12

April 2013 CDC/NHSN Protocol Corrections,
Clarification, and Additions
(NOTE: These protocol edits have not yet been added to the current posted
NHSN protocols)
•

Errata [PDF - 291 KB] April 2013

MDRO and CDI Module

Multidrug-Resistant Organism & Clostridium difficile Infection (MDRO/CDI) Module

Table of Contents

Background
Table 1: Core and Supplemental Reporting Choices for MDRO and CDI Module
Section I: Core Reporting
Option 1: Laboratory-Identified (LabID) Event Reporting
1A: MDRO LabID Event Reporting
1B: Clostridium difficile (C. difficile) LabID Event Reporting
Option 2: Infection Surveillance Reporting
2A: MDRO Infection Surveillance Reporting
2B: Clostridium difficile (C. difficile) Infection Surveillance Reporting
Section II: Supplemental Reporting
1. Prevention Process Measures Surveillance
a. Monitoring Adherence to Hand Hygiene
b. Monitoring Adherence to Gown and Gloves Use as Part of Contact
Precautions
c. Monitoring Adherence to Active Surveillance Testing
2. Active Surveillance Testing Outcome Measures
Table 2: Rates and Measures Derived from Various MDRO and CDI Protocol Surveillance
Methods
Appendix 1: Guidance for Handling MDRO and CDI Module Infection Surveillance and LabID
Event Reporting When Also Following Other NHSN Modules
Appendix 2: Determining Patients Days for Summary Data Collection: Observation vs. Inpatients

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Background: Methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus
spp. (VRE), and certain gram-negative bacilli have increased in prevalence in U.S. hospitals over the last
three decades, and have important implications for patient safety. A primary reason for concern about these
multidrug-resistant organisms (MDROs) is that options for treating patients with these infections are often
extremely limited, and MDRO infections are associated with increased lengths of stay, costs, and mortality.
Many of these traits have also been observed for Clostridium difficile infection (CDI). The Healthcare
Infection Control Practices Advisory Committee (HICPAC) has approved guidelines for the control of
MDROs.1 These are available at (http://www.cdc.gov/ncidod/dhqp/pdf/ar/mdroGuideline2006.pdf). The
MDRO and CDI module of the NHSN can provide a tool to assist facilities in meeting some of the criteria
outlined in the guidelines. In addition, many of the metrics used in this module are consistent with
“Recommendations for Metrics for Multidrug-Resistant Organisms in Healthcare Settings: SHEA/HICPAC
Position Paper.”2
Clostridium difficile (C. difficile) is responsible for a spectrum of C. difficile infections (CDI), including
uncomplicated diarrhea, pseudomembranous colitis, and toxic megacolon which can, in some instances, lead
to sepsis and even death. Although CDI represents a subset of gastroenteritis and gastrointestinal tract
infections in the current CDC definitions for HAIs, specific standard definitions for CDI 3 should be
incorporated to obtain a more complete understanding of how C. difficile is being transmitted in a healthcare
facility.
As outlined in the HICPAC guideline1, these MDRO and C. difficile pathogens may require specialized
monitoring to evaluate if intensified infection control efforts are required to reduce the occurrence of these
organisms and related infections. The goal of this module is to provide a mechanism for facilities to report
and analyze these data that will inform infection prevention professionals of the impact of targeted
prevention efforts.
This module contains two reporting options for MDRO and C. difficile, one focused on Laboratoryidentified (LabID) Events reporting and the second on Infection Surveillance reporting. Reporting options
are summarized in Table 1. Participants may choose either 1 or both of the 2 core reporting options and then
may also choose to participate in any of the supplemental monitoring methods described in Table 1.

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Table 1. Core and Supplemental Reporting Choices for MDRO and CDI Module

Reporting Choices

Core
Proxy Infection Measures
LabID Event
Choose ≥1 organism
AND/OR
Infection Surveillance
Choose ≥1 organism
Supplemental
Prevention Process
Measures
Options:
• Hand Hygiene
Adherence
• Gown and Gloves Use
Adherence
• Active Surveillance
Testing (AST)
Adherence

MDRO
VRE

MRSA or
MRSA/MSSA

CDI
C. difficile

Method
A, B, C, D

Method
A, B, C, D

Klebsiella spp.
(CephR or CRE),
E. coli (CRE),
Acinetobacter spp. (MDR)
Method
A, B, C, D

A, B

A, B

A, B

Method

Method

Method

Method

B

B

B

B

B

B

B

B

B

B

N/A

N/A

B

N/A

N/A

AST Outcome Measures
B
• Incident and Prevalent
Cases using AST
N/A – not available or contraindicated.
±

Method
A, B, C

±

±

A, B

No surveillance for CDI will be performed in Neonatal Intensive Care Units (NICU), Specialty Care
Nurseries (SCN), babies in LDRP (Labor, Delivery, Recovery, and Post-partum), well-baby nurseries, or
well-baby clinics. And, if conducting facility-wide monitoring (Method C) the denominator counts
(admissions, patient-days, encounters) for these locations must be removed.

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Reporting Method (must choose to monitor by LabID Event or Infection Surveillance reporting before
supplemental methods can also be used for monitoring):
A:

Facility-wide by location. Report for each location separately and cover all locations in a facility.
This reporting method requires the most effort, but provides the most detail for local and national
statistical data.

B:

Selected locations within the facility (1 or more). Report separately from one or more specific
locations within a facility. This includes reporting individual Events and denominator data for each
of the selected locations. This reporting method is ideal for use during targeted prevention programs.

C:

Overall facility-wide. Report only one denominator for the entire facility and individual LabID
Events from each inpatient location. Options include: overall Facility-wide Inpatient (FacWideIN) to
cover all inpatient locations or overall Facility-wide Outpatient (FacWideOUT) to cover all
outpatient locations. Facilities may choose to monitor both FacWideIN and FacWideOUT.

D:

Overall facility-wide: Blood Specimens Only. This method is available for MDRO LabID Events
only and targets the most invasive events. Options include: overall Facility-wide Inpatient
(FacWideIN) to cover all inpatient locations or overall Facility-wide Outpatient (FacWideOUT) to
cover all outpatient locations. Facilities may choose to monitor both FacWideIN and FacWideOUT.

I. Core Reporting
Option 1: Laboratory-Identified (LabID) Event Reporting
Introduction: LabID Event reporting option allows laboratory testing data to be used without clinical
evaluation of the patient, allowing for a much less labor-intensive method to track MDROs and C. difficile.
These provide proxy infection measures of MDRO and/or C. difficile healthcare acquisition, exposure
burden, and infection burden based almost exclusively on laboratory data and limited admission date data,
including patient care location. LabID Event reporting is ONLY for collecting and tracking positive
laboratory results (e.g., cultures) that are collected for “clinical” purposes (i.e., for diagnosis and treatment).
This means that the results of laboratory specimens collected for active surveillance testing (AST) purposes
only should not be reported as LabID Events.
LabID Events can be monitored at the overall facility-wide level for inpatient areas (FacWideIN) and/or at
the overall facility-wide level for outpatient areas (FacWideOUT). At the overall FacWide levels, the
MDROs can be monitored for all specimen types or for blood specimens only. LabID Events can also be
monitored for specific locations with unique denominator data required from each of the specific locations
(i.e., facility-wide locations monitored separately [Method A] allowing for both facility-wide and locationspecific data, or by selected locations only [Method B]).
Laboratory and admission data elements can be used to calculate a variety of distinct proxy measures
including (see Table 2): admission prevalence rate and overall patient prevalence rate (measures of exposure
burden), MDRO bloodstream infection incidence rate (measure of infection burden and healthcare

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acquisition), overall MDRO infection/colonization incidence rate (measure of healthcare acquisition), and
CDI incidence rate (measure of infection burden and healthcare acquisition).
Use NHSN forms to collect all required data, using the definitions of each data field as indicated in the
Tables of Instructions. When denominator data are available from electronic databases, these sources may
be used as long as the counts are not substantially different (+ or – 5%) from manually collected counts.
A. MDRO LabID Event Reporting
Methodology: Facilities may choose to monitor one or more of the following MDROs: MRSA, MRSA and
MSSA, VRE, CephR- Klebsiella spp., CRE-Klebsiella spp., CRE-E. coli, and multidrug-resistant
Acinetobacter spp (see definitions below). For S. aureus, both the resistant (MRSA) and the susceptible
(MSSA) phenotypes can be tracked to provide concurrent measures of the susceptible pathogens as a
comparison to those of the resistant pathogens in a setting of active MRSA prevention efforts.
NOTE: No Active Surveillance Culture/Testing (ASC/AST) results are to be included in this reporting of
individual results (See Key Terms chapter). Do NOT enter surveillance nasal swabs or other surveillance
cultures as reports of LabID Events. AST tracking should be recorded under Process & Outcome Measures.
MDRO Definitions: MDROs included in this module are defined below.
MRSA: Includes S. aureus cultured from any specimen that tests oxacillin-resistant, cefoxitin-resistant, or
methicillin-resistant by standard susceptibility testing methods, or by a laboratory test that is FDA-approved
for MRSA detection from isolated colonies; these methods may also include a positive result by any FDAapproved test for MRSA detection from specific sources.
MSSA: S. aureus cultured from any specimen testing intermediate or susceptible to oxacillin, cefoxitin, or
methicillin by standard susceptibility testing methods, or by a negative result from a test that is FDAapproved for MRSA detection from isolated colonies; these methods may also include a positive result from
any FDA-approved test for MSSA detection from specific specimen sources.
VRE: Any Enterococcus spp. (regardless of whether identified to the species level), that is resistant to
vancomycin, by standard susceptibility testing methods or by results from any FDA-approved test for VRE
detection from specific specimen sources.
CephR-Klebsiella: Any Klebsiella spp. testing non-susceptible (i.e., resistant or intermediate) to
ceftazidime, cefotaxime, ceftriaxone, or cefepime.
CRE-Ecoli: Any E. coli testing non-susceptible (i.e., resistant or intermediate) to imipenem, meropenem, or
doripenem, by standard susceptibility testing methods or by a positive result for any method FDA-approved
for carbapenemase detection from specific specimen sources.
CRE-Klebsiella: Any Klebsiella spp. testing non-susceptible (i.e., resistant or intermediate) to imipenem,
meropenem, or doripenem, by standard susceptibility testing methods or by a positive result for any method
FDA-approved for carbapenemase detection from specific specimen sources.

