909. Antimicrobial Prescriptions for Veterans Affairs (VA) Influenza-Coded Encounters and Patients Tested for Influenza
Session: Poster Abstract Session: Respiratory Infections
Friday, October 4, 2013
Room: The Moscone Center: Poster Hall C
Background: Antimicrobial (AM) prescriptions are a data source available to VA’s biosurveillance program.  Previously, we found that VA’s antibacterial (AB) usage correlated better with influenza-like illness (ILI) encounters than antiviral (AV) prescriptions.  We investigated influenza-coded encounters and influenza tested patients to determine utilization of AMs.

Methods: AV (oseltamivir, zanamivir) and AB (azithromycin, moxifloxacin, amoxicillin/clavulanate) outpatient (OP) prescriptions were extracted for 129 VA medical centers and associated OP clinics using VA Corporate Data Warehouse for 3 influenza seasons (October 1, 2010-March 31, 2013).  Additionally, OP influenza ICD-9-CM coded encounters and influenza test results were extracted from VA’s Healthcare Associated Infection and Influenza Surveillance System (HAIISS).  Duplicate encounters and tests within a 30 day window were removed and matched with AMs given to the same patient within 30 days of encounter or test date.  

Results: There were 19,409 influenza-coded encounters among 19,240 patients, and 54,922 influenza tests done among 53,359 patients tested for influenza.  Among influenza-coded encounters, 5,421 (28%) had influenza testing done, 4,065 (21%) were positive.  Among patients with influenza-coded encounters or positive influenza tests 7,376 (38%) and 4,199 (57%) received an AV and 4533 (23%) and 2152 (29%) received an AB agent, respectively.  Among patients with influenza-coded encounters and positive influenza tests receiving an AB, 2,859 (15%) and 1,256 (17%) received azithromycin, 1,032 (5%) and 639 (9%) received moxifloxacin, and 911 (5%) and 409 (6%) received amoxicillin/clavulanate, respectively.  1,904 patients (10%) with influenza-coded encounters and 1,253 (17%) with positive influenza tests received both an AV and AB.

Conclusion: In contrast to ILI, patients with influenza-coded encounters and positive influenza tests were more likely to receive AV than AB agents.  However, about 50% of patients with influenza actually received AVs and approximately 25% of patients still received an AB.  Our findings suggest a potential target for antimicrobial stewardship, where with increased influenza testing, AB use may be decreased and AV treatment improved.

Patricia Schirmer, MD1, Russell Ryono, Pharm. D.1, Cynthia Lucero-Obusan, MD1, Renee-Claude Mercier, Pharm.D.1,2, Carla Winston, PhD1, Gina Oda, MS1 and Mark Holodniy, MD1,3, (1)Office of Public Health Surveillance and Research, Department of Veterans Affairs, Palo Alto, CA, (2)College of Pharmacy, University of New Mexico, Albuquerque, NM, (3)Stanford University, Palo Alto, CA


P. Schirmer, None

R. Ryono, None

C. Lucero-Obusan, None

R. C. Mercier, None

C. Winston, None

G. Oda, None

M. Holodniy, None

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