Att G.1_Antimicrobial Use & Resistance

Antimicrobial Use and Resistance Module
AUR

Antimicrobial Use and Resistance (AUR) Module
Table of Contents
Introduction
1. Antimicrobial Use (AU) Option
Introduction
Requirements
Data Analyses
Appendix A. Table of Instructions: Antimicrobial Use
Appendix B. List of Antimicrobials
Appendix C. Example Calculations of Antimicrobial Days
2. Antimicrobial Resistance (AR) Option
Introduction
Requirements
Data Analyses
Appendix A. List of Microorganisms for Antimicrobial Resistance
Appendix B. SNOMED Codes to Identify Eligible Specimen Types
Appendix C. Technical and Isolate Based Report Variables
Appendix D. Denominator Data Variables

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35
37

Introduction
This module contains two options, one focused on antimicrobial usage and the second on
antimicrobial resistance. To participate in either option, facility personnel responsible for
reporting antimicrobial use (AU) or resistance (AR) data to the National Healthcare Safety
Network (NHSN) must coordinate with their laboratory and/or pharmacy information software
providers to configure their system to enable the generation of standard formatted file(s) to be
imported into NHSN. The format provided for data submission follows the Health Level (HL7)
Clinical Document Architecture (CDA).7 Manual data entry is not available for the AUR
Module.
Purpose:
The goal of this National Healthcare Safety Network (NHSN) AUR Module is to provide a
mechanism for facilities to report and analyze antimicrobial use and/or resistance as part of local
or regional efforts to reduce antimicrobial resistant infections through antimicrobial stewardship
efforts or interruption of transmission of resistant pathogens at their facility.6

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1. Antimicrobial Use (AU) Option
Introduction
Rates of resistance to antimicrobial agents continue to increase at hospitals in the United States.1
The two main reasons for this increase are patient-to-patient transmission of resistant organisms
and selection of resistant organisms because of antimicrobial exposure.2 Previous studies have
shown that feedback of reliable reports of rates of antimicrobial use and resistance to clinicians
can improve the appropriateness of antimicrobial usage.3-5
Objectives: The primary objective of the Antimicrobial Use option is to facilitate risk-adjusted
inter- and intra-facility benchmarking of antimicrobial usage. A secondary objective is to
evaluate trends of antimicrobial usage over time at the facility and national levels.
Methodology: The primary antimicrobial usage metric reported to this module is antimicrobial
days per 1000 days present. An antimicrobial day (also known as day of therapy) is defined by
any amount of a specific antimicrobial agent administered in a calendar day to a particular
patient as documented in the electronic medication administration record (eMAR) and/or bar
coding medication record (BCMA) (refer to Numerator Data Section); all antimicrobial days for
a specific agent administered across a population are summed in aggregate.8-11 Days present are
defined as the aggregate number of patients housed to a patient-care location or facility anytime
throughout a day during a calendar month (refer to Denominator Data Section). For each
facility, the numerator (i.e., antimicrobial days) is aggregated by month for each patient-care
location and overall for inpatient areas facility-wide (i.e., facility-wide-inpatient). Similarly, the
denominator (i.e., days present) is calculated for the corresponding patient-care-location-month
or facility-wide-inpatient-month. A secondary antimicrobial usage metric for facility-wideinpatient also reported to this module is antimicrobial days per 1000 admissions. The numerator
and denominators are further defined below and must adhere to the data format prescribed by the
HL7 CDA Implementation Guide developed by the CDC and HL7.7
Settings: NHSN encourages submission of all NHSN-defined inpatient locations, facility-wideinpatient, and select outpatient acute-care settings (i.e., outpatient emergency department,
pediatric emergency department, 24-hour observation area) at each facility (Table 1). The
patient-care areas may include adult, pediatric, or neonatal units as defined by NHSN Codes
(Chapter 15 CDC Locations and Descriptions). A comprehensive submission will enable a
facility to optimize inter- and/or intra-facility comparisons among specific wards, combined
wards, and hospital-wide data. The optional and minimal requirements for participation in the
Antimicrobial Use option are listed in Table 1.
The minimal requirement for participation is submission of data for all four of the following
locations (if applicable to facility): 1) all medical critical care units(s) and surgical critical care
units(s) [if combined units, then report as medical/surgical critical care unit(s)]; 2) all medical
ward(s) and surgical ward(s) [if combined wards, then report as medical/surgical ward(s)]; 3) at

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least one specialty care area; and 4) facility-wide-inpatient (both days present and admissions
must be reported for this location).
Table 1. CDC Locationa: Optional and Minimal Requirements for AU Option
Inpatient Locations
Minimal Submission Requirements (if applicable for facility)
Requirement:
Adult Critical Care Units
For facilities with only adult critical care unit(s): submit all
medical critical care unit(s) and surgical critical care units(s) [if
combined units, then report as medical/surgical critical care
unit(s)].

Pediatric Critical Care Units

For facilities with adult and pediatric critical care unit(s), the
minimum requirement is the submission of data from all adult
and pediatric critical care locations.
Requirement:
For facilities with only pediatric critical care unit(s): submit all
medical critical care unit(s) and surgical critical care units(s) [if
combined units, then report as medical/surgical critical care
unit(s)].

Neonatal Units
Inpatient Specialty Care Areas
Inpatient Adults Wards

For facilities with adult and pediatric critical care unit(s), the
minimum requirement is the submission of data from all adult
and pediatric critical care locations.
Optional (i.e., no minimal submission requirement)
Requirement: At least one Specialty Care Area
Requirement:
For facilities with only adult medical and surgical ward(s), submit
all medical ward(s) and surgical ward(s) [if combined wards, then
report as medical/surgical ward(s)].

Inpatient Pediatric Wards

For facilities with adult and pediatric medical and surgical
ward(s), the minimum requirement is the submission of data from
all adult and pediatric medical and surgical ward locations.
Requirement:
For facilities with only pediatric medical and surgical ward(s),
submit all medical ward(s) and surgical ward(s) [if combined
wards, then report as medical/surgical ward(s)].

Step Down Units
Operating Rooms
Long Term Care

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For facilities with adult and pediatric medical and surgical
ward(s), the minimum requirement is the submission of data from
all adult and pediatric medical and surgical ward locations.
Optional (i.e., no minimal submission requirement)
Optional (i.e., no minimal submission requirement)
Optional (i.e., no minimal submission requirement)

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Inpatient Locations
Facility-Wide
Facility-wide-inpatient
Outpatient Locations
Select Acute Care Settings
Outpatient Emergency
Department
Pediatric Emergency
Department
24-Hour Observation Area