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MDR-Acinetobacter: Any Acinetobacter spp. testing non-susceptible (i.e., resistant or intermediate) to at
least one agent in at least 3 antimicrobial classes of the following 6 antimicrobial classes:
β-lactam/β-lactam
β-lactamase inhibitor
combination
Piperacillin
Piperacillin/tazobactam
Cephalosporins
Cefepime
Ceftazidime

Aminoglycosides

Carbapenems

Fluoroquinolones

Amikacin
Gentamicin
Tobramycin

Imipenem
Meropenem
Doripenem

Ciprofloxacin
Levofloxacin

Sulbactam
Ampicillin/sulbactam

Settings: MDRO LabID Event reporting can occur in any location: inpatient or outpatient.
Requirements: Facilities choose at least 1 of the reporting methods listed below and report data
accordingly:
Method
Facility-wide by location
Selected locations

Overall Facility-wide
Inpatient (FacWideIN)

Overall Facility-wide
Outpatient (FacWideOUT)
Overall Facility-wide
Inpatient, Blood Specimens
Only
Overall Facility-wide
Outpatient, Blood Specimens
Only

Numerator Data Reporting
Enter each MDRO LabID Event
from all locations separately
Enter each MDRO LabID Event
from selected locations separately

Denominator Data Reporting
Report separate denominators for
each location in the facility
Report separate denominators for
each location monitored as
specified in the NHSN Monthly
Reporting Plan
Enter each MDRO LabID Event
Report only one denominator for
from all inpatient locations
the entire facility (e.g., total
separately
number of admissions and total
number of patient days)
Enter each MDRO LabID Event
Report only one denominator for
from all outpatient locations
all outpatient locations (e.g., total
separately
number of encounters)
Enter each MDRO LabID Blood
Report only one denominator for
Specimen Event from all inpatient the entire facility (e.g., total
locations separately
number of admissions and total
number of patient days)
Enter each MDRO LabID Blood
Report only one denominator for
Specimen Event from all
all outpatient locations (e.g., total
outpatient locations separately
number of encounters)

NOTE: Facilities must indicate each reporting choice chosen for the calendar month on the Patient Safety
Monthly Reporting Plan (CDC 57.106).

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For each MDRO being monitored, all MDRO test results are evaluated using either the algorithm in Figure
1 (All Specimens) or Figure 2 (Blood Specimens only) to determine reportable LabID events for each
calendar month, for each facility location as determined by the reporting method chosen. If monitoring all
specimens, all first MDRO isolates (chronologically) per patient, per month, per location are reported as a
LabID event regardless of specimen source (EXCLUDES tests related to active surveillance testing) (Figure
1); if a duplicate MDRO isolate is from blood, or if monitoring blood specimens only, it is reported as a
LabID event only if it represents a unique blood source [i.e., no prior isolation of the MDRO in blood from
the same patient and location in ≤2 weeks, even across calendar months] (Figures 1 & 2). As a general rule,
at a maximum, there should be no more than 3 blood isolates reported, which would be very rare. If
monitoring all specimens and a blood isolate is entered as the first specimen of the month, then no nonblood specimens can be entered that month for that patient and location. Report each LabID Event
individually on a separate form.
Definitions:
MDRO Isolate: Any specimen, obtained for clinical decision making, testing positive for an MDRO (as
defined above). NOTE: Excludes tests related to active surveillance testing.
Duplicate MDRO Isolate: If monitoring all specimens, any MDRO isolate from the same patient and
location after an initial isolation of the specific MDRO during a calendar month, regardless of specimen
source, except unique blood source (Figure 1).
EXAMPLE: On January 2, a newly admitted ICU patient has a positive MRSA urine culture. The
following week, while still in the ICU, the same patient has MRSA cultured from an infected
decubitus ulcer. The MRSA wound culture is considered a duplicate MDRO isolate, since it is the
second non-blood MRSA isolate collected from the same patient and location during the same
calendar month.
Unique Blood Source: For this organism and location an MDRO isolate from blood in a patient with no
prior positive blood culture for the same MDRO and location in ≤2 weeks, even across calendar months
(Figure 2) and if following all specimens the first MDRO for the patient, month, and location has already
been reported. There should be a full 14 days with no positive blood culture result from the laboratory for
the patient, MDRO, and location before another Blood LabID Event is entered into NHSN for the patient,
MDRO, and location. NOTE: The date of specimen collection is considered Day 1.
EXAMPLE: On January 1, an ICU patient has a positive MRSA blood culture which is entered into
NHSN. On January 4, while in the same location (ICU), the same patient has another positive
MRSA blood culture which is not entered into NHSN because it has not been 14 days since the
original positive MRSA blood culture while in the same location. On January 16, while in the same
location (ICU), the same patient has another positive MRSA blood culture. While it has been more
than 14 days since the initial positive MRSA blood culture from the same patient and location was
entered into NHSN (January 1), it has not been >14 days since the patient’s most recent positive
MRSA blood culture (January 4) while in the same location. Therefore, the positive blood culture for
January 16 is not entered into NHSN. On January 31, the patient has another positive MRSA blood

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culture while in the same location (ICU). Since it has been >14 days since the patient’s most recent
positive culture (January 16) while in the same location, this event is entered into NHSN.
Laboratory-Identified (LabID) Event: All non-duplicate MDRO isolates from any specimen source and
unique blood source MDRO isolates, including specimens collected in the facility’s own emergency
department (ED) or affiliated outpatient clinic visit, if collected the same calendar day as patient admission
[EXCLUDES tests related to active surveillance testing] (See Figures 1 & 2). Even if reporting at the
FacWide level, all reporting must follow rules by location for reporting.
EXAMPLE: If monitoring all specimens, on January 2, a newly admitted ICU patient with no
previously positive laboratory isolates during this admission has a positive MRSA urine culture. This
specimen represents a LabID Event since it is the first MRSA isolate for the patient, the location,
and the calendar month.
EXAMPLE: If monitoring all specimens, on January 2, a VRE culture is collected from an ED
patient’s wound at 05:00. The patient is then admitted to 4W on the same calendar day. The ED
culture result may be entered as the inpatient LabID event for the 4W location for January 2, since
the patient was admitted on the same calendar day.
EXAMPLE: If monitoring blood specimens only, on January 26, a newly admitted ICU patient with
no previously positive laboratory isolates during this admission has a positive MRSA urine culture
which is not entered as a LabID Events since blood specimens only are being monitored. The
following day, while in the same location, the same patient has a positive MRSA blood culture. This
specimen represents a LabID Event since it is a unique blood source (the first MRSA blood isolate
for the same patient and same location). While remaining in ICU, the same patient has another
positive blood culture on February 5. This does not represent a new LabID Event since it has not
been >14 days since the most recent MRSA positive blood isolate for this patient and location.
Reporting Instructions: All LabID Events must be reported separately and independently of Events
reported through MDRO Infection Surveillance reporting and/or HAIs reported through the Deviceassociated and/or Procedure-associated Modules. See Appendix 1. Guidance for Handling MDRO and CDI
Module Infection Surveillance and LabID Event Reporting When Also Following Other NHSN Modules for
instructions on unique reporting scenarios.
Numerator Data: Data will be reported using the Laboratory-identified MDRO or CDI Event form (CDC
57.128).
Denominator Data: Patient days, admissions (for inpatient locations), and encounters for emergency
department and other affiliated outpatient locations are reported using the MDRO and CDI Prevention
Process and Outcome Measures Monthly Monitoring form (CDC 57.127). See Tables of Instructions for
completion instructions. An encounter is defined as a patient visit to an outpatient location. When
determining a patient’s admission dates to both the facility and specific inpatient location, the NHSN user
must take into account all such days, including any days spent in an inpatient location as an “observation”
patient before being officially admitted as an inpatient to the facility, as these days contribute to exposure

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risk. Therefore, all such days are included in the counts of admissions and patient days for the facility and
specific location; facility and specific location admission dates must be moved back to the first day spent in
the inpatient location. For further information on counting patient days and admissions, see Appendix 2.
Data Analysis: Based on data provided on the LabID Event form, each event will be categorized by NHSN
to populate different measures. By classifying positive cultures obtained on day 1 (admission date), day 2,
and day 3 of admission as CO LabID Events and positive cultures obtained on or after day 4 as HO LabID
Events, all HO LabID Events will have occurred more than 48 hours after admission.
The following categorizations and prevalence and incidence calculations are built into the analysis
capabilities of NHSN, and are based on timing of admission to a facility and/or location, specimen
collection, and location where specimen was collected. Descriptions are provided to explain how the
categories and metrics are defined in NHSN.
Categorizing MDRO LabID Events – Based on Date Admitted to Facility and Date Specimen Collected:
Community-Onset (CO): LabID Event specimen collected as an outpatient or an inpatient ≤3 days after
admission to the facility (i.e., days 1, 2, or 3 of admission).
Healthcare Facility-Onset (HO): LabID Event specimen collected >3 days after admission to the facility
(i.e., on or after day 4).
MRSA Bloodstream Infection Standardized Infection Ratio (SIR):
The SIR is calculated by dividing the number of observed events by the number of expected events. The
number of expected infections, in the context of statistical prediction, is calculated using LabID probabilities
estimated from multivariate logistic regression models constructed from NHSN data during a baseline time
period, which represents standard populations. MRSA Bloodstream Infection SIRs are calculated for
FacWideIN surveillance only.
NOTE: The SIR will be calculated only if the number of expected events (numExp) is ≥1.
Facility MRSA Bloodstream Infection Incidence SIR = Number of all unique blood source LabID Events
identified >3 days after admission to the facility (i.e., HO events, when monitoring by overall facility-wide
inpatient = FacWideIN) / Number of expected HO MRSA blood LabID Events
Proxy Measures for Exposure Burden of MDROs – All specimens:
Inpatient Reporting:
• Admission Prevalence Rate = Number of 1st LabID Events per patient per month identified ≤3 days
after admission to the location (if monitoring by inpatient location), or the facility (if monitoring by
overall facility-wide inpatient=FacWideIN) / Number of patient admissions to the location or facility
x 100

