterans Affairs Long-Term Care Facilities and Affiliated HospitalsMaria-Stephanie A. Tolg, PharmD1,2; Aisling R. Caffrey, PhD1-3; Haley J. Appaneal, PharmD1-3; Robin L. P. Jump, MD, PhD4,5; Vrishali Lopes, MS1,3;

Stephanie I. Gidmark, MPH1; David M. Dosa, MD, MPH1-3; Kerry L. LaPlante, PharmD, FCCP, FIDSA1-3

1Rhode Island Infectious Diseases Research Program, Providence Veterans Affairs Medical Center, Providence, RI;2Center of Innovation in Long Term Services and Supports, Providence Veterans Affairs Medical Center, Providence, RI; 3College of Pharmacy, University of Rhode Island, Kingston, RI;

4Geriatric Research Education and Clinical Center (GRECC) and the Specialty Care Center of Innovation at the Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio; 5Division of Infectious Diseases and HIV Medicine, Department of Medicine and Department of Population & Quantitative Health Sciences, Case Western Reserve University, Cleveland, Ohio

Conclusions

ResultsAbstract

Background

Numbers in cells are representative of weighted average susceptibility rates; LTCF= long-term care facility; VAMC= Veterans Affairs medical center

Results

Methods

Study Objectives: 1. To compare agreement between Escherichia coli susceptibility rates in

antibiograms of LTCFs and affiliate medical centers2. To review susceptibility agreement based on geographic proximity between the

LTCFs and affiliate medical centers

Background: Long-term care facilities (LTCFs) face several barriers to creating antibiograms. Here, we evaluate if LTCFs can use antibiograms from affiliated hospitals as their own antibiogram.Methods: Facility-specific antibiograms were created for all Veterans Affairs (VA) LTCFs and VA Medical Centers (VAMCs) for 2017. LTCFs and affiliated VAMCs were paired and classified as being on the same campus or geographically distinct campuses based on self-report. For each pair, Escherichia coli susceptibility rates (%S) to cefazolin, ceftriaxone, cefepime, ciprofloxacin, nitrofurantoin, sulfamethoxazole/trimethoprim, ampicillin/sulbactam, piperacillin/tazobactam, and imipenem were compared. As guidelines discourage empiric use of antibiotics if susceptibility rates are <80%, we assessed clinical discordance between each LTCF and affiliated VAMC antibiogram at a threshold of 80% susceptible. The proportions of concordant susceptibilities between LTCFs and VAMCs on the same campus versus geographically distinct campuses were compared using Chi-square tests.Results: A total of 119 LTCFs and their affiliated VAMCs were included in this analysis, with 70.6% (n=84) of facilities located on the same campus and 29.4% (n=35) on geographically distinct campuses. The table below shows the overall clinical concordance (agreement) of LTCFs with their affiliated VAMC in regards to E. coli %S to the compared antibiotics. No significant differences were found when comparing LTCFs on the same campus versus geographically distinct campuses.

Conclusion: Antibiograms between LTCFs and affiliated VAMCs had a high concordance, except for sulfamethoxazole/trimethoprim, cefazolin and ceftriaxone in regards to susceptibility rates of E. coli. Facilities on the same campus were found to have similar concordance rates to geographically distinct facilities. Future studies are needed to investigate how the various approaches to creating LTCF-specific antibiograms are associated with clinical outcomes.

Agreement Rates between LTCFs

and Affiliated VAMCsAntibiotics

90-100%Ampicillin/sulbactam

ImipenemNitrofurantoin

80-89%Cefepime

CiprofloxacinPiperacillin/tazobactam

70-79% Sulfamethoxazole/trimethoprim

60-69%Cefazolin

Ceftriaxone

IDWeek 2018, October 5, 2018; San Francisco, CA.

Table 1. Clinical Agreement Categorization of E. coli Susceptibility Rates

between Affiliate LTCFs and Medical Centers

Both refers to a LTCF and the affiliate medical center; % S= percent susceptibility; LTCF= long-term care facility

Cefa

zoli

n

Ceft

ria

xon

e

Cefe

pim

e

Am

pic

illi

n/

sulb

acta

m

Pip

eracil

lin

/

tazob

acta

m

Nit

rofu

ran

toin

Cip

rofl

oxacin

Su

lfam

eth

oxazole

/

Trim

eth

op

rim

Imip

en

em

LTCF 66 80 89 46 92 94 53 67 100

VAMC 73 84 92 52 95 96 65 71 100

Difference in Weighted Susceptibility Rates

-7 -4 -3 -6 -3 -2 -12 -4 0

Table 2. National 2017 Weighted Antibiogram for VA LTCFs and Medical

Centers: E. coli Susceptibility Rates

• 2017 antibiograms were created for each LTCF and each affiliated Veterans Affairs Medical Center (VAMC), n=119 affiliate facility pairs

1. Creation of Antibiograms1

• Between each LTCF and affiliate VAMC, the % susceptibility rates of E. coli against commonly prescribed antibiotics were categorized as concordant or discordant based on a clinically important cut-off of 80%2,3 (Table 1)

2. Clinical Agreement Categorizations

• For each “bug-drug” combination, the percent of facilities that met the defined clinical concordance were calculated

3. Summary of Percent of Facilities Concordant

• The proportion of facilities meeting clinical concordance on the same campus were compared to those on geographically distinct (remote) campuses using Chi-squares analyses, Bonferroni corrected p-value <0.006 for statistical significance

4. Identify Differences between Same vs. Remote

Campus LTCFs

Table 3. Percent of Facilities with Clinically Concordant E. coli Susceptibility

Concordant Discordant

• Both <80% S • LTCF >80 % S, Medical Center <80% S

• Both >80% S • LTCF <80% S, Medical Center >80% S

AntibioticSame

Campus

Remote

CampusesP-value Total

Imipenem 100% (54/54) 100% (23/23) 0.9504 100% (77/77)

Ampicillin/Sulbactam

90% (65/72) 96% (26/27) 0.6045 92% (91/99)

Nitrofurantoin 91% (67/74) 93% (26/28) >0.9999 91% (93/102)

Cefepime 84% (53/63) 89% (24/27) 0.8184 86% (77/90)

Piperacillin/Tazobactam

83% (66/80) 90% (26/29) 0.557 84% (92/109)

Ciprofloxacin 84% (67/80) 75% (20/28) 0.3068 81% (88/108)

Sulfamethoxazole/Trimethoprim

70% (59/84) 90% (27/30) 0.03089 75% (86/114)

Cefazolin 75% (58/77) 52% (12/23) 0.0335 70% (70/100)

Ceftriaxone 63% (52/82) 71% (20/28) 0.4413 65% (77/90)

References: 1) Clinical and Laboratory Standards Institute (CLSI). Analysis and presentation of cumulative antimicrobial susceptibility test data. 4th ed. Approved guideline M39-A4. Wayne, PA: CLSI, 2014.2) Kalil AC, Metersky ML, Klompas M, et al. Management of Adults With Hospital-acquired and Ventilator-associated Pneumonia: 2016 Clinical Practice Guidelines bythe Infectious Diseases Society of America and the American Thoracic Society. Clin Infect Dis;2016;63:1 -51. 3) Gupta K, Hooton TM, Naber KG, et al. International Clinical Practice Guidelines for the Treatment of Acute Uncomplicated Cystitis and Pyelonephritis in Women: A 2010 Update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases. CID 2011;52(5):e103-e120.