289. International Validation of a Methicillin-Resistant Staphylococcus aureus (MRSA) Risk Assessment Tool for Acute Bacterial Skin and Skin Structure Infections (ABSSSI)
Session: Poster Abstract Session: Bone and Joint Infections
Thursday, October 4, 2018
Room: S Poster Hall

Background: Anti-MRSA antibiotic under- and overprescribing for ABSSSI is common. To address this, we previously developed an MRSA risk assessment tool using prior literature and patient data from a single health system in Detroit, Michigan, USA. The objective of this study was to validate this risk assessment tool internationally.

Methods: Multicenter, international, prospective cohort study. Inclusion: age ≥ 18 y; purulent ABSSSI from 07/2016 - 03/2018. Exclusion: no culture; osteoarticular infection; bite wounds; odontogenic infections. Patient MRSA risk scores were computed using the following criteria (point value): previous MRSA infection/colonization (2); previous hospitalization (1); previous antibiotics (1); chronic kidney disease (1); intravenous drug use (1); HIV/AIDS (1); diabetes with obesity (1). The likelihood ratio of each patient’s score was used to convert local surveillance MRSA percentage (prior probability) into an individual patient estimated MRSA probability (posterior probability). The predictive performance of local surveillance MRSA percentage, MRSA risk score, and estimated MRSA probability were quantified using the area under the Receiver Operating Characteristic curve (aROC) and compared using the Hanley and McNeil method.

Results: 203 patients from 7 international sites included. The most common infection types were wound (28.6%), abscess (25.1%), and cellulitis with abscess (20.7%). MRSA was observed in 33% of patients and ranged from 10% in Beijing, CN to 58.8% in Mexico City, MX. MRSA was significantly more prevalent among patients with higher MRSA risk scores (figure 1). The MRSA risk score aROC (95%CI) [0.748 (0.678 – 0.819)] was significantly greater than local surveillance MRSA percentage [0.646 (0.569 – 0.722)] (P = .016). The estimated MRSA probability aROC [0.781 (0.716 – 0.845)] was significantly greater than local surveillance MRSA percentage (P < .001) but not the MRSA risk score (P = .192).

Conclusion: The MRSA risk score and estimated MRSA probability were significantly more predictive of MRSA ABSSSI compared to local MRSA surveillance percentage. Further study, including potential impact of this MRSA risk assessment tool on prescribing patterns are required before widespread application.

 

Evan J. Zasowski, PharmD, MPH1,2, Trang D. Trinh, PharmD, MPH1,3, Kimberly Claeys, PharmD, BCPS1,4, Matthew Dryden, MD, FRCPath, FRCPS5, Sergey Shlyapnikov, MD6, Matteo Bassetti, MD, PhD7, Alessia Carnelutti, MD7, Nana Khachatryan, MD8, Asok Kurup, MBBS, MMED9, Abraham Pulido Cejudo, MD10, Luiz Henrique Melo, MD11, Bin Cao, MD12 and Michael J. Rybak, PharmD, MPH, PhD13, (1)Anti-Infective Research Laboratory, Department of Pharmacy Practice, Wayne State University, Eugene Applebaum College of Pharmacy & Health Sciences, Detroit, MI, (2)Department of Pharmacy Practice and Translational Research, University of Houston College of Pharmacy, Houston, TX, (3)Department of Clinical Pharmacy, University of California, San Francisco, School of Pharmacy, San Francisco, CA, (4)Pharmacy Practice and Science, University of Maryland School of Pharmacy, Baltimore, MD, (5)Royal Hampshire County Hospital, Winchester, United Kingdom, (6)Research Institute for Emergency Care, Saint Petersburg, Russian Federation, (7)Santa Maria Misericordia Hospital, Udine, Italy, (8)Department of Surgery and Clinical Angiology, Moscow State University of Medicine and Dentistry of Federal Agency for Healthcare and Social Development, Moscow, Russian Federation, (9)Mount Elizabeth Hospital, Singapore, Singapore, (10)General Hospital of Mexico, Mexico City, Mexico, (11)Hospital Dona Helena, Joinville, Brazil, (12)Department of Respiratory and Critical Care Medicine, China-Japan Friendship hospital, Beijing, China, (13)Anti-Infective Research Laboratory, College of Pharmacy, School of Medicine, Division of Infectious Diseases, Wayne State University, Detroit, MI

Disclosures:

E. J. Zasowski, None

T. D. Trinh, None

K. Claeys, Nabriva: Scientific Advisor , Consulting fee . Melinta: Scientific Advisor , Consulting fee .

M. Dryden, Motif BioSciences: Board Member , Consulting fee .

S. Shlyapnikov, None

M. Bassetti, None

A. Carnelutti, None

N. Khachatryan, None

A. Kurup, None

A. Pulido Cejudo, None

L. H. Melo, None

B. Cao, None

M. J. Rybak, Allergan: Consultant , Grant Investigator and Speaker's Bureau , Research grant and Research support . Achaogen: Consultant , Grant Investigator and Speaker's Bureau , Consulting fee , Research grant and Research support . Bayer: Consultant , Grant Investigator and Speaker's Bureau , Consulting fee , Research grant and Research support . Melinta: Consultant , Grant Investigator and Speaker's Bureau , Consulting fee , Research grant and Research support . Merck: Consultant , Grant Investigator and Speaker's Bureau , Consulting fee , Research grant and Research support . Theravance: Consultant , Grant Investigator and Speaker's Bureau , Consulting fee , Research grant and Research support . Sunovian: Consultant , Grant Investigator and Speaker's Bureau , Consulting fee , Research grant and Research support . Zavante: Consultant , Grant Investigator and Speaker's Bureau , Consulting fee , Research grant and Research support . NIAID: Consultant , Grant Investigator and Speaker's Bureau , Consulting fee , Research grant and Research support .

Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 3rd with the exception of research findings presented at the IDWeek press conferences.