Minimal Submission Requirements (if applicable for facility)
Minimal Submission Requirements (if applicable for facility)
Requirement: Facility-wide-inpatient
Minimal Submission Requirements (if applicable for facility)
Optional (i.e., no minimal submission requirement)

a

CDC Location: A CDC-defined designation given to a patient-care area housing patients who
have similar disease conditions or who are receiving care for similar medical or surgical
specialties. Each facility location that is monitored is “mapped” to one CDC Location. The
specific CDC Location code is determined by the type of patients cared for in that area according
to the 80% Rule. That is, if 80% of patients are of a certain type (e.g., pediatric patients with
orthopedic problems), then that area is designated as that type of location (in this case, an
Inpatient Pediatric Orthopedic Ward). See Locations chapter for more information regarding
location mapping.
Requirements:
An acceptable minimal month of data includes:
a. Data submitted for all four of the following locations (if applicable to facility): 1) all medical
critical care unit(s) and surgical critical care unit(s) [if combined units, then report as
medical/surgical critical care unit(s)]; 2) all medical ward(s) and surgical ward(s) [if combined
wards, then report as medical/surgical ward(s)]; 3) at least one specialty care area; and 4)
facility-wide-inpatient (both days present and admissions must be reported for this location).
b. Each month, the facility must choose to monitor antimicrobial use data on the Patient Safety
Monthly Reporting Plan (CDC 57.106)
c. All data fields outlined in the Table of Instructions (Appendix A) for the AU option are
completed via CDA for each location.
Numerator Data (Antimicrobial Days):
Antimicrobial Days (Days of Therapy): Defined as the aggregate sum of days for which any
amount of a specific antimicrobial agent was administered to individual patients as documented
in the eMAR and/or BCMA.8-11 Appendix B provides a list of antimicrobial agents. Aggregate
antimicrobial days are reported monthly for inpatient locations, facility-wide-inpatient, and select
outpatient acute-care settings (e.g., outpatient emergency department, pediatric emergency
department, 24-hour observation area) for select antimicrobial agents and stratified by route of
administration (e.g., intravenous, intramuscular, digestive and respiratory). Refer to Table 2 and
Table 3 for definitions of drug-specific antimicrobial days and stratification based on route of
administration. For example, a patient to whom 1 gram vancomycin is administered
intravenously twice daily for three days will be attributed three “Vancomycin Days (total)” and

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three “Vancomycin Days (IV)” when stratified by intravenous route of administration. Appendix
C provides additional examples for the calculation of antimicrobial days. Table 4 summarizes
the data elements for numerator calculation. Please note that “zero” should be recorded when no
aggregate usage occurred during a given reporting period for a specific antimicrobial agent at a
facility in which the agent is used, while “not applicable” should be recorded when data are not
available for a specific antimicrobial agent at a facility (e.g., the agent can’t be electronically
captured at that facility). A value (e.g., a specific number, “zero”, or “not applicable”) should be
reported for every antimicrobial agent listed in Appendix B.
Table 2. Classification and Definitions of Route of Administrations for Antimicrobial Days
Classification:
Definitionb
Route of Administrationa
Intravenous
An intravascular route that begins with a vein.
Intramuscular
A route that begins within a muscle.
Digestive Tract
A route that begins anywhere in the digestive tract extending
from the mouth through rectum.
Respiratory Tract
A route that begins within the respiratory tract, including the
oropharynx and nasopharynx.
a
Other routes of administration are excluded in this module (e.g., antibiotic locks,
intraperitoneal, intraventricular, irrigation, topical).
b
Definitions per SNOMED Reference Terminology
Table 3. Example Stratification of Antimicrobial Days by Route of Administration
Month/
YearLocation
MonthYear/
Location

Antimicrobial
Agent
Tobramycin

Drug-specific Antimicrobial Days
Total

a

Tobramycin
Days
(Total)

IV

IM

Digestiveb

Respiratory

Tobramycin
Days
(IV)

Tobramycin
Days
(IM)

Tobramycin
Days
(Digestive)

Tobramycin
Days
(Respiratory)

a

Drug-specific antimicrobial days (total) attributes one antimicrobial day for any route of
administration. For example, a patient to whom tobramycin was administered intravenously and
via a respiratory route on the same day would be attributed “one Tobramycin Day (Total)”; the
stratification by route of administration would be “one Tobramycin Day (IV)” and “one
Tobramycin Day (Respiratory)”.
b
For purposes of example of route stratification only (tobramycin not FDA approved for
administration via the digestive route).

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Table 4. Data Elements for Antimicrobial Days
Antimicrobial
Agents

Data source

Location

Time Unit

Antimicrobial Days
Defined as select antimicrobial agents and stratified by route of administration (i.e.,
intravenous, intramuscular, digestive and respiratory). Refer to Appendix B for a
complete list of antimicrobial agents. The list of select antimicrobial agents will
evolve with time as new agents become commercially available. Topical
antimicrobial agents are not included in this module option.
Antimicrobial days are derived from administered data documented in the eMAR
and/or BCMA only. Usage derived from other data sources (e.g., pharmacy orders,
doses dispensed, doses billed) cannot be submitted.
Antimicrobial days are aggregated for inpatient locations, facility-wide-inpatient, and
select outpatient acute-care settings (i.e., outpatient emergency department, pediatric
emergency department, 24-hour observation area) per NHSN location definitions.
Antimicrobial days for a specific antimicrobial agent and stratification by route of
administration are aggregated monthly per location.

Denominator Data (Days Present and Admissions): The numerator will be analyzed against
the denominator of days present and also admissions for facility-wide-inpatient only. The
denominators are further defined below.
Days present: Defined as time period during which a given patient is at risk for antimicrobial
exposure for a given patient location. The definition of days present differs from conventional
definition of patient days used in other NHSN modules and that recommended by the
SHEA/HIPAC guidance for surveillance of multidrug-resistant organisms.12 Days present is
further defined below in context of calculation for patient care location specific analyses and
facility-wide-inpatient analyses. Please note that a separate calculation for days present is
required for patient-care location compared to facility-wide-inpatient.
For patient-care location-specific analyses, days present is calculated as the number of
patients who were present for any portion of each day of a calendar month for a patientcare location; the aggregate measure is calculated by summing up all of the days present
for that location and month. The day of admission, discharge, and transfer to and from
locations will be included in days present. For example, a patient admitted to the medical
ward on Monday and discharged two days later on Wednesday will be attributed three
days present on that medical ward. Another example, on the day a patient is transferred
from a medical critical-care unit to a medical ward; the patient will be attributed one day
present on the medical critical care unit as well as one day present on the medical ward.
Similarly, a patient’s exposure to the operating room or emergency department will be
included in days present for these types of units. However, one patient can account for
only one day present for a specific location per calendar day (e.g., one patient cannot
contribute more than 1 day present to any one unique location on the same day, but can
contribute a day present to two different locations on the same day). For example, a
patient transferred from the surgical ward to the operating room and back to the surgical
ward in a calendar day contributes one day present to the surgical ward and one day
present to the operating room.
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For facility-wide-inpatient analyses, days present is calculated as the number of patients
who were present for any portion of each day of a calendar month at the facility-wideinpatient location; the aggregate measure is calculated by summing up all of the days
present for facility-wide-inpatient for a given month. Thus, a sum of days present from
location-specific analyses would be higher than days present for the facility, because
transfers between wards can account for multiple location “days present” for a given
patient. Therefore, the individual summing of days present for location-specific analyses
to achieve facility-wide-inpatient is not permissible. The calculation must be a separate
summation for facility-wide-inpatient analyses.
Admissions: Admissions are defined as the aggregate number of patients admitted to the facility
(i.e., facility-wide-inpatient) starting on first day of each calendar month through the last day of
the calendar month. This is the same definition for admissions utilized in the NHSN
MDRO/CDI Module. In the AU option, admissions are reported only for facility-wide-inpatient.
Table 5. Location-specific and Facility-wide-inpatient Metrics
Metric Collected Metric Definition
Comments
Inpatient Care Location-Specific Analyses
Antimicrobial
Drug-specific antimicrobial days per One patient can contribute only
Days/Days
patient-care location per
one day present per calendar
present
month/Days present per patient-care day for each specific location.
location per month
Summed total may be higher
when compared to facilitywide measure (reflecting
transfers between locations).
Facility-wide-inpatient Analyses
Antimicrobial
Drug-specific antimicrobial days for One patient can contribute only
Days/Days
a facility per month/Days present
one day present per calendar
present
per facility-wide-inpatient per month day for a facility. Thus, one
denominator is obtained for an
entire facility. The day present
measure for facility-wideinpatient may be lower when
compared to sum total from
location-specific comparison.
Antimicrobial
Drug-specific antimicrobial days for Only calculated for facilityDays/Admissions a facility per month/Admissions per wide-inpatient for AU Option.
facility-wide-inpatient per month
Data Analyses:
Antimicrobial use data are expressed as incidence density rates of antimicrobial days per days
present stratified by patient-care location and facility-wide-inpatient. Antimicrobials may be
grouped during analysis by route of administration, spectrum of activity, therapeutic indication,
or drug classification.