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•

Location Percent Admission Prevalence that is Community-Onset = Number of Admission
Prevalent LabID Events to a location that are CO / Total number Admission Prevalent LabID Events
x 100

•

Location Percent Admission Prevalence that is Healthcare Facility-Onset = Number of Admission
Prevalent LabID Events to a location that are HO / Total number of Admission Prevalent LabID
Events x 100

•

Overall Patient Prevalence Rate = Number of 1st LabID Events per patient per month regardless of
time spent in location (i.e., prevalent + incident, if monitoring by inpatient location), or facility (i.e.,
CO + HO, if monitoring by overall facility-wide inpatient=FacWideIN) / Number of patient
admissions to the location or facility x 100

Outpatient Reporting:
• Outpatient Prevalence Rate = Number of 1st LabID Events per patient per month for the location (if
monitoring by outpatient location), or the facility (if monitoring by overall facility-wide outpatient =
FacWideOUT) / Number of patient encounters for the location or facility x 100
Measures for MDRO Bloodstream Infection: Calculated when monitoring either all specimens or Blood
specimens only. NOTE: the Blood specimen’s only option can only be used at the FacWideIN and
FacWideOUT levels.
Inpatient Reporting:
• MDRO Bloodstream Infection Admission Prevalence Rate = Number of all unique blood source
LabID Events per patient per month identified ≤3 days after admission to the location (if monitoring
by inpatient location), or facility (if monitoring by overall facility-wide inpatient=FacWideIN)/
Number of patient admissions to the location or facility x 100
•

MDRO Bloodstream Infection Incidence Rate = Number of all unique blood source LabID Events
per patient per month identified >3 days after admission to the location (if monitoring by inpatient
location), or facility (if monitoring by overall facility-wide inpatient=FacWideIN) / Number of
patient admissions to the location or facility x 100 (will be removed from NHSN analysis in July
2013)

•

MDRO Bloodstream Infection Incidence Density Rate = Number of all unique blood source LabID
Events per patient per month identified >3 days after admission to the location (if monitoring by
inpatient location), or facility (if monitoring by overall facility-wide inpatient=FacWideIN) /
Number of patient days for the location or facility x 1,000 (will be referred to in NHSN analysis as
Incidence Rate after July 2013)

•

MDRO Bloodstream Infection Overall Patient Prevalence Rate = Number of 1st Blood LabID Events
per patient per month regardless of time spent in location (i.e., prevalent + incident, if monitoring by
inpatient location), or facility (i.e., CO + HO, if monitoring by overall facility-wide
inpatient=FacWideIN) / Number of patient admissions to the location or facility x 100

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Outpatient Reporting:
• MDRO Bloodstream Infection Outpatient Prevalence Rate = Number of all unique blood source
LabID Events per patient per month for the location (if monitoring by outpatient location), or the
facility (if monitoring by overall facility-wide outpatient=FacWideOUT) / Number of patient
encounters for the location or facility x 100
Proxy Measures for MDRO Healthcare Acquisition:
•

Overall MDRO Infection/Colonization Incidence Rate = Number of 1st LabID Events per patient per
month among those with no documented prior evidence of previous infection or colonization with
this specific organism type from a previously reported LabID Event, and identified >3 days after
admission to the location (if monitoring by inpatient location), or facility (if monitoring by overall
facility-wide inpatient=FacWideIN) / Number of patient admissions to the location or facility x 100
(will be removed from NHSN analysis in July 2013)

•

Overall MDRO Infection/Colonization Incidence Density Rate = Number of 1st LabID Events per
patient per month among those with no documented prior evidence of previous infection or
colonization with this specific organism type from a previously reported LabID Event, and identified
>3 days after admission to the location (if monitoring by inpatient location), or facility (if monitoring
by overall facility-wide inpatient=FacWideIN) / Number of patient days for the location or facility x
1,000 (will be referred to in NHSN analysis as Incidence Rate after July 2013)

B. Clostridium difficile (C. difficile) LabID Event Reporting
Methodology: Facilities may choose to monitor C. difficile where C. difficile testing in the laboratory is
performed routinely only on unformed (i.e., conforming to the shape of the container) stool samples. C.
difficile LabID events may be monitored from all available inpatient locations as well as all available
affiliated outpatient locations where care is provided to patients post discharge or prior to admission (e.g.,
emergency departments, outpatient clinics, and physician offices that submit samples to the facility’s
laboratory).
Settings: C. difficile LabID Event reporting can occur in any location: inpatient or outpatient. Surveillance
will NOT be performed in NICU, SCN, babies in LDRP, well-baby nurseries, or well-baby clinics. If LDRP
locations are being monitored, baby counts must be removed.

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Requirements: Facilities must choose one or more of the reporting choices listed below and report data
accordingly:
Method
Facility-wide by location
Selected locations

Numerator Data Reporting
Enter each CDI LabID Event
from all locations separately
Enter each CDI LabID Event
from selected locations separately

Overall Facility-wide
Inpatient (FacWideIN)

Enter each CDI LabID Event
from all inpatient locations
separately

Overall Facility-wide
Outpatient (FacWideOUT)

Enter each CDI LabID Event
from all outpatient locations
separately

Denominator Data Reporting
Report separate denominators for
each location in the facility
Report separate denominators for
each location monitored as
specified in the NHSN Monthly
Reporting Plan
Report only one denominator for
the entire facility (e.g., total
number of admissions and total
number of patient days)
Report only one denominator for
all outpatient locations (e.g., total
number of encounters)

NOTE: Facilities must indicate each reporting choice chosen for the calendar month on the Patient Safety
Monthly Reporting Plan (CDC 57.106).
Definitions:
CDI-positive laboratory assay:
A positive laboratory test result for C. difficile toxin A and/or B, (includes molecular assays [PCR] and/or
toxin assays)
OR
A toxin-producing C. difficile organism detected by culture or other laboratory means performed on a stool
sample.
Duplicate C. difficile-positive test: Any C. difficile toxin-positive laboratory result from the same patient
and location, following a previous C. difficile toxin-positive laboratory result within the past two weeks (14
days) (even across calendar months). There should be a full 14 days with no C. difficile toxin-positive
laboratory result for the patient and location, before another C. difficile LabID Event is entered into NHSN
for the patient and location. The date of specimen collection is considered Day 1.
EXAMPLE: On January 1, an ICU patient has a C. difficile toxin-positive laboratory result which is entered
into NHSN. On January 4, while in the same location (ICU), the same patient has another positive C.
difficile toxin-positive laboratory result which is not entered into NHSN because it has not been >14 days
since the original C. difficile toxin-positive laboratory result while in the same location. On January 16,
while in the same location (ICU), the same patient has another C. difficile toxin-positive laboratory result.
While it has been more than 14 days since the initial positive C. difficile toxin-positive laboratory result was
entered into NHSN (January 1) for the same patient and same location, it has not been >14 days since the
patient’s most recent C. difficile toxin-positive laboratory result (January 4) while in the same location.

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Therefore, the C. difficile toxin-positive laboratory result for January 16 is not entered into NHSN. On
January 31, the patient has another C. difficile toxin-positive laboratory result while in the same location
(ICU). Since it has been >14 days since the patient’s most recent C. difficile toxin-positive laboratory result
(January 16) while in the same location, this event is entered into NHSN.
Laboratory-Identified (LabID) Event: All non-duplicate C. difficile toxin-positive laboratory results. Can
include specimens collected in the Emergency Department of the admitting facility or other affiliated
outpatient location, if collected same calendar day as patient admission (See Figure 3). Even if reporting at
the FacWide level, all reporting must follow rules by location for reporting.
Reporting Instructions: All C. difficile LabID Events must be reported separately and independently of
Events reported using the C. difficile Infection Surveillance reporting option and/or HAI reporting.
Numerator: Data will be reported using the Laboratory-Identified MDRO or CDI Event form (CDC
57.128).
Denominator Data: Patient days, admissions (for inpatient locations), and encounters for emergency
department and other affiliated outpatient locations are reported using the MDRO and CDI Prevention
Process and Outcome Measures Monthly Monitoring form (CDC 57.127). See Tables of Instructions for
completion instructions. An encounter is defined as a patient visit to an outpatient location for care. When
determining a patient’s admission dates to both the facility and specific inpatient location, the NHSN user
must take into account all days, including any days spent in an inpatient location as an “observation” patient
before being officially admitted as an inpatient to the facility, as these days contribute to exposure risk.
Therefore, all such days are included in the counts of admissions and patient days for the facility and
specific location; facility and specific location admission dates must be moved back to the first day spent in
the inpatient location. For further information on counting patient days and admissions, see Appendix 2:
Determining Patient Days for Summary Data Collection: Observation vs. Inpatients
CDI Data Analysis: Based on data provided on the LabID Event form, each event will be categorized by
NHSN to populate different measures. By classifying positive cultures obtained on day 1 (admission date),
day 2, and day 3 of admission as CO LabID Events and positive cultures obtained on or after day 4 as HO
LabID Events. All HO LabID Events will have occurred more than 48 hours after admission.
The following categorizations and prevalence and incidence calculations are built into the analysis
capabilities of NHSN, and are based on timing of admission to a facility and/or location, specimen
collection, and location where specimen was collected. Descriptions are provided to explain how the
categories and metrics are defined in NHSN.

