1799. Prevalence of Documented Beta-lactam Allergies in the Veterans Affairs Health System from 2000 - 2014. 
Session: Poster Abstract Session: Antibacterial Safety
Saturday, October 29, 2016
Room: Poster Hall
Background: Beta-lactam allergies impact patient care by driving use of less effective and/or safe alternatives. There is limited national data on the prevalence of beta-lactam allergies. Our primary objective was to determine the prevalence of beta-lactam antimicrobial allergies among Veteran Affairs (VA) inpatients.

Methods: This study was a retrospective cohort of all inpatients in the VA health system from 2000-2014 extracted from the VA Corporate Data Warehouse. Allergy histories documented prior to or on admission were linked with inpatient records, aggregated and reported as percent of admissions.

Results: We included 2.9 million patients with 10.9 million admissions in 127 VA facilities. Patients were 95.2% male, with a mean age of 63.3 ± 14.1 years. The most commonly reported beta-lactam allergy on admission was penicillin (n=1,411,074, 13%). Other beta-lactam allergies were far less common including cephalosporins (n=47,321, 0.4%), carbapenems (n=4,598, <0.1%) and aztreonam (n=1496, <0.1%). Results summarized in Table 1. Among cephalosporin and carbapenem allergic patients, n=19,717 (42%) and n=1,788 (39%) also had a penicillin allergy respectively.

Conclusion: Penicillin is the most common beta-lactam allergy present in ~13% of VA hospital admissions. Cephalosporin and carbapenem allergies are less common overall but many patients were documented as dual allergic to penicillin, which limits therapeutic options for them.

Table 1. Change in allergies to beta-lactam antimicrobials between 2000 to 2014

Allergy

2000-2014

(n=10,858,409)

Any Beta-Lactam

1,441,648 (13.3)

0.49

Any Penicillin

1,411,074 (13.0)

0.38

Ampicillin

37,231 (2.6)

-0.03

Piperacillin

17,942 (1.3)

0.25

Any Cephalosporin

47,321 (0.4)

0.10

Cefazolin

15,351 (0.1)

0.02

Ceftriaxone

13,136 (0.1)

0.11

Cefepime

3,710 (0.0)

0.05

Ceftaroline

71 (0.0)

0.01

Any Carbapenem

4,598 (0.0)

0.04

Imipenem

2,917 (0.0)

0.01

Meropenem

618 (0.0)

0.01

Doripenem

33 (0.0)

0.00

Ertapenem

1,056 (0.0)

0.02

Aztreonam

1,496 (0.0)

0.00

Description. The no. (%) of admissions where the patient was

allergic to a commonly utilized inpatient beta-lactam antimicrobial.

%Δ – percentage point change from 2000 to 2014.

Kevin Mcconeghy, Pharm.D.1, Haley Morrill, PharmD2, Aisling Caffrey, PhD, MS3, Amal N. Trivedi, MD4, David Dosa, MD, MPH5 and Kerry Laplante, Pharm.D., FCCP2, (1)Research, Providence VA Medical Center, Providence, RI, (2)Providence Veterans Affairs Medical Center, Providence, RI, (3)University of Rhode Island, Kingston, RI, (4)Research, COIN-LTSS, Providence Veterans Affairs Medical Center, Providence, RI, (5)Brown University, Providence, RI

Disclosures:

K. Mcconeghy, None

H. Morrill, None

A. Caffrey, Pfizer: Research , Research grant
Merck (Cubist): Research , Research grant

A. N. Trivedi, None

D. Dosa, None

K. Laplante, Merck (Cubist): Consultant and Scientific Advisor , Research support
Pfizer: Consultant and Scientific Advisor , Research support
Allergan (Forest): Consultant and Scientific Advisor , Research support
The Medicines Company: Consultant and Scientific Advisor , Research support
Melinta: Consultant and Scientific Advisor , Research support

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