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A secondary metric, antimicrobial days per admissions, will also be analyzed for facility-wideinpatient.

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References
1. Hidron AI, Edwards JR, Patel J, et al. Antimicrobial-resistant pathogens associated with
healthcare-associated infections: annual summary of data reported to the National
Healthcare Safety Network at the Centers for Disease Control and Prevention, 20062007. Infect Control Hosp Epidemiol 2008;29:996-1011.
2. Schwartz MN. Use of antimicrobial agents and drug resistance. N Eng J Med
1997;337:491-2.
3. Ansari F, Gray K, Nathwani D, et al. Outcomes of an intervention to improve hospital
antibiotic prescribing; interrupted time series with segmented regression analysis. J
Antimicrob Chemother 2003;52:842-8.
4. Solomon DH, Van Houten L, Glynn RJ. Academic detailing to improve use of broadspectrum antibiotics at an academic medical center. Arch Inter Med 2001;161:1897-902.
5. Fraser GL, Stogsdill P, Dickens JD Jr, et al. Antibiotic optimizations: an evaluation of
patient safety and economic outcomes. Arch Inter Med 1997;157-1689-94.
6. Dellit TH, Owens RC, McGowan JE, et al. Infectious Diseases Society of America and
the Society for Healthcare Epidemiology of America Guidelines for Developing an
Institutional Program to Enhance Antimicrobial Stewardship. Clin Infect Dis
2007;44:159-77.
7. National Healthcare Safety Network (NHSN) Patient Safety Component: Clinical
Document Architecture. http://www.cdc.gov/nhsn/CDA/index.html
8. Schwartz DN, Evans RS, Camins B, et al. Deriving measures of intensive care unit
antimicrobial use from computerized pharmacy data: methods, validation, and
overcoming barriers. Infect Control Hosp Epidemiol 2011;32:472-80.
9. Polk RE, Fox C, Mahoney A, Letcavage J, MacDougall C. Measurement of adult
Antibacterial Drug Use in 130 US Hospitals: Comparison of Defined Daily Dose and
Days of Therapy. Clin Infect Dis 2007;44:664-70.
10. Kuster SP, Ledergerber B, Hintermann A, et al. Quantitative antibiotic use in hospitals:
comparison of measurements, literature review, and recommendations for standards of
reporting. Infection 2008; 6:549-59.
11. Berrington A. Antimicrobial prescribing in hospitals: be careful what you measure. J
Antimicrob Chemother 2010:65:163-168.
12. Cohen AL, Calfee D, Fridkin SK, et al. Recommendations for metrics for multidrugresistant organisms in healthcare settings: SHEA/HICPAC position paper. Infect Control
Hosp Epidemiol 2008:29:901-13.

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Appendix A. Table of Instructions: Antimicrobial Use
Data Field
Facility identifier
Month
Year
Location

Numerator:

Instructions for CDA of Antimicrobial Use Data
Required. Must be assigned to facility and included in the importation file prior to
submission to CDC.
Required. Record the 2-digit month during which the data were collected for this
location.
Required. Record the 4-digit year during which the data were collected for this
location.
Required. Record location; must be (if applicable to facility): 1) all medical
critical care unit(s) and surgical critical care unit(s) [if combined units, then report
as medical/surgical critical care unit(s)]; 2) all medical ward(s) and surgical
ward(s) [if combined wards, then report as medical/surgical ward(s)]; 3) at least
one specialty care area; and 4) facility-wide-inpatient
Required.

Antimicrobial days per Antimicrobial days are defined as the aggregate sum of the days of exposure for
month per location
which a specific antimicrobial was administered. These are required to be
extracted from electronic medication administration record (eMAR) and/or bar
coding medication record (BCMA). Antimicrobials days will be collected for
select antimicrobial agents (refer to Appendix B) and stratified by route of
administration.
Denominator:
Required.
Days present

Admissions

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Days present is defined as risk for antimicrobial exposure per time unit of analysis
stratified by location. For patient-care location-specific analyses, days present is
calculated as the number of patients who were present for any portion of each day
of a calendar month for a patient-care location. For facility-wide-inpatient
analyses, days present is calculated as the number of patients who were present for
any portion of each day of a calendar month at the facility-wide-inpatient location
Admissions are defined as the aggregate number of patients admitted to the facility
(i.e., facility-wide-inpatient) starting on first day of each calendar month through
the last day of the calendar month. In the AUR Use Option, admissions are only
reported for facility-wide-inpatient.

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Appendix B. List of Antimicrobials
Please note that mapping of standardized terminology (RXNORM) are provided PHIN
Vocabulary Access and Distribution System (VADS).
Antimicrobial Agent
AMANTADINE

Antimicrobial
Category
Anti-influenza

Antimicrobial
Classa
M2 ion channel inhibitors

AMIKACIN

Antibacterial

Aminoglycosides

AMOXICILLIN

Antibacterial

Penicillins

Aminopenicillin

AMOXICILLIN/
CLAVULANATE
AMPHOTERICIN B

Antibacterial

Penicillins

Β-lactam/ Β-lactamase
inhibitor combination

Antifungal

Polyenes

AMPHOTERICIN B
LIPOSOMAL
AMPICILLIN

Antifungal

Polyenes

Antibacterial

Penicillins

Aminopenicillin

AMPICILLIN/
SULBACTAM
ANIDULAFUNGIN

Antibacterial

Penicillins

Β-lactam/ Β-lactamase
inhibitor combination

Antifungal

Echinocandins

AZITHROMYCIN

Antibacterial

Macrolides

AZTREONAM

Antibacterial

Monobactams

CASPOFUNGIN

Antifungal

Echinocandins

CEFACLOR

Antibacterial

Cephalosporins

Cephalosporin 2rd generation

CEFADROXIL

Antibacterial

Cephalosporins

Cephalosporin 1st generation

CEFAZOLIN

Antibacterial

Cephalosporins

Cephalosporin 1st generation

CEFDINIR

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

CEFDITOREN

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

CEFEPIME

Antibacterial

Cephalosporins

Cephalosporin 4th generation

CEFIXIME

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

CEFOTAXIME

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

CEFOTETAN

Antibacterial

Cephalosporins

Cephamycin

CEFOXITIN

Antibacterial

Cephalosporins

Cephamycin

CEFPODOXIME

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

CEFPROZIL

Antibacterial

Cephalosporins

Cephalosporin 2rd generation

CEFTAROLINE

Antibacterial

Cephalosporins

Cephalosporin 5th generation

CEFTAZIDIME

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

CEFTIBUTEN

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

CEFTIZOXIME

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

CEFTRIAXONE

Antibacterial

Cephalosporins

Cephalosporin 3rd generation

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Antimicrobial Agent
CEFUROXIME