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MDRO and CDI Module

Categorization Based on Current Date Specimen Collected and Prior Date Specimen Collected of a
previous CDI LabID Event:
• Incident CDI Assay: Any CDI LabID Event from a specimen obtained >8 weeks after the most CDI
recent LabID Event (or with no previous CDI LabID Event documented) for that patient.
•

Recurrent CDI Assay: Any CDI LabID Event from a specimen obtained >2 weeks and ≤8 weeks
after the most recent CDI LabID Event for that patient.

NOTE: For Facility-wide surveillance, CDI Assay is assigned based on Events within the same setting only.
For example, when performing both FacWideIN and FacWideOUT surveillance, CDI Assay of inpatient
CDI LabID Events will be determined by a review of previously-entered CDI LabID Events from inpatient
locations only.
The incident and recurrent CDI LabID Events are further categorized within NHSN. The following
categorizations, as well as prevalence and incidence calculations are built into the analysis capabilities of
NHSN, and are based on timing of admission to facility and/or location, specimen collection, location where
specimen was collected, and previous discharge. Descriptions are provided to explain how the categories
and metrics are defined in NHSN.
Categorizing CDI LabID Events – Based on Date Admitted to Facility and Date Specimen Collected:
• Community-Onset (CO): LabID Event collected as an outpatient or an inpatient ≤3 days after
admission to the facility (i.e., days 1, 2, or 3 of admission).
•

Community-Onset Healthcare Facility-Associated (CO-HCFA): CO LabID Event collected from a
patient who was discharged from the facility ≤4 weeks prior to current date of stool specimen
collection. Data from outpatient locations (e.g., outpatient encounters) are not included in this
definition.

•

Healthcare Facility-Onset (HO): LabID Event collected >3 days after admission to the facility (i.e.,
on or after day 4).

CDI Standardized Infection Ratio (SIR):
The SIR is calculated by dividing the number of observed events by the number of expected events. The
number of expected infections, in the context of statistical prediction, is calculated using LabID probabilities
estimated from multivariate logistic regression models constructed from NHSN data during a baseline time
period, which represents standard populations. CDI SIRs are calculated for FacWideIn surveillance only.
NOTE: The SIR will be calculated only if the number of expected events (numExp) is ≥1.
Facility CDI Incidence SIR = Number of all Incident CDI LabID Events identified >3 days after admission
to the facility (i.e., HO events when monitoring by overall facility-wide inpatient = FacWideIN) / Number
of expected Incident HO CDI LabID Events

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MDRO and CDI Module

Calculated CDI Prevalence Rates:
Inpatient Reporting:
• Admission Prevalence Rate = Number of non-duplicate CDI LabID Events per patient per month
identified ≤3 days after admission to the location (if monitoring by inpatient location), or facility (if
monitoring by overall facility-wide inpatient=FacWideIN) (includes CO and CO-HCFA events) /
Number of patient admissions to the location or facility x 100
•

Community-Onset Admission Prevalence Rate = Number of CDI LabID events that are CO, per
month, in the facility / Number of patient admissions to the facility x 100 (this calculation is only
accurate for Overall Facility-wide Inpatient reporting) (will be added to NHSN analysis in July
2013)

•

Location Percent Admission Prevalence that is Community-Onset = Number of Admission
Prevalent LabID Events to a location that are CO / Total number Admission Prevalent LabID Events
x 100 (Note: The numerator in this formula does not include Admission Prevalent LabID Events
that are CO-HFCA.)

•

Location Percent Admission Prevalence that is Community-Onset Healthcare Facility-Associated =
Number of Admission Prevalent LabID Events to a location that are CO-HCFA / Total number
Admission Prevalent LabID Events x 100

•

Location Percent Admission Prevalence that is Healthcare Facility-Onset = Number of Admission
Prevalent LabID Events to a location that are HO / Total number of Admission Prevalent LabID
Events x 100

•

Overall Patient Prevalence Rate = Number of 1st CDI LabID Events per patient per month regardless
of time spent in location (i.e., prevalent + incident, if monitoring by inpatient location), or facility
(i.e., CO + CO-HCFA + HO, if monitoring by overall facility-wide inpatient=FacWideIN) / Number
of patient admissions to the location or facility x 100

Outpatient Reporting:
• Outpatient Prevalence Rate = Number of all non-duplicate CDI LabID Events per patient per month
for the location (if monitoring by outpatient location), or the facility (if monitoring by overall
facility-wide outpatient=FacWideOUT) / Number of patient encounters for the location or facility x
100
Calculated CDI Incidence Rates: (see categorization of Incident, HO, and CO-HCFA above).
•

Location CDI Incidence Rate = Number of Incident CDI LabID Events per month identified >3 days
after admission to the location / Number of patient days for the location x 10,000

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MDRO and CDI Module

•

Facility CDI Healthcare Facility-Onset Incidence Rate = Number of all Incident HO CDI LabID
Events per month in the facility/ Number of patient days for the facility x 10,000 (this calculation is
only accurate for Overall Facility-wide Inpatient reporting)

•

Facility CDI Combined Incidence Rate = Number of all Incident HO and CO-HCFA CDI LabID
Events per month in the facility / Number of patient days for the facility x 10,000 (this calculation is
only accurate for Overall Facility-wide Inpatient reporting)

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MDRO and CDI Module

Figure 1. MDRO Test Result Algorithm for All Specimens Laboratory-Identified (LabID) Events
MDRO isolate from any specimen (except AST
specimens) per patient and location

1st in calendar
month per
patient, per
location, per
MDRO

Yes

LabID Event
(Non-duplicate
isolate)

No

Duplicate MDRO
isolate

Source =
Blood for
patient
and same
location

No
Not a
LabID
Event

Yes

Prior (+) same
MDRO from blood
in ≤2 weeks from
same location
(including across
calendar months)

No
LabID Event (Unique blood
source MDRO)

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Yes

Not a
LabID
Event

MDRO and CDI Module

Figure 2. MDRO Test Result Algorithm for Blood Specimens Only Laboratory-Identified (LabID) Events

MDRO isolate from blood per
patient and location

No

Prior (+) same
MDRO from
blood in ≤2 weeks
from same patient
and location
(including across
calendar months)

Duplicate
MDRO test

LabID Event

January 2013

Yes

12 - 18

Not a LabID
Event

MDRO and CDI Module

Figure 3. C. difficile Test Result Algorithm for Laboratory Identified (LabID) Events

(+) C. difficile test result
per patient and location

Prior (+) in ≤2
weeks from same
patient and
location
(including across
calendar months)
No

Yes

Duplicate C.
difficile test

LabID Event

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Not a LabID
Event

MDRO and CDI Module

Option 2: Infection Surveillance Reporting
Introduction: The Infection Surveillance reporting option for MDRO and C. difficile infections enables
users to utilize the CDC/NHSN healthcare-associated infections definitions for identifying and reporting
infections associated with MDROs and/or C. difficile. Surveillance must occur from at least one patient care
area and requires active, patient-based, prospective surveillance of the chosen MDRO(s) and/or C. difficile
infections (CDIs) by a trained Infection Preventionists (IP). This means that the IP shall seek to confirm
and classify infections caused by the chosen MDRO(s) and/or C. difficile for monitoring during a patient’s
stay in at least one patient care location during the surveillance period. These data will enhance the ability of
NHSN to aggregate national data on MDROs and CDIs.
A. MDRO Infection Surveillance Reporting
Methodology: Facilities may choose to monitor one or more of the following MDROs: MRSA, MRSA and
MSSA, VRE, CephR- Klebsiella spp., CRE-Klebsiella spp., CRE-E. coli, and multidrug-resistant
Acinetobacter spp. (See definitions in Section I, Option 1A). For S. aureus, both the resistant (MRSA) and
the susceptible (MSSA) phenotypes can be tracked to provide concurrent measures of the susceptible
pathogens as a comparison to those of the resistant pathogens in a setting of active MRSA prevention
efforts. REMEMBER: No Active Surveillance Culture/Testing (ASC/AST) results are to be included in this
reporting of individual results.
Settings: Infection Surveillance can occur in any inpatient location where such infections may be identified
and where denominator data can be collected, which may include critical/intensive care units (ICU),
specialty care areas (SCA), neonatal units, step-down units, wards, and chronic care units. In Labor,
Delivery, Recovery, & Post-partum (LDRP) locations, where mom and babies are housed together, users
must count both mom and baby in the denominator. If moms only are being counted, then multiply moms
times two to include both mom and baby in denominators.
Requirements: Surveillance for all types of NHSN-defined healthcare-associated infections (HAIs) of the
MDRO selected for monitoring in at least one location in the healthcare facility as indicated in the Patient
Safety Monthly Reporting Plan (CDC 57.106).
Definitions: MDROs included in this module are defined in Section I, Option 1A. Refer to CDC/NHSN
Surveillance Definition of Healthcare-Associated Infection and Criteria for Specific Types of Infections in
the Acute Care Setting for HAI for infection site criteria. Refer to Key Terms chapter for assistance with
variable definitions.
Location of Attribution and Transfer Rule applies – See Key Terms chapter.
Reporting Instructions: If participating in MDRO/CDI Infection Surveillance and/or LabID Event
Reporting, along with the reporting of HAIs through the Device-Associated and/or Procedure-Associated
Modules, see Appendix 1: Guidance for Handling MDRO/CDI Module Infection Surveillance and LabID
Event Reporting When Also Following Other NHSN Modules, for instructions on unique reporting scenarios.