Antimicrobial
Category
Antibacterial

Antimicrobial
Classa
Cephalosporins

Antimicrobial
Subclassa
Cephalosporin 2rd generation

CEPHALEXIN

Antibacterial

Cephalosporins

Cephalosporin 1st generation

CHLORAMPHENICOL

Antibacterial

Phenicols

CIPROFLOXACIN

Antibacterial

Fluoroquinolones

CLARITHROMYCIN

Antibacterial

Macrolides

CLINDAMYCIN

Antibacterial

Lincosamides

COLISTIMETHATE

Antibacterial

Polymyxins

DAPTOMYCIN

Antibacterial

Lipopeptides

DICLOXACILLIN

Antibacterial

Penicillins

DORIPENEM

Antibacterial

Carbapenems

DOXYCYCLINE

Antibacterial

Tetracyclines

ERTAPENEM

Antibacterial

Carbapenems

ERYTHROMYCIN

Antibacterial

Macrolides

ERYTHROMYCIN/
SULFISOXAZOLE
FIDAXOMICIN

Antibacterial
Antibacterial

Folate pathway inhibitors/
Sulfonamides
Macrocyclic

FLUCONAZOLE

Antifungal

Azoles

FOSFOMYCIN

Antibacterial

Fosfomycins

GEMIFLOXACIN

Antibacterial

Fluoroquinolones

GENTAMICIN

Antibacterial

Aminoglycosides

IMIPENEM/
CILASTATIN
ITRACONAZOLE

Antibacterial

Carbapenems

Antifungal

Azoles

LEVOFLOXACIN

Antibacterial

Fluoroquinolones

LINEZOLID

Antibacterial

Oxazolidinones

MEROPENEM

Antibacterial

Carbapenems

METRONIDAZOLE

Antibacterial

Nitroimidazoles

MICAFUNGIN

Antifungal

Echinocandins

MINOCYCLINE

Antibacterial

Tetracyclines

MOXIFLOXACIN

Antibacterial

Fluoroquinolones

NAFCILLIN

Antibacterial

Penicillins

NITROFURANTOIN

Antibacterial

Nitrofurans

OSELTAMIVIR

Anti-influenza

Neuraminidase inhibitors

OXACILLIN

Antibacterial

Penicillins

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Penicillinase-stable
penicillins

Penicillinase-stable
penicillins

Penicillinase-stable

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Antimicrobial Agent

Antimicrobial
Category

Antimicrobial
Classa

Antimicrobial
Subclassa
penicillins

PENICILLIN G

Antibacterial

Penicillins

Penicillin

PENICILLIN V

Antibacterial

Penicillins

Penicillin

PIPERACILLIN

Antibacterial

Penicillins

Ureidopenicillin

PIPERACILLIN/
TAZOBACTAM
POLYMYXIN B

Antibacterial

Penicillins

Β-lactam/ Β-lactamase
inhibitor combination

Antibacterial

Polymyxins

POSACONAZOLE

Antifungal

Azoles

QUINUPRISTIN/
DALFOPRISTIN
RIFAMPIN

Antibacterial

Streptogramins

Antibacterial

Rifampin

RIMANTADINE

Anti-influenza

M2 ion channel inhibitors

SULFAMETHOXAZOLE/
TRIMETHOPRIM
SULFISOXAZOLE

Antibacterial

Folate pathway inhibitors

Antibacterial

Folate pathway inhibitors

TELAVANCIN

Antibacterial

Lipo-glycopeptides

TELITHROMYCIN

Antibacterial

Ketolides

TETRACYCLINE

Antibacterial

Tetracyclines

TICARCILLIN/
CLAVULANATE
TIGECYCLINE

Antibacterial

Penicillins

Antibacterial

Glycylcyclines

TINIDAZOLE

Antibacterial

Nitroimidazoles

TOBRAMYCIN

Antibacterial

Aminoglycosides

VANCOMYCIN

Antibacterial

Glycopeptides

VORICONAZOLE

Antifungal

Azoles

ZANAMIVIR

Anti-influenza

Neuraminidase inhibitors

a

Adapted from CLSI January 2010

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Appendix C. Example Calculations of Antimicrobial Days
Example 1. Example eMAR and Calculation of Antimicrobial Days
This example illustrates the calculation of antimicrobial days from a patient receiving
meropenem 1gram intravenously every 8 hours and amikacin 1000mg intravenously every 24
hours in the medical ward. Table 1 provides an example of administered doses for this patient
documented in eMAR. Table 2 illustrates the calculation of meropenem and amikacin days by
drug-specific (total) and stratified by route of administration based upon the administered doses
of meropenem and amikacin documented in eMAR. Table 3 illustrates the contribution of this
patient’s antimicrobial days to the aggregate monthly report per patient-care location.
Table 1. Example eMAR for Patient housed in Medical Ward
Medical Ward
Monday
Tuesday
December 28
December 29
Meropenem 1gram
intravenously every 8 hours

Given: 2300

Given: 0700
Given: 1500
Given: 2300

Amikacin 1000mg
intravenously every 24 hours

Given: 2300

Given: 2300

Table 2. Example of calculation of antimicrobial days
Calculation
Monday
Tuesday
December 28
December 29
Drug-specific Antimicrobial
Days (total)
Drug-specific Antimicrobial
Days by Stratification of
Route of Administration

Meropenem Days = 1
Amikacin Days = 1
Meropenem Days
(IV) = 1
Amikacin Days
(IV) = 1

Meropenem Days = 1
Amikacin Days = 1
Meropenem Days
(IV) = 1
Amikacin Days
(IV) = 1

Wednesday
December 30
Given: 0700

Wednesday
December 30
Meropenem Days = 1
Amikacin Days = 0
Meropenem Days
(IV) = 1
Amikacin Days
(IV) = 0

Table 3. Example of antimicrobial days per month per patient-care location
Month/
Antimicrobial
Drug-specific Antimicrobial Days
YearAgent
Location
Total
IV
IM
Digestive
Respiratory
December
Medical Ward
December
Medical Ward

January 2014

Meropenem

3

3

0

0

0

Amikacin

2

2

0

0

0

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Example 2. Differences in Calculation for Patient-Care Location and Facility-WideInpatient for a Patient Transferred Between Patient-Care Locations
This example illustrates the calculation of antimicrobial days from a patient receiving
vancomycin 1gram every 8 hours that was transferred from the MICU to a medical ward on
December 1. Table 1 provides an example of doses documented in eMAR administered to this
patient in the MICU and medical ward. Table 2 illustrates the calculation of vancomycin days
by drug-specific (total) and stratified by route of administration based upon the administered
doses of vancomycin documented in eMAR. Table 3 illustrates the contribution of this patient’s
vancomycin days to the aggregate monthly report per patient-care location and facility-wideinpatient.
Table 1. Example eMAR for Patient transferred from MICU to Medical Ward on December
1.
Tuesday
Tuesday
December 1
December 1
Location: MICU
Location: Medical Ward
Vancomycin 1gram intravenously
every 8 hours

Given: 0700

Given: 1500
Given: 2300

Table 2. Example of calculation of antimicrobial days for December 1
Calculation
Tuesday,
Tuesday
December 1
December 1Location:
Location: MICU
Medical Ward
Drug-specific Antimicrobial Days
(total)
Drug-specific Antimicrobial Days
by Stratification of Route of
Administration

Vancomycin Days = 1

Vancomycin Days = 1

Vancomycin Days
(IV) = 1

Vancomycin Days
(IV) = 1

Table 3. Example of antimicrobial days per month per patient-care location and facility-wide
inpatient contributed from December 1
Month/
Antimicrobial
Drug-specific Antimicrobial Days
YearAgent
Location
Total
IV
IM
Digestive
Respiratory
December
MICU
December
Medical Ward
December
Facility-wideinpatient

January 2014

Vancomycin

1

1

0

0

0

Vancomycin

1

1

0

0

0

Vancomycin

1

1

0

0

0

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Example 3. Calculation of Antimicrobial Days for a Patient-Care Location when a Patient
Admission extends over Two Different Months
This example illustrates the calculation of antimicrobial days from a patient receiving ceftriaxone
1gram intravenously every 24 hours for two days in the surgical ward (but spanning different
months). Table 1 provides an example of administered doses for this patient documented in
eMAR. Table 2 illustrates the calculation of ceftriaxone days by drug-specific (total) and
stratification of route of administration based upon the administered doses of ceftriaxone
documented in eMAR. Table 3 illustrates the contribution of this patient’s ceftriaxone days to
the aggregate monthly report per patient-care location.
Table 1. Example eMAR for Patient housed in Surgical Ward
Thursday
Friday
December 31
January 1
Location: Surgical Ward
Location: Surgical Ward
Ceftriaxone gram
intravenously every 24 hours

Given: 0800

Given: 0800

Table 2. Example of calculation of antimicrobial days
Calculation
Thursday
December 31
Location: Surgical Ward
Drug-specific Antimicrobial
Days (total)
Drug-specific Antimicrobial
Days by Stratification of
Route of Administration

Friday
January 1
Location: Surgical Ward

Ceftriaxone Day = 1

Ceftriaxone Day = 1

Ceftriaxone Day
(IV) = 1

Ceftriaxone Day
(IV) = 1

Table 3. Example of antimicrobial days per month per patient-care location
Month/
Antimicrobial
Drug-specific Antimicrobial Days
YearAgent
Location
Total
IV
IM
Digestive
December/
Surgical Ward
January/
Surgical Ward

January 2014

Respiratory

Ceftriaxone

1

1

0

0

0

Ceftriaxone

1

1

0

0

0

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2. Antimicrobial Resistance (AR) Option
Introduction
Common measures of antimicrobial resistance include the proportion of isolates resistant to
specific antimicrobial agents. This proportion resistant (%R) is used to aid in clinical decision
making (hospital antibiograms) as well as for assessing impact of cross transmission prevention
success or antimicrobial stewardship success, although the measure may not be very sensitive to
measuring success of efforts in the short term. An additional value of measuring the proportion
resistant includes a local or regional assessment of progression or improvement of a particular
resistance problem, to guide local or regional cross-transmission prevention efforts. By utilizing
standard methodology of aggregating proportion resistant, local and regional assessments of the
magnitude of a particular resistance phenotype will be more valid.
Objectives:
1. Facilitate evaluation of antimicrobial resistance data using a standardized approach to:
a. Provide local practitioners with an improved awareness of a variety of
antimicrobial-resistance problems to both aid in clinical decision making and
prioritize transmission prevention efforts.
b. Provide facility-specific measures in context of a regional and national
perspective (i.e., benchmarking) which can inform decisions to accelerate
transmission prevention efforts and reverse propagation of emerging or
established problematic resistant pathogens.
2. Regional and national assessment of resistance of antimicrobial resistant organisms of
public health importance including ecologic assessments and infection burden.
Methodology:
Antimicrobial resistance data are reported as a proportion and rate in this module.1 The
proportion resistant is defined as the number of resistant isolates divided by the number of
isolates tested for the specific antimicrobial agent being evaluated. In comparison, the
antimicrobial resistance rate is defined as the number of resistant isolates per 1000 patient days.
For each facility, the numerator (i.e., number of resistant isolates) is derived from isolate-level
reports submitted. The denominators of patient days and admissions can be obtained from the
ADT system. The numerator and denominator are further defined below and must adhere to the
data format prescribed by the HL7 CDA Implementation Guide developed by the CDC and
HL7.2
Settings:
NHSN encourages reporting specimens from all NHSN-defined inpatient locations and select
outpatient acute-care settings (i.e., outpatient emergency department, pediatric emergency
department, 24-hour observation area) at each facility. The denominators of patient days and
admissions are only required at the facility-wide inpatient level (FacWideIN). Eligible facilities
include any facility using the Patient Safety Component of NHSN.

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Requirements:
Each month:
1. The facility must choose to monitor antimicrobial resistance data on the Patient Safety
Monthly Reporting Plan (CDC 57.106).
2. Two record types must be reported for each month of surveillance.
• One for each isolate-based report
• One for the denominator data report (facility-wide inpatient-FacWideIN)
Specimen sources
1. Eligible non-invasive specimen sources include lower respiratory (e.g., sputum,
endotracheal, bronchoalveolar lavage) and urine specimens.
2. Eligible invasive specimen sources include cerebrospinal fluid (CSF) and blood
specimens.
Isolate-based report
Report all required data each month for each eligible isolate-based report (See Appendix A).
Eligible isolate-based reports must have had susceptibility testing performed. This should be
consistent with CLSI M39 Guidance on reporting cumulative susceptibility test results. Two
distinct events should be reported.
1. Each eligible organism isolated from invasive source per patient, per 14 day period even
across calendar months (i.e., report all unique invasive sources).
a. There should be 14 days with no positive culture result from the laboratory for the
patient and organism before another invasive source Antimicrobial Resistance
(AR) Event is entered into NHSN for the patient and organism. NOTE: The date
of specimen collection is considered Day 1.
b. After >14 days have passed with no positive culture results for that specific
organism, another positive culture from an invasive source with that organism can
be reported as an AR Event.
2. First eligible organism isolated from any eligible non-invasive culture source, per
patient, per month.
A. Eligible organisms include:
• Acinetobacter
• Candida albicans
• Candida glabrata
• Citrobacter freundii
• Enterobacter
• Enterococcus faecalis
• Enterococcus faecium