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MDRO and CDI Module

Numerator Data: Number of healthcare-associated infections, by MDRO type. Infections are reported on
the appropriate NHSN forms: Primary Bloodstream Infection, Pneumonia, Ventilator-Associated Event,
Urinary Tract Infection, Surgical Site Infection, or MDRO or CDI Infection Event (CDC 57.108, 57.111,
57.112, 57.114, 57.120, and 57.126, respectively.). See the Tables of Instructions, located in each of the
applicable chapters, for completion instructions.
Denominator Data: Number of patient days and admissions. Patient days and admissions are reported by
location using the MDRO and CDI Prevention Process and Outcome Measures Monthly Monitoring form
(CDC 57.127). See Tables of Instructions for completion instructions.
Data Analysis: Data are stratified by time (e.g., month, quarter, etc.) and patient care location.
MDRO Infection Incidence Rate = Number of HAIs by MDRO type/ Number of patient days x 1000
B. Clostridium difficile Infection Surveillance Reporting
Methodology: C. difficile Infection (CDI) Surveillance, reporting on all NHSN-defined healthcareassociated CDIs from at least one patient care area, is one reporting option for C. difficile (i.e., part of your
facility’s Monthly Reporting Plan). These data will enhance the ability of NHSN to aggregate national data
on CDIs.
Settings: Infection Surveillance will occur in any inpatient location where denominator data can be
collected, which may include critical/intensive care units (ICU), specialty care areas (SCA), step-down
units, wards, and chronic care units. Surveillance will NOT be performed in Neonatal Intensive Care Units
(NICU), Specialty Care Nurseries (SCN), babies in LDRP, or well-baby nurseries. If LDRP locations are
being monitored, baby counts must be removed.
Requirements: Surveillance for CDI must be performed in at least one location in the healthcare institution
as indicated in the Patient Safety Monthly Reporting Plan (CDC 57.106).
Definitions: Report all healthcare-associated infections where C. difficile, identified by a positive toxin
result, including toxin producing gene [PCR]) is the associated pathogen. Refer to specific definitions in
CDC/NHSN Surveillance Definition of Healthcare-Associated Infection and Criteria for Specific Types of
Infections in the Acute Care Setting chapter for gastroenteritis (GI-GE), and gastrointestinal tract (GI-GIT)
infections criteria.
HAI cases of CDI (i.e., C. difficile pathogen identified with a positive toxin result, including toxin
producing gene [PCR]) that meet criteria for a healthcare-associated infection should be reported as
gastroenteritis (GI-GE) or gastrointestinal tract (GI-GIT) infections, whichever is appropriate. Report the
pathogen as C. difficile on the MDRO or CDI Infection Event form (CDC 57.126). If the patient develops
both GI-GE and GI-GIT CDI, report only GI-GIT using the date of Event as that of GI-GE CDI. This CDI
HAI reporting corresponds to surveillance for healthcare-onset, healthcare facility-associated CDI in
recently published recommendations3, which is considered the minimum surveillance for CDI.

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MDRO and CDI Module

CDI Complications: CDI in a case patient within 30 days after CDI symptom onset with at least one of the
following:
1. Admission to an intensive care unit for complications associated with CDI (e.g., for shock that
requires vasopressor therapy);
2. Surgery (e.g., colectomy) for toxic megacolon, perforation, or refractory colitis
AND/OR
3. Death caused by CDI within 30 days after symptom onset and occurring during the hospital
admission.
Location of Attribution and Transfer Rule applies – See Key Terms chapter.
Numerator Data: Number of healthcare-associated C. difficile infections. Infections are reported on the
MDRO or CDI Infection Event form (CDC 57.126). See Tables of Instructions for completion instructions.
Denominator Data: Number of patient days and admissions by location are reported using the MDRO and
CDI and Outcome Measures Monthly Monitoring form (CDC 57.127). See Tables of Instructions for
completion instructions.
C. difficile Infections:
Numerator: The total number of HAI CDI cases identified during the surveillance month for a
location.
Denominator: The total number of patient days and admissions during the surveillance month for a
location.

Data Analysis: Data are stratified by time (e.g., month, quarter, etc.) and by patient care location.
C. difficile Infection Incidence Rate = Number of HAI CDI cases / Number of patient days x 10,000

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MDRO and CDI Module

II.

Supplemental Reporting

1. Prevention Process Measures Surveillance
a. Monitoring Adherence to Hand Hygiene
Introduction: This option will allow facilities to monitor adherence to hand hygiene after a healthcare
worker (HCW) has contact with a patient or inanimate objects in the immediate vicinity of the patient.
Research studies have reported data suggesting that improved after-contact hand hygiene is associated with
reduced MDRO transmission. While there are multiple opportunities for hand hygiene during patient care,
for the purpose of this option, only hand hygiene after contact with a patient or inanimate objects in the
immediate vicinity of the patient will be observed and reported. (http://www.cdc.gov/handhygiene/)
Settings: Surveillance will occur in any location: inpatient or outpatient.
Requirements: Surveillance for adherence to hand hygiene in at least one location in the healthcare
institution for at least one calendar month as indicated in the Patient Safety Monthly Reporting Plan (CDC
57.106). This should be done in patient care locations also selected for Infection Surveillance or LabID
Event reporting.
In participating patient care locations, perform at least 30 different unannounced observations after contact
with patients for as many individual HCWs as possible. For example, try to observe all types of HCWs
performing a variety of patient care tasks during the course of the month, not only nurses, or not only during
catheter or wound care. No personal identifiers will be collected or reported.
Definitions:
Antiseptic handwash: Washing hands with water and soap or other detergents containing an antiseptic
agent.
Antiseptic hand-rub: Applying an antiseptic hand-rub product to all surfaces of the hands to reduce the
number of microorganisms present.
Hand hygiene: A general term that applies to either: handwashing, antiseptic hand wash, antiseptic hand
rub, or surgical hand antisepsis.
Handwashing: Washing hands with plain (i.e., non-antimicrobial) soap and water.
Numerator: Hand Hygiene Performed = Total number of observed contacts during which a HCW touched
either the patient or inanimate objects in the immediate vicinity of the patient and appropriate hand hygiene
was performed.
Denominator: Hand Hygiene Indicated = Total number of observed contacts during which a HCW touched
either the patient or inanimate objects in the immediate vicinity of the patient and therefore, appropriate
hand hygiene was indicated.

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MDRO and CDI Module

Hand hygiene process measure data are reported using the MDRO and CDI Prevention Process and
Outcome Measures Monthly Monitoring form (CDC 57. 127). See Tables of Instructions for completion
instructions.
Data Analysis: Data are stratified by time (e.g., month, quarter, etc.) and patient care location.
Hand Hygiene Percent Adherence = Number of contacts for which hand hygiene was performed / Number
of contacts for which hand hygiene was indicated x 100
b. Monitoring Adherence to Gown and Gloves Use as Part of Contact Precautions
Introduction: This option will allow facilities to monitor adherence to gown and gloves use when a HCW
has contact with a patient or inanimate objects in the immediate vicinity of the patient, when that patient is
on Transmission-based Contact Precautions. While numerous aspects of adherence to Contact Precautions
could be monitored, this surveillance option is only focused on the use of gown and gloves.
(http://www.cdc.gov/ncidod/dhqp/gl_isolation_contact.html)
Settings: Surveillance can occur in any of 4 types of inpatient locations: (1) intensive care units (ICU), (2)
specialty care areas, (3) neonatal intensive care units (NICU), and (4) any other inpatient care location in the
institution (e.g., surgical wards).
Requirements: Surveillance for adherence to gown and gloves use in at least one location in the healthcare
institution for at least 1 calendar month as indicated in the Patient Safety Monthly Reporting Plan (CDC
57.106). Ideally, this should be done in patient care locations also selected for Infection Surveillance or
LabID Event reporting.
Among patients on Transmission-based Contact Precautions in participating patient care locations, perform
at least 30 unannounced observations. A total of thirty different contacts must be observed monthly among
HCWs of varied occupation types. For example, try to observe all types of HCWs performing a variety of
patient care tasks during the course of the month, not only nurses, or not only during catheter or wound care.
Both gown and gloves must be donned appropriately prior to contact for compliance. No personal
identifiers will be collected or reported.
Definitions:
Gown and gloves use: In the context of Transmission-based Contact Precautions, the donning of both a
gown and gloves prior to contact with a patient or inanimate objects in the immediate vicinity of the patient.
Both a gown and gloves must be donned appropriately prior to contact for compliance.
Numerator: Gown and Gloves Used = Total number of observed contacts between a HCW and a patient or
inanimate objects in the immediate vicinity of a patient on Transmission-based Contact Precautions for
which gown and gloves had been donned appropriately prior to the contact.