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•
•
•
•
•
•
•
•
•
•
•
•

Enterococcus spp. (when not specified to the species level)
Escherichia coli
Group B Streptococcus
Klebsiella oxytoca
Klebsiella pneumoniae
Morganella morganii
Proteus mirabilis
Pseudomonas aeruginosa
Serratia marcescens
Staphylococcus aureus
Stenotrophomonas maltophilia
Streptococcus pneumoniae

B. Specimen Sources (Appendix B)
• Eligible non-invasive sources (one per patient, per organism, per month) include:
o Lower respiratory (e.g., sputum, endotracheal, bronchoalveolar lavage)
o Urine
•

Unique invasive source (one per patient, per organism, per >14 days) (i.e., should be 14
days with no positive culture result from the laboratory for the patient and organism
before another invasive source AR Event is entered into NHSN for the patient and
organism):
o Cerebrospinal fluid (CSF)
o Blood
o Important:
 Report blood or CSF cultures growing same eligible organism with no
intervening positive blood or CSF culture (with same eligible organism)
within 14 days.
 In a patient who already has a blood or CSF culture isolate-based report
for a specific organism, only report an additional blood or CSF culture if
there is no prior positive blood or CSF culture for the same genus/species
within 14 days, even across calendar months.
 There should be a full 14 days with no positive blood or CSF culture result
with the same genus/species from the same patient before another unique
invasive source is reported (e.g., there should be >14 days since previous
isolation).


January 2014

EXAMPLE: On January 1, a patient has a positive MRSA blood culture
which is entered into NHSN. On January 4, the same patient has another
MRSA positive blood culture which is not entered into NHSN because it
has not been 14 days since the original positive MRSA blood culture. On
January 16, the same patient has another positive MRSA blood culture.
While it has been more than 14 days since the initial positive MRSA blood

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culture from the same patient was entered into NHSN (January 1), it has
not been >14 days since the patient’s most recent positive MRSA blood
culture (January 4). Therefore, the positive blood culture for January 16 is
not entered into NHSN. On January 31, the patient has another positive
MRSA blood culture. Since it has been >14 days since the patient’s most
recent positive culture (January 16), this event is entered into NHSN.
All isolate test results are evaluated using either the algorithm in Figure 1 (Non-invasive
specimens) or Figure 2 (Invasive specimens) to determine reportable AR events for each
calendar month. For eligible non-invasive specimens, all first non-invasive isolates
(chronologically) per patient, per month, per organism are reported as an AR event (Figure 1).
For eligible invasive specimens, there should be 14 days with no positive culture result from the
laboratory for the patient and organism before another invasive source AR Event is entered into
NHSN for the patient and organism (Figure 2). As a general rule, at a maximum, there should be
no more than 3 invasive isolates reported, which would be very rare. Report each AR Event
individually.
Use SNOMED codes to identify eligible specimen types to be included in identification of
isolate-based report. (Appendix B)
C. Required Data
Required data includes mostly data available from the laboratory information system and
some from administrative data systems. The set of variables for each isolate consists of a
variable to identify the NHSN facility, isolate/patient related data, and antimicrobial
susceptibility data as outlined below. For additional information on each variable please see
Appendix C.
•

Facility identifier
o NHSN Facility ID (facility identifier, unique to NHSN)

•

Isolate / Patient related data
o Patient identifier
o Date of birth
o Gender
o Date admitted to facility
o Specimen collection date
o Specimen source (SNOMED)
o Location code – (mapped to CDC location codes)
o Isolate identifier (unique isolate ID)
o Organism (Appendix A)

•

Antimicrobial susceptibility data
o Antimicrobial (Appendix A)
o PBP2a-agglutination (only if Staphylococcus aureus)

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o
o
o
o
o
o
o
o
o
o
o

PCR mec-gene (only if Staphylococcus aureus)
E-test sign
E-test value
Interpretation of E-test
MIC sign
MIC value
Interpretation of MIC test
Zone sign
Zone value
Interpretation of zone test (disk diffusion)
Final interpretation result

Reporting Guidelines
• Interpretation of test results (E-test, MIC test, Zone test) includes the following results: S
= Susceptible, S-DD = Susceptible-Dose Dependent, I = Intermediate, R = Resistant, NS
= Non-Susceptible, N = Not Tested.
o Specific to Gentamicin and Streptomycin results for Enterococcus testing: S =
Susceptible/Synergistic and R = Resistant/Not Synergistic.
• On a single isolate if no final interpretation, first double check with the lab to ensure
testing is complete. Clarify with the lab why a final interpretation was not provided.
Then prioritize test results for “E-test interpretation > MIC interpretation > Zone
Interpretation.”
• In circumstances where different breakpoints are required, rely on the specimen source to
determine which susceptibility results to report. If the specimen source is CSF report the
meningitis breakpoint susceptibility. If the specimen source is blood, urine, or lower
respiratory report the non-meningitis breakpoint susceptibility.
D. Remove Same Day Duplicates
The goal of this option to capture the first isolate per patient per month from a non-invasive
specimen source and in addition, every unique invasive isolate per patient per 14 day period
(maximum of three per month per patient). However, frequently multiple isolates of the same
species are processed on the same day, often with conflicting results. Only one isolate should
be chosen, retaining the unique nature of the test results. Rules must be in place to ensure
duplicate isolate reports are removed. Duplicates are defined as same species or same genus,
when identification to species level is not provided, from same patient on same day. Isolates
must be of the same source type (i.e., invasive or non-invasive) to be considered duplicates.
Identify observations reflecting multiple isolates within the same day and select the isolate to
report to NHSN based on these rules:
• For non-invasive source isolate selection, lower respiratory isolates should be
selected over urine isolates.
• For invasive source isolate selection, CSF isolates should be selected over blood
isolates.
• Eliminate isolates on same day without susceptibility test results.

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•
•

•
•
•

If the same test is performed the same isolate but they produce conflicting results,
report the most resistant result (i.e., R > I > S).
If two different tests on the same date are performed on the same isolate and produce
conflicting susceptibility interpretations, the individual test results should be reported
for the separate tests. However, the final interpretation should be populated based on
the final laboratory interpretation of the results.
Do not merge test results across multiple isolates (i.e., don’t summarize results across
different isolates tested on same day).
If testing results are indistinguishable or the same test is conducted with the same
results, choose isolate test with more complete fields for other variables.
If two isolates from the same day have conflicting susceptibilities to the panel of
antimicrobials tested, considering the protocol states not to merge the susceptibility
results of isolates if they are different, pick the first in the sequence of the encounter
recorded in the laboratory information system (LIS).