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MDRO and CDI Module

Denominator: Gown and Gloves Indicated = Total number of observed contacts between a HCW and a
patient on Transmission-based Contact Precautions or inanimate objects in the immediate vicinity of the
patient and therefore, gown and gloves were indicated.
Gown and gloves use process measure data are reported using the MDRO and CDI Prevention Process and
Outcome Measures Monthly Monitoring form (CDC 57.127). See Tables of Instructions for completion
instructions.
Data Analysis: Data are stratified by time (e.g., month, quarter, etc.) and patient care location.
Gown and Glove Use Percent Adherence = Number of contacts for which gown and gloves were used
appropriately / Number of contacts for which gown and gloves were indicated x 100
c. Monitoring Adherence to Active Surveillance Testing
Introduction: This option will allow facilities to monitor adherence to active surveillance testing (AST) of
MRSA and/or VRE, using culturing or other methods.
Settings: Surveillance will occur in any of 4 types of inpatient locations: (1) intensive care units (ICU),
(2) specialty care areas, (3) neonatal intensive care units (NICU), and (4) any other inpatient care location in
the institution (e.g., surgical wards).
Requirements: Surveillance of AST adherence in at least one location in the healthcare facility for at least
one calendar month as indicated in the Patient Safety Monthly Reporting Plan (CDC 57.106). A facility may
choose to report AST for MRSA and/or VRE in one or multiple patient care locations, as the facility deems
appropriate. Ideally, this should be done in patient care locations also selected for Infection Surveillance or
LabID Event reporting. To improve standardization of timing rules for AST specimen collection, classify
admission specimens as those obtained on day 1 (admission date), day 2, or day 3 (i.e., ≤3 days). Classify
discharge/transfer AST specimens as those collected on or after day 4 (i.e., >3 days).
Definitions:
AST Eligible Patients: Choose one of two methods for identifying patients that are eligible for AST:
All = All patients in the selected patient care area regardless of history of MRSA or VRE infection
or colonization.
OR
NHx = All patients in the selected patient care area who have NO documented positive MRSA or
VRE infection or colonization during the previous 12 months (as ascertained by either a facility’s
laboratory records or information provided by referring facilities); and no evidence of MRSA or
VRE during stay in the patient care location (i.e., they are not in Contact Precautions).
Timing of AST: Choose one of two methods for reporting the timing of AST:
Adm = Specimens for AST obtained ≤3 days after admission,
OR
Both = Specimens for AST obtained ≤3 days after admission and, for patients’ stays of >3 days, at
the time of discharge/transfer. Discharge/transfer AST should include all discharges (including

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MDRO and CDI Module

discharges from the facility or to other wards or deaths) and can include the most recent weekly AST
if performed >3 days after admission to the patient care location. Discharge/transfer AST should not
be performed on patients who tested positive on AST admission.
Numerator and Denominator Data: Use the MDRO and CDI Prevention Process and Outcome Measures
Monthly Monitoring form (CDC 57.127) to indicate: 1) AST was performed during the month for MRSA
and/or VRE, 2) AST-eligible patients, and 3) the timing of AST. No personal identifiers will be collected or
reported. See Tables of Instructions for completion instructions.
Numerator: For each month during which AST is performed:
Admission AST Performed = Number of patients eligible for admission AST who had a specimen
obtained for testing ≤3 days after admission,
AND/OR
Discharge/Transfer AST Performed = For patients’ stays >3 days, the number of discharged or
transferred patients eligible for AST who had a specimen obtained for testing prior to discharge, not
including the admission AST.
Denominator: For each month during which AST is performed:
Admission AST Eligible = Number of patients eligible for admission AST (All or NHx),
AND/OR
Discharge/Transfer AST Eligible = Number of patients eligible for discharge/transfer AST (All or
NHx) AND in the facility location >3 days AND negative if tested on admission.
Data Analysis: Data are stratified by patient care location and time (e.g., month, quarter, etc.), according to
AST-eligible patients monitored and the timing of AST.
Admission AST Percent Adherence = Number of patients with admission AST Performed / Number of
patients admission AST eligible x 100
Discharge/transfer AST Percent Adherence = Number of patients with discharge/transfer AST performed /
Number of patients discharge/transfer AST eligible x 100
2. Active Surveillance Testing Outcome Measures
Introduction: This option will allow facilities to use the results of AST to monitor the prevalent and
incident rates of MRSA and/or VRE colonization or infection. This information will assist facilities in
assessing the impact of intervention programs on MRSA or VRE transmission.
Settings: Surveillance will occur in any of 4 types of inpatient locations: (1) intensive care units (ICU), (2)
specialty care, (3) neonatal intensive care units (NICU), and (4) any other inpatient care location in the
institution (e.g., surgical wards).
Requirements: Surveillance for prevalent and/or incident MRSA or VRE cases in at least one location in
the healthcare facility for at least one calendar month as indicated in the Patient Safety Monthly Reporting

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MDRO and CDI Module

Plan (CDC 57.106). This can be done ONLY in locations where AST adherence is being performed. A
minimum AST adherence level will be required for the system to calculate prevalence and incidence. A
facility may choose to report AST for MRSA and/or VRE in one or multiple patient care locations, as the
facility deems appropriate. Ideally, this should be done in patient care locations also selected for Infection
Surveillance or LabID Event reporting. To improve standardization of timing rules for AST specimen
collection, classify admission specimens as those obtained on day 1 (admission date), day 2, or day 3 (i.e.,
≤3 days). Classify discharge/transfer AST specimens as those collected on or after day 4 (i.e., >3 days).
Only the first specimen positive for MRSA or VRE from a given patient in the patient care location is
counted, whether obtained for AST or as part of clinical care. If an Admission AST specimen is not
collected from an eligible patient, assume the patient has no MRSA or VRE colonization.
Definitions:
AST Admission Prevalent case:
Known Positive = A patient with documentation on admission of MRSA or VRE colonization or
infection in the previous 12 months (i.e., patient is known to be colonized or infected as ascertained
by either a facility’s laboratory records or information provided by referring facilities). (All MRSA
or VRE colonized patients currently in a location during the month of surveillance should be
considered “Known Positive”),
OR
Admission AST or Clinical Positive = A patient with MRSA or VRE isolated from a specimen
collected for AST ≤3 days after admission or from clinical specimen obtained ≤3 days after
admission (i.e., MRSA or VRE cannot be attributed to this patient care location).
AST Incident case: A patient with a stay >3 days:
With no documentation on admission of MRSA or VRE colonization or infection during the
previous 12 months (as ascertained either by the facility’s laboratory records or information
provided by referring facilities); including admission AST or clinical culture obtained ≤3 days after
admission (i.e., patient without positive specimen),
AND
With MRSA or VRE isolated from a specimen collected for AST or clinical reasons > 3 days after
admission to the patient care location or at the time of discharge/transfer from the patient care
location (including discharges from the facility or to other locations or deaths).
MRSA colonization: Carriage of MRSA without evidence of infection (e.g., nasal swab test positive for
MRSA, without signs or symptoms of infection).
AST Eligible Patients: Choose one of two methods for identifying patients’ eligible for AST:
All = All patients in the selected patient care area regardless of history of MRSA or VRE infection
or colonization,
OR
NHx = All patients in the selected patient care area who have NO documented positive MRSA or
VRE infection or colonization during the previous 12 months (as ascertained either by the facility’s
laboratory records or information provided by referring facilities); and no evidence of MRSA or
VRE during stay in the patient care location.

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MDRO and CDI Module

Timing of AST: Choose one of two methods for reporting the timing of AST:
Adm = Specimens for AST obtained ≤3 days after admission,
OR
Both = Specimens for AST obtained ≤3 days after admission and, for patients’ stays of >3 days, at
the time of discharge/transfer. Discharge/transfer AST should include all discharges (including
discharges from the facility or to other wards or deaths) and can include the most recent weekly AST
if performed >3 days after admission to the patient care location. Discharge/transfer AST should not
be performed on patients who tested positive on AST admission.
Numerator and Denominator Data: Use the MDRO and CDI Prevention Process and Outcome Measures
Monthly Monitoring form (CDC 57.127) to indicate: 1) AST outcomes monitoring and adherence was
performed during the month for MRSA and/or VRE, 2) AST eligible patients, and 3) the timing of AST. No
personal identifiers will be collected or reported. See Tables of Instructions for completion instructions.
If only admission AST is performed, only prevalent cases of MRSA or VRE can be detected in that patient
care location. If both admission and discharge/transfer AST are performed, both prevalent and incident
cases can be detected. No personal identifiers will be collected or reported.
Admission Prevalent Case:
Numerator Sources:
• Known Positive
• Admission AST or Clinical Positive = Cases ≤3 days after admission
Denominator: Total number of admissions
Incident Case:
Numerator: Discharge/transfer AST or Clinical Positive = Cases >3 days after admission and without
positive test result(s) on admission
Denominator: Total number of patient days
NOTE: For research purposes calculating patient-days at risk (i.e., excluding patient-days in which patients
were known to be MRSA or VRE colonized or infected) may be a preferable denominator, but for
surveillance purposes and ease of aggregating, total number of patient days is required for this module.
Data Analysis: Data are stratified by patient care location and time (e.g., month, quarter, etc.) according to
the eligible patients monitored and timing of AST.
AST Admission Prevalence rate =
For Eligible patients = All:
Number of admission AST or clinical positive / Number of admissions x 100
For Eligible patients = NHx:
Number of admission AST or clinical positive + Number of known positive / Number of admissions x 100

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MDRO and CDI Module

AST Incidence rate = Number of discharge/transfer AST or clinical positive / Number of patient days x
1000

1

HICPAC, Management of Multidrug-Resistant Organisms in Healthcare Settings.
.
2

Cohen AL, et al. Infection Control and Hospital Epidemiology. Oct 2008;29:901-913.

3

McDonald LC, et al. Infect Control Hosp Epidemiol 2007; 28:140-145.

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MDRO and CDI Module

Table 2. Rates and Measures Derived from Various MDRO and CDI Protocol Surveillance Methods
Surveillance
Method
MDRO
LaboratoryIdentified
Event

Forms

Rate

Measures

Numerator:
Laboratory-Identified
MDRO or CDI Event

MRSA Bloodstream Infection
Standardized Infection Ratio (SIR):

MRSA Blood HO
FacWideIN
Standardized
Infection Ratio
(SIR)

Denominator:
MDRO and CDI
Prevention Process &
Outcome Measures
Monthly Monitoring

Facility MRSA Bloodstream Infection
Incidence SIR = Number of all unique
blood source LabID Events identified >3
days after admission to the facility (i.e., HO
events, when monitoring by overall facilitywide inpatient = FacWideIN) / Number of
expected HO MRSA blood LabID Events
NOTE: The SIR will be calculated only if
the number of expected events (numExp)
is ≥1.

Inpatient Reporting:
Admission Prevalence Rate = Number of
1st LabID Events per patient per month
identified ≤3 days after admission to the
location (if monitoring by inpatient
location), or the facility (if monitoring by
overall facility-wide inpatient=FacWideIN)
/ Number of patient admissions to the
location or facility x 100
Location Percent Admission Prevalence
that is Community-Onset = Number of
Admission Prevalent LabID Events to a
location that are CO / Total number
Admission Prevalent LabID Events x 100
Location Percent Admission Prevalence
that is Healthcare Facility-Onset = Number
of Admission Prevalent LabID Events to a
location that are HO / Total number of
Admission Prevalent LabID Events x 100

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Proxy Measures
for MDRO
Exposure Burden

MDRO and CDI Module

Surveillance Forms
Method

Rate

Measures

Overall Patient Prevalence Rate = Number
of 1st LabID Events per patient per month
regardless of time spent in location (i.e.,
prevalent + incident, if monitoring by
inpatient location), or facility (i.e., CO +
HO, if monitoring by overall facility-wide
inpatient=FacWideIN) / Number of patient
admissions to the location or facility x 100
Outpatient Reporting:
Outpatient Prevalence Rate = Number of
1st LabID Events per patient per month for
the location (if monitoring by outpatient
location), or the facility (if monitoring by
overall facility-wide outpatient =
FacWideOUT) / Number of patient
encounters for the location or facility x 100
Inpatient Reporting:
MDRO Bloodstream Infection Admission
Prevalence Rate = Number of all unique
blood source LabID Events per patient per
month identified ≤3 days after admission to
the location (if monitoring by inpatient
location), or facility (if monitoring by
overall facility-wide inpatient=FacWideIN)
/ Number of patient admissions to the
location or facility x 100
MDRO Bloodstream Infection Incidence
Rate = Number of all unique blood source
LabID Events per patient per month
identified >3 days after admission to the
location (if monitoring by inpatient
location), or facility (if monitoring by
overall facility-wide inpatient =
FacWideIN) / Number of patient days for
the location or facility x 1,000
MDRO Bloodstream Infection Overall
Patient Prevalence Rate = Number of 1st
Blood LabID Events per patient per month
regardless of time spent in location (i.e.,

January 2013

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Measures for
MDRO
Bloodstream
Infection
Admission
Prevalence and
Incidence

MDRO and CDI Module

Surveillance Forms
Method

Rate

Measures

prevalent + incident, if monitoring by
inpatient location), or facility (i.e., CO +
HO, if monitoring by overall facility-wide
inpatient=FacWideIN) / Number of patient
admissions to the location or facility x 100
Outpatient Reporting:
MDRO Bloodstream Infection Outpatient
Prevalence Rate = Number of all unique
blood source LabID Events per patient per
month for the location (if monitoring by
outpatient location), or the facility (if
monitoring by overall facility-wide
outpatient=FacWideOUT) / Number of
patient encounters for the location or
facility x 100

CDI
Laboratory
Identified
Event

Monthly Monitoring
Numerator:
Laboratory-Identified
MDRO or CDI Event
Denominator:
MDRO and CDI
Prevention Process &
Outcome Measures
Monthly Monitoring

Overall MDRO Infection/Colonization
Incidence Rate = Number of 1st LabID
Events per patient per month among those
with no documented prior evidence of a
previous LabID Event with this specific
organism type and identified >3 days after
admission to the location (if monitoring by
inpatient location), or facility (if
monitoring by overall facility-wide
inpatient=FacWideIN) / Number of patient
days for the location or facility x 1,000

Proxy Measures
for
MDRO Healthcare
Acquisition

CDI Standardized Infection Ratio (SIR):
Facility CDI Incidence SIR = Number of all
Incident CDI LabID Events identified >3
days after admission to the facility (i.e., HO
events when monitoring by overall facilitywide inpatient = FacWideIN) / Number of
expected Incident HO CDI LabID Events

CDI HO
FacWideIN
Standardized
Infection Ratio
(SIR)

NOTE: The SIR will be calculated only if
the number of expected events (numExp)
is ≥1.
_______________

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MDRO and CDI Module

Surveillance Forms
Method

Rate

Measures

Inpatient Reporting:
Admission Prevalence Rate = Number of
non-duplicate CDI LabID Events per
patient per month identified ≤3 days after
admission to the location (if monitoring by
inpatient location), or facility (if monitoring
by overall facility-wide inpatient =
FacWideIN) (includes CO and CO-HCFA
events) / Number of patient admissions to
the location or facility x 100

Proxy Measures
for
CDI Exposure
Burden

CO Admission Prevalence Rate = Number
of CDI LabID events that are CO, per
month, in the facility / Number of patient
admissions to the facility x 100 (this
calculation is only accurate for Overall
Facility-wide Inpatient reporting)
Location Percent Admission Prevalence
that is Community-Onset = Number of
Admission Prevalent LabID Events to a
location that are CO only / Total number
Admission Prevalent LabID Events x 100
Location Percent Admission Prevalence
that is Community-Onset Healthcare
Facility-Associated = Number of
Admission Prevalent LabID Events to a
location that are CO-HCFA / Total number
Admission Prevalent LabID Events x 100
Location Percent Admission Prevalence
that is Healthcare Facility-Onset = Number
of Admission Prevalent LabID Events to a
location that are HO / Total number of
Admission Prevalent LabID Events x 100
Overall Patient Prevalence Rate = Number
of 1st CDI LabID Events per patient per
month regardless of time spent in location
(i.e., prevalent + incident, if monitoring by
inpatient location), or facility (i.e., CO +

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MDRO and CDI Module

Surveillance Forms
Method

Rate

Measures

CO-HCFA + HO, if monitoring by overall
facility-wide inpatient=FacWideIN) /
Number of patient admissions to the
location or facility x 100
Outpatient Reporting:
Outpatient Prevalence Rate = Number of
all non-duplicate CDI LabID Events per
patient per month for the location (if
monitoring by outpatient location), or the
facility (if monitoring by overall facilitywide outpatient=FacWideOUT) / Number
of patient encounters for the location or
facility x 100
Location CDI Incidence Rate = Number of
Incident CDI LabID Events per month
identified >3 days after admission to the
location / Number of patient days for the
location x 10,000

Measures for CDI
Healthcare
Acquisition

Facility CDI Healthcare Facility-Onset
Incidence Rate = Number of all Incident
HO CDI LabID Events per month in the
facility/ Number of patient days for the
facility x 10,000 (this calculation is only
accurate for Overall Facility-wide Inpatient
reporting)
Facility CDI Combined Incidence Rate =
Number of all Incident HO and CO-HCFA
CDI LabID Events per month in the facility
/ Number of patient days for the facility x
10,000 (this calculation is only accurate for
Overall Facility-wide Inpatient reporting)
MDRO
Infection
Surveillance

January 2013

Numerator:
1)Primary Bloodstream
Infection
2) Pneumonia
3) VentilatorAssociated Event

Data are stratified by time (e.g., month,
year) and patient care location.
MDRO Infection Incidence Rate = Number
of healthcare-associated infections by MDRO
type/ Number of patient days x 1000

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HAI MDRO
Incidence Rate

MDRO and CDI Module

Surveillance Forms
Method
4) Urinary Tract
Infection
5) Surgical Site
Infection
6) MDRO Infection
Event

CDI
Infection
Surveillance

Denominator:
MDRO and CDI
Prevention Process &
Outcome Measures
Monthly Monitoring
Numerator:
CDI Infection Event

Rate

Measures

C. Difficile Infection Incidence Rate =
HAI CDI
Number of C. difficile healthcare-associated Incidence Rate
infections/ Number of patient days x 10,000

Denominator:
MDRO and CDI
Prevention Process &
Outcome Measures
Monthly Monitoring
Prevention
Process
Measures:
Hand
Hygiene
Gown &
Gloves Use

Active
Surveillance
Testing
(AST)
(MRSA &
VRE only)

January 2013

Numerator &
Denominator:
MDRO and CDI
Prevention Process &
Outcome Measures
Monthly Monitoring

Hand Hygiene Percent Adherence =
Number of contacts for which hand hygiene
was performed / Number of contacts for
which hand hygiene was indicated x100

Adherence
Percent:

Gown & Glove Use Percent Adherence =
Number of contacts during which gown and
gloves were used /Number of contacts for
which gown and gloves were indicated
x100.
Admission AST Percent Adherence =
Number of patients with admission AST
performed / Number of patients admission
AST eligible x100

Gown & Gloves
Use

Discharge/transfer AST Percent Adherence
= Number of patients with
discharge/transfer AST performed /
Number of patients discharge/transfer AST
eligible x100.