Denominator data report
For each month, report facility-wide denominator data: (See Appendix D)
1. Patient Days: Number of patients present in the facility at the same time period on each
day of the month, summed across all days in the month.
2. Admissions: Number of patients admitted to the facility each month.
Further information on counting patient days and admissions can be found in Appendix 2
of the NHSN MDRO & CDI Module Protocol:
http://www.cdc.gov/nhsn/pscManual/12pscMDRO_CDADcurrent.pdf.
Minimizing Bias
The source of test results should be from the hospital laboratory information system (LIS).
Efforts should be made to reduce selection bias sometimes inherent in systems that have
suppression rules in place which prevent test results from being available in the LIS. For
example, efforts should be made to obtain resistant results that are withheld from clinicians.
Data Analyses:
Antimicrobial resistance data will be expressed using several metrics, likely at quarterly, semiannual, or annual time frame depending on how rare the isolates occurred. (See Table 1)

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Figure 1. Test Result Algorithm for Non-Invasive Specimen Reporting
Eligible organism isolated from non-invasive
source (lower respiratory or urine) per patient

1st in calendar
month per
patient, per
organism

Yes
Should
be
reported

January 2014

No

Additional AR
isolate

AR Event

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Should
not be
reported

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Figure 2. Test Result Algorithm for Invasive Specimen Reporting
Eligible organism isolated from invasive
source (blood or CSF) per patient

Prior (+) isolate
with same organism
from invasive
source in ≤ 2 weeks,
per patient
(including across
calendar months)

Yes

No
Should
be
reported

January 2014

AR Event

Additional
AR isolate

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Should
not be
reported

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Table 1. Current Resistance Metrics
Metric
Definition
Facility-wide-inpatient: standard output for facility and group user.
% non-susceptible (# Resistant + # Intermediate/ # tested)
Drug-specific antimicrobial resistance for a facility /Number of isolates
tested per facility for specific organism-antimicrobial pairing
BSI % non(# Resistant BSI + # Intermediate BSI/# tested)
susceptible
Drug-specific antimicrobial resistance among positive blood cultures
for a facility/Number of isolates from blood cultures tested per facility
for specific organism-antimicrobial pairing
Healthcare facility- Drug-specific antimicrobial resistance (i.e., # non-susceptible) among
onset antimicrobial isolates collected >3 days after admission, for a facility/1000 patientresistance rate
days

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References
1. Schwaber MJ, De-Medina T, and Carmeli Y. Epidemiological interpretation on
antibiotic resistance studies – what are we missing? Nat Rev Microbiol 2004;2:97983.
2. National Healthcare Safety Network (NHSN) Patient Safety Component: Clinical
Document Architecture. http://www.cdc.gov/nhsn/CDA/index.html
3. CLSI. Analysis and Presentation of Cumulative Antimicrobial Susceptibility Test
Data; Approved Guideline – Third Edition. CLSI document M39-A3. Wayne, PA:
Clinical and Laboratory Standards; 2009.

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Appendix A. List of Organisms for Antimicrobial Resistance3
Please note that mapping of standardized terminology (SNOMED) are provided upon
request to the NHSN CDA Team at [email protected]. Testing methods should follow
most recent CLSI guidance as appropriate.
Organism
Acinetobacter

Candida albicans
Candida glabrata

January 2014

Specimen Type
Blood, Urine, Lower
Respiratory, CSF

Antimicrobial Agents
Amikacin
Ampicillin-sulbactam
Cefepime
Cefotaxime
Ceftazidime
Ceftriaxone
Ciprofloxacin
Doxcycline
Gentamicin
Imipenem with Cilastatin
Levofloxacin
Meropenem
Minocycline
Piperacillin
Piperacillin-tazobactam
Tetracycline
Ticarcillin-clavulanate
Tobramycin
Trimethoprim-sulfamethoxazole
Additional Agents for Urine None
Blood, Urine, CSF
Anidulafungin
Note: Lower respiratory will Caspofungin
not be collected for Candida Fluconazole
spp.
Flucytosine
Itraconazole
Micafungin
Posaconazole
Voriconazole
Additional Agents for Urine None

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Organism
Citrobacter freundii
Enterobacter
Escherichia coli
Klebsiella oxytoca
Klebsiella pneumoniae
Morganella morganii
Proteus mirabilis
Serratia marcescens

Specimen Type
Blood, Urine, Lower
Respiratory, CSF

Additional Agents for Urine

January 2014

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Antimicrobial Agents
Amikacin
Amoxicillin-clavulanic acid
Ampicillin
Ampicillin-sulbactam
Aztreonam
Cefazolin
Cefepime
Cefotaxime
Cefoxitin
Ceftazidime
Ceftriaxone
Cefuroxime
Chloramphenicol
Ciprofloxacin
Doripenem
Ertapenem
Gentamicin
Imipenem with Cilastatin
Levofloxacin
Meropenem
Piperacillin
Piperacillin-tazobactam
Tetracycline
Ticarcillin-clavulanic acid
Trimethoprim-sulfamethoxazole
Tobramycin
Cephalothin
Lomefloxacin
Nitrofurantoin
Norfloxacin
Ofloxacin
Sulfisoxazole
Trimethoprim

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Organism
Enterococcus faecalis
Enterococcus faecium
Enterococcus spp. (when
not otherwise specified)
(excluding E. faecalis, E.
faecium, and other
identified species)

Specimen Type
Blood, Urine, Lower
Respiratory, CSF

Additional Agents for Urine
Note: Exclude Gentamicin
and Streptomycin

Pseudomonas aeruginosa

Blood, Urine, Lower
Respiratory, CSF

Additional Agents for Urine

January 2014

11-29

Antimicrobial Agents
Ampicillin
Daptomycin
Gentamicin
Linezolid
Penicillina
Quinupristin/dalfopristin
Rifampin
Streptomycin
Vancomycin
Note: For Gentamicin and
Streptomycin only:
Synergistic = Susceptible
Non-synergistic = Resistant
Ciprofloxacin
Levofloxacin
Nitrofurantoin
Norfloxacin
Tetracycline
Amikacin
Aztreonam
Cefepime
Ceftazidime
Ciprofloxacin
Gentamicin
Imipenem with Cilastatin
Levofloxacin
Meropenem
Piperacillin
Piperacillin-tazobactam
Ticarcillin
Tobramycin
Lomefloxacin
Norfloxacin
Ofloxacin

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Organism
Staphylococcus aureus

Specimen Type
Blood, Urine, Lower
Respiratory, CSF

Additional Agents for Urine

Stenotrophomonas
maltophilia

Blood, Urine, Lower
Respiratory, CSF

Additional Agents for Urine

January 2014

11-30

Antimicrobial Agents
Azithromycin
Cefoxitin
Chloramphenicol
Ciprofloxacin
Clarithromycin
Clindamycin
Daptomycin
Doxycycline
Erythromycin
Gentamicin
Levofloxacin
Linezolid
Minocycline
Moxifloxacin
Ofloxacin
Oxacillin or Nafcillinb
Penicillina
Quinupristin-dalfoprisin
Rifampin
Telithromycin
Tetracycline
Trimethoprim-sulfamethoxazole
Vancomycin
Lomefloxacin
Nitrofurantoin
Norfloxacin
Sulfisoxazole
Trimethoprim
Ceftazidime
Chloramphenicol
Levofloxacin
Minocycline
Ticarcillin-clavulanate
Trimethoprim-sulfamethoxazole
None

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Organism
Specimen Type
Streptococcus pneumoniae Blood, Urine, Lower
Respiratory, CSF