Discharge/Transfer
AST

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Hand Hygiene

Admission AST

MDRO and CDI Module

Surveillance
Method
Active
Surveillance
Testing
Outcome
Measures
(MRSA &
VRE Only)

Forms

Rate

Numerator &
Denominator:
MDRO and CDI
Prevention Process &
Outcome Measures
Monthly Monitoring

Eligible patients =
All
(All patients
regardless of history
of MDRO)

AST Admission
Prevalence rate =
Number of
admission AST or
clinical positive /
Number of
admissions x100

Measures
Eligible patients =
NHx
(No history)

Admission
Prevalence Rates
of MDRO by AST
Eligibility

AST Admission
Prevalence rate =
Number of
admission AST or
clinical positive +
Number of known
positive / Number of
admissions x100.
AST Incidence Rate = Number of
MDRO Healthcare
discharge/transfer AST or clinical positive
Acquisition
cases / Number of patient days x 1,000

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MDRO and CDI Module

Appendix 1. Guidance for Handling MDRO and CDI Module Infection Surveillance and
LabID Event Reporting When Also Following Other NHSN Modules
If a facility is monitoring CLABSIs, CAUTIs, VAPs, or VAEs within the Device-Associated Module and/or
SSIs within the Procedure-Associated Module and is also monitoring MDROs (e.g., MRSA) in the MDRO
and CDI Module, then there are a few situations where reporting the infection or LabID event may be
confusing. The following scenarios provide guidance to keep the counts and rates consistent throughout
your facility and between all of the NHSN Modules. These rules apply to the reporting of “Big 4”
infections (BSI, UTI, PNEU, VAE, and SSI) caused by an MDRO selected for monitoring.
Device-Associated Module with MDRO and CDI Module
Scenario 1: Facility is following CLABSI, CAUTI, VAP, or VAE along with MDRO Infection Surveillance
and possibly LabID Event Reporting in the same location:
Healthcare-associated Infection identified for this location.
1. Report the infection (BSI, UTI, PNEU, or VAE).
2. Answer “Yes” to the MDRO infection question.
This fulfills the infection reporting requirements of both modules in one entry and lets the NHSN reporting
tool know that this infection should be included in both the Device-Associated and the MDRO infection
datasets and rates.
3. If following LabID event reporting in the same location, report also (separately) as a LabID Event (if
meets the MDRO protocol criteria for LabID event).

Scenario 2: Facility is following CLABSI, CAUTI, VAP, or VAE along with MDRO Infection Surveillance
and possibly LabID Event Reporting in multiple locations:
All healthcare-associated infection criteria first fully present together the day of patient transfer from one
location (the transferring location) to another location (the new location), or the next day.
1. Report the infection (BSI, UTI, PNEU and VAE) and attribute to the transferring location, if
transferring location was following that Event Type (BSI, UTI, PNEU, VAE) on the day of Event,
which occurred on the date of transfer, or the following day.
2. Answer “Yes” to the MDRO infection question, if the transferring location was following that
MDRO on the day of Event, which occurred on the date of transfer, or the following day.
3. If, on the date of culture collection, the new location is following LabID event reporting, report also
(separately) as a LabID Event and attribute to the new location (if meets the MDRO protocol criteria
for LabID event).
Procedure-Associated Module with MDRO and CDI Module
Note: SSIs are associated with a procedure and not a patient location, but MDROs are connected with the
patient location.
Scenario 3: Facility is following SSI along with MDRO Infection Surveillance and possibly LabID Event
Reporting:

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MDRO and CDI Module

Patient has surgery, is transferred to a single unit for the remainder of the stay, and during the current stay
acquires an SSI.
1. Report the infection (SSI) and attribute to the post-op location.
2. Answer “Yes” to the MDRO infection question, if the post-op location is following that MDRO
during the month of the date of event.
3. If following LabID event reporting in the post-op location, report also (separately) as a LabID Event
(if meets the MDRO protocol criteria for LabID event).
Scenario 4: Facility is following SSI along with MDRO Infection Surveillance and possibly LabID Event
Reporting:
Patient has surgery, is either discharged immediately (outpatient) or transferred to a unit (inpatient), is
discharged, and subsequently is readmitted with an SSI.
1. Report the infection (SSI) and attribute to the discharging (post-op) location (not the readmission
location).
2. Answer “Yes” to the MDRO infection question, if the discharging (post-op) location was following
that MDRO during the Date of Event*.
3. If following LabID event reporting in the readmitting location or outpatient clinic where the
specimen was collected, report also (separately) as a LabID Event (if meets the MDRO protocol
criteria for LabID event).
* This change corrects the guidance addressing the need to utilize a single event for different surveillance
purposes, i.e., that the entry of one event (SSI) may fulfill reporting requirements in another module
(MDRO Infection Surveillance option) and because of cross-over in calendar months, may result in
conflicting reporting requirements for location.

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MDRO and CDI Module

Appendix 2: Determining Patient Days for Summary Data Collection: Observation vs. Inpatients
In response to questions regarding how to count patient days for “observation” patients, the following
guidance is offered.
The NHSN instructions for recording the number of patients in an inpatient unit state that for each day of
the month selected, at the same time each day, the number of patients on the unit should be recorded. This
procedure should be followed regardless of the patient’s status as an observation patient or an inpatient.
1. Observation patients in observation locations: An “observation” location (e.g., 24-hour observation area)
is considered an outpatient unit, so time spent in this type of unit does not ever contribute to any
inpatient counts (i.e., patient days, device days, admissions). Admissions to such outpatient units
represent “encounters” for the purposes of outpatient surveillance for LabID Event monitoring in the
MDRO/CDI module.
2. Observation patients in inpatient locations:
a. a. If an observation patient is transferred from an observation location and admitted to an
inpatient location, then only patient days beginning with the date of admission to the inpatient
location are to be included in patient day counts (for the location or facility-wide inpatient). In
this same way, device days accrue beginning when the patient arrives in any location where
device-associated surveillance is occurring and in accordance with the location’s device-count
methods.
b. If an observation patient is sent to an inpatient location for monitoring, the patient should be
included for all patient and device day counts. The facility assignment of the patient as an
observation patient or an inpatient has no bearing in this instance for counting purposes, since the
patient is being housed, monitored, and cared for in an inpatient location.
Below is an example of attributing patient days to a patient admitted to an inpatient location, regardless of
whether the facility considers the patient an observation patient or an inpatient.
The examples show counts taken at: A) 12:00 am and B) 11:00 pm.

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MDRO and CDI Module

A. Count at 12:00 am (midnight):
Date
01/01

Mr X Pt Day
Mr X admitted at 8:00 pm

Mr Y Pt Day
Mr Y admitted at 12:00 am

Mr X not counted because the count for
01/01/10 was taken at 12:00 am on 01/01 10
and he was not yet admitted

Mr Y is counted because the count for 01/01
was taken at 12:00 am and that is when he
was admitted

X
1
2
3
Mr X discharged at 5:00 pm
4
Counted for 01/05 because he was in the
hospital at 12:00 am on 01/05 when the
count for that day was taken
4 patient days

1
1
2
3
Mr Y discharged at 12:01 am
5
Counted for 01/05 because he was in the
hospital at 12:00 am on 01/05 when the
count for that day was taken
5 patient days

01/02
01/03
01/04
01/05

Total

If we use the same admission dates and times for Mr X, but a different time is selected for the patient day
count, say 11:00 pm, the total number of days in the count will be the same; they will simply be coming
from different dates.
B. Count at 11:00 pm:
Date
01/01

01/02
01/03
01/04
01/05

Mr X
Mr X admitted at 8:00 am

MR X discharged at 5:00 pm

Total

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Pt Day
1
Counted because the count for 01/01 is taken
at 11:00 pm on 01/01 and he is in the hospital
at that time
2
3
4
X
Not counted for 01/05 because he was not in
the hospital at 11:00 pm on 01/05 when the
count for that day was taken
4 patient days

MDRO and CDI Module

Determining Admission Counts for Summary Data Collection:
In response to questions regarding how to count number of admissions, the following guidance is offered.
We understand that there are a variety of ways in which patient day and admission counts are obtained for a
facility and for specific locations. We offer this guidance to assist with standardization within and across
facilities. It is most important that whatever method is utilized, it should be used each and every month for
consistency of data and metrics. How you operationalize this guidance will depend on how you are
obtaining the data for your counts. If you are calculating admission counts by hand or are utilizing electronic
patient data to do your calculations by hand, then admission counts should be calculated at the same time
each day, as is the method for counting patient days in NHSN. We suggest that calculating patient day and
admission counts concurrently may be the easiest and most efficient method. This will provide consistency
and will eliminate questions about inclusion for individuals who are only present in the facility or in a
specific location for a very brief period of time, since there is no minimum number of hours the patient must
be present before being counted. Any patient who meets criteria for new inclusion should be counted,
regardless of whether they are coded by the facility as an inpatient or as an observation patient. If
admissions are calculated electronically for you, then you must check those data to be sure that all
appropriate patients are included or excluded from those counts and that your electronic data are within +/5% of the number obtained if doing the calculations manually. If these counts are more than 5% discrepant,
then you will need to evaluate and discuss with your IT staff to determine the cause of the discrepancies and
methods to address them. Large numbers of brief admissions and patients placed in inpatient locations under
“observation” status could be contributing to identified discrepancies. The main goal is to accurately count
patients in the denominators that are at risk for potentially contributing to the numerator.
1. Facility-Wide Inpatient Admission Count: Include any new patients that are assigned to a bed in any
inpatient location within the facility at the time of the facility-wide admission count. Qualification as
a new patient means that the patient was not present on the previous calendar day at the time of the
patient day count. The daily admission counts are summed at the end of the calendar month for a
monthly facility-wide inpatient admission count.
2. Inpatient Location-Specific Admission Count: Include any new patients that are assigned to a bed in the
specific inpatient location at the time of the location-specific admission count. Qualification as a new
patient means that the patient was not present on the previous calendar day at the time of the patient day
count. The daily admission counts are summed at the end of the calendar month for a monthly inpatient
location-specific admission count.
Below is an example of manually counting location-specific and facility-wide admission counts related to a
patient admitted to an inpatient location and transferred to multiple patient locations during his hospital stay.
The example shows counts taken at 11:00 pm.

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MDRO and CDI Module

Example: Counts at 11:00 pm:

January 2013

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