Group B Streptococcus

Additional Agents for Urine
Blood, Urine, Lower
Respiratory, CSF

Additional Agents for Urine

January 2014

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Antimicrobial Agents
Amoxicillin
Amoxicillin-clavulanic acid
Azithromycin
Cefepime
Cefotaxime (meningitis or nonmeningitis breakpoint)c
Ceftriaxone (meningitis or nonmeningitis breakpoint)c
Cefuroxime
Chloramphenicol
Clindamycin
Ertapenem
Erythromycin
Gemifloxacin
Imipenem with Cilastatin
Levofloxacin
Linezolid
Meropenem
Moxifloxacin
Ofloxacin
Penicillina (meningitis or nonmeningitis breakpoint)c
Penicillin Va (oral breakpoint)
Rifampin
Telithromycin
Tetracycline
Trimethoprim-sulfamethoxazole
Vancomycin
None
Ampicillin
Cefazolin
Cefotaxime
Cefoxitin
Ciprofloxacin
Clindamycin
Daptomycin
Erythromycin
Levofloxacin
Linezolid
Penicillina
Tetracycline
Vancomycin
None

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a

If the LIS does not differentiate between Penicillin G and Penicillin V, list susceptibility
results under Penicillin G and indicate that Penicillin V was not tested (N).
b
For Staphylococcus aureus susceptibility testing, if the LIS tests Nafcillin instead of
Oxacillin, report Nafcillin susceptibility results as Oxacillin.
c
If the LIS produces meningitis and non-meningitis breakpoint results, rely on the
specimen source to determine which susceptibility results to report. If the specimen source
is CSF report the meningitis breakpoint susceptibility. If the specimen source is blood,
urine, or lower respiratory report the non-meningitis breakpoint susceptibility.

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Appendix B. SNOMED Codes to Identify Eligible Specimen Types
Please note that mapping of standardized terminology for specimen type are provided upon
request to the NHSN CDA Team at [email protected].

Specimen
Type
Blood
Urine
Cerebral
Spinal Fluid
Lower
Respiratory
Specimens

January 2014

Description
Blood specimen (specimen)
Urinary specimen (specimen)
Cerebrospinal fluid sample (specimen)
coughed sputum specimen (specimen)
specimen from trachea (specimen)
specimen from lung obtained by bronchial washing procedure
(specimen)
specimen from lung obtained by biopsy (specimen)
specimen from lung obtained by fiberoptic bronchoscopic
biopsy (specimen)
upper respiratory fluid specimen obtained by tracheal aspiration
(specimen)
tissue specimen from bronchus (specimen)
tissue specimen from trachea (specimen)
bronchial fluid sample (specimen)
sputum specimen obtained by aspiration (specimen)
sputum specimen obtained by aspiration from trachea
(specimen)
sputum specimen obtained by sputum induction (specimen)
sputum specimen obtained from sputum suction trap (specimen)
lower respiratory tissue sample (specimen)
lower respiratory fluid sample (specimen)
transbronchial lung biopsy sample (specimen)
bronchial biopsy sample (specimen)
bronchial brushings sample (specimen)
tissue specimen from lung (specimen)
specimen obtained by bronchial aspiration (specimen)
specimen obtained by bronchioloalveolar lavage procedure
(specimen)
specimen from trachea obtained by aspiration (specimen)
specimen obtained by bronchial trap (specimen)
bronchial fluid specimen obtained from bronchial trap
(specimen)
sputum specimen (specimen)
specimen from bronchus (specimen)

11-33

SNOMED
CT Code
119297000
122575003
258450006
119335007
119390000
122609004
122610009
122611008
122877000
128158009
128173005
258446004
258608003
258609006
258610001
258611002
309170008
309171007
309173005
309174004
309176002
399492000
441903006
441917002
445447003
446838005
447345009
119334006
119391001

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Specimen
Type

Description
specimen from lung (specimen)
lower respiratory sample (specimen)
bronchoalveolar lavage fluid sample (specimen)
tracheal biopsy sample (specimen)

January 2014

11-34

SNOMED
CT Code
127458004
258606004
258607008
309169007

Antimicrobial Use and Resistance Module
AUR

Appendix C. Isolate Based Report Variables
NAME

DESCRIPTION OF FIELD

Facility ID

NHSN-assigned facility ID number

Patient ID

Alphanumeric patient ID assigned by the
hospital and may consist of any combination
of numbers and/or letters. This should be an
ID that remains the same for the patient across
all visits and admissions.
The date of the patient’s birth including
month, day, and year.
M (Male), F (Female), O (Other) to indicate
the gender of the patient.
Date patient was admitted to an inpatient
facility including month, day, and year. If the
laboratory specimen is reported from an
outpatient location enter a null value.
Date the specimen was collected including
month, day, and year.
Specimen source from which the isolate was
recovered (e.g. urine, lower respiratory,
blood, CSF).
Patient care area where patient was when the
laboratory specimen was collected. Use
patient location obtained from administrative
data system (ADT).
Isolate identifier unique for each isolate
within laboratory and year.
Organism identified from specimen collected
(Appendix A).

Date of Birth
Gender
Date admitted to
facility

Specimen
collection date
Specimen
source
Location

Isolate identifier
Organism

Antimicrobial

PBP2aagglutination
PCR mec-gene

E-test sign
E-test value
Interpretation
of E-test

January 2014

CODE
VALUE LIST

LEVEL OF
REQUIREMENT

NHSN

Required
Required

Required
Required
Required

Required
SNOMED

Required

CDC Location
Codes

Required

Required
SNOMED

Antimicrobial(s) tested for susceptibility
RxNorm
(Appendix A will define agents by organism
and specimen source)
Result for PBP2a-agglutination (only if SA)
Pos/Neg/Unk
Result for PCR mec-gene (only if SA)
Pos/Neg/Unk
E-test sign (> < =).
E-test (Value in micrograms/liter). Use '.' as
decimal delimiter, e.g. 0.25
Interpretation result of the E-test susceptibility
test performed

11-35

Required

Required

Conditional (for
Staph aureus)
Conditional (for
Staph aureus)
Conditional
Conditional
Conditional

Antimicrobial Use and Resistance Module
AUR

NAME
MIC sign
MIC value
Interpretation of
MIC test
Zone sign
Zone value
Interpretation of
Zone test
Final
Interpretation
result

January 2014

DESCRIPTION OF FIELD
MIC sign (> < =).
MIC (Value in micrograms/liter). Use '.' as
decimal delimiter, e.g. 0.25
Interpretation result of the MIC susceptibility
test performed
Zone sign (> < =).
Zone value in millimeters
Interpretation result of the zone susceptibility
test performed
Final interpretation result of all different
susceptibility tests performed

11-36

CODE
VALUE LIST

LEVEL OF
REQUIREMENT
Conditional
Conditional
Conditional
Conditional
Conditional
Conditional
Required

Antimicrobial Use and Resistance Module
AUR

Appendix D. Denominator Data Variables
DESCRIPTION OF FIELD

CODE
VALUE LIST

LEVEL OF
REQUIREMENT

NHSN

Required

Facility Wide Denominator
Facility ID

NHSN –assigned facility ID number

Location

FacWideIN

Required

Month

2-Digit month

Required

Year

4-Digit year

Required

Patient
Days

For facility wide inpatient locations enter the total
number of patient days collected at the same time
each day combined for the month. All of the
facility’s inpatient locations with an overnight stay
should be included where denominators can be
accurately collected.
For facility wide inpatients, enter the total number
of admissions for all facility inpatient locations
combined for the month. All the facility’s inpatient
locations with an overnight stay should be included
where denominators can be accurately collected.

Required

Admission
Count

January 2014

11-37

Required