Welcome to the NHSN Quick Learn, Denominator Device Day and Central Line Day Counts for
Device Attribution.
This video was created to clarify a change in the 2018 Laboratory Confirmed Bloodstream
Infection, or LCBI chapter regarding denominator device day and central line day counts for
device attribution.
By the end of this instruction, the viewer will be able to:
Define denominator device day, perform denominator device day counts, define central line day
counts for device attribution and perform central line day counts for device attribution.
What is a denominator device day?
A denominator device day is the count of central lines on an inpatient unit that will be recorded
in the monthly denominator summary data.
Depending on your facility, you may perform denominator device day counts – Manually
or Electronically.
Remember, denominator device days are simply your denominator counts.
So, which central lines are included in the denominator device day counts?
Previously in 2017, non-accessed central lines were not included in denominator device day counts.
However in 2018, all central lines that are present on an inpatient unit
are counted regardless of access.
These central lines include, but are not limited to peripherally-inserted central catheters
or PICC’s, Ports, and hemodialysis catheters.
So, what are central line day counts for device attribution?
Central line day counts for device attribution are the days that contribute to a determination
that a bloodstream infection is a central-line associated BSI or CLABSI.
Specifically, central line day counts for device attribution is every day that the line
is present in an inpatient unit, once it has been accessed in an inpatient unit, until
the line is removed or the patient is discharged.
For central lines inserted during the current admission, central line day count one for
device attribution equals the date of the line placement.
For central lines that are present on admission, central line day count one for device attribution
equals the date of the first access on an inpatient unit.
For NHSN surveillance purposes, access is defined as the following activities-infusion,
blood draws, use for hemodynamic monitoring and of course line placement.
Remember, central line day counts for device attribution are your counts for determining
if a bloodstream infection is a CLABSI.
Let’s look at a table that combines the concepts of denominator device days and central
line day counts for device attribution.
Patient A was admitted to an intensive care unit or an ICU on August 5th and a central
line was placed on the same day.
This table is pretty straight forward in that the device days for denominator counts and
the central line day counts for device attribution start on the same day.
This table speaks to a patient admitted with a hemodialysis central line in place.
Patient B is admitted to the emergency department or ED on December 31st.
He is transferred to a medical intensive care unit or MICU on January 1st.
So, his device days for denominator counts start on January 1st
which is denominator device day one.
Because his central line was not accessed until January 3rd.
January 3rd is central line day count one for device attribution.
The patient would have a central line that is eligible for a CLABSI event on January
5th or central line day count three for device attribution.
Where can I find guidance on denominator device day counts?
On the surveillance for Bloodstream Infection NHSN website, you will find
the ‘Data Collection Forms’ tab.
Once you click on this tab, you will find an expanded list that includes the Table of
Instructions for Denominators for neonatal intensive care units or NICU’s, specialty
care areas or SCA’s and intensive care units or ICU’s.
And this information can be found on the link below.
Please note that denominator device day counts will be recorded in the NHSN application.
However, central line day counts for device attribution will not be recorded in the NHSN application.
Now, we are going to cover denominator device day count guidance by location.
Let’s start with the neonatal intensive care unit or NICU.
The denominator device day count includes all patients with one or more central lines
at the time of the count regardless of access.
Please note that umbilical catheters are considered central lines.
Here’s how to perform denominator device day counts in NICU’s.
For each day of the month at the same time each day, record the number of patients in
each birthweight category with one or more central lines.
The birthweight categories are listed below ranging from less than or equal to 750 grams
to greater than 2500 grams.
This is the NICU Denominator Form.
The denominator device day counts for central lines are recorded in the column denoted CL
for each birthweight category.
When entering the data on the NICU Denominator form, total the daily counts.
At the end of each month, record the sums by birthweight.
When entering summary data in the NHSN application, enter denominator device day
counts in the NHSN application under the option to ‘Add Summary Data’ denoted in
the left screenshot slide.
Finally, enter the data in the NICU Summary Data page seen in the screenshot on the right.
Here is a larger screenshot of the summary data page seen on the previous slide.
Please enter your monthly denominator device day data in the column highlighted by the
red box.
It is important to note that the column, Central Line Days, is referring to denominator device
days and not central line day counts for device attribution.
Let’s move on to Specialty Care Areas or SCA’s.
So, what’s included in denominator device day counts?
The denominator device day count includes all patients with one or more central lines
at the time of the count regardless of access.
When performing denominator device day counts in SCA’s, the counts are separated by the
type of central line.
For each day of the month, at the same time every day: record the number of patients with
at least one permanent central line.
Additionally, record the number of patients with at least one temporary central line.
However, if a patient has both a permanent and temporary central line, record the temporary
central line only.
Here is the SCA Denominator Form.
The denominator device day counts are recorded in the columns noted Temporary and Permanent.
When entering data on the SCA Denominator form, total the daily counts.
At the end of the month, record sums by central line type.
When entering summary data in the NHSN application, enter denominator device day counts in the
NHSN application under the option to Add Summary Data denoted in the left screenshot slide.
Finally, enter the data in the SCA Summary Data page seen in the screenshot on the right.
Here is a larger screenshot of an SCA Summary Data page in the NHSN application.
Please enter your monthly denominator device day data in the fields noted for Temporary
Central Line Days and Permanent Central Line Days.
It is important to note that the fields, Permanent Central Line Days and Temporary Central Line
Days, are referring to denominator device days and not central line day counts for
device attribution.
Our final location is the intensive care unit or ICU.
So, what’s included in denominator device day counts?
The denominator device day count includes all patients with one or more central lines
at the time of the count regardless of access.
For each day of the month, at the same time every day: record the number of patients with
at least one central line.
This is the Intensive Care Unit Denominator form.
Denominator device day counts for central lines are recorded in the column highlighted
for the Number of Patients with one or more central lines.
When entering summary data on the ICU Denominator Form, total the daily counts.
At the end of the month, record the sum.
Next when entering summary data in the NHSN application, enter denominator device day
counts in the NHSN application under the option to Add Summary Data
denoted in the left screenshot slide.
Finally, enter in the data in the ICU Summary Data page seen in the screenshot on the right.
Here is a larger screenshot of an ICU Summary Data page in the NHSN application.
Denominator device day counts for central lines are recorded in the field,
Central Line Days.
It is important to note that the field, Central Line days, is referring to denominator device
days and not central line day counts for device attribution.
Central line day counts for device attribution guidance can be found on page four dash sixteen
of the LCBI protocol in Table Three.
Let’s go over a few of those scenarios.
Patient A had a central line placed on April 2nd.
The central line becomes eligible for a CLABSI event on April 4th because on that date, a
central line had been in place greater than two consecutive calendar days.
The central line day count for device attribution will continue until the central line is removed
or the patient is discharged, whichever comes first.
Patient B, also had a central line inserted on April 2nd.
The central line becomes eligible for a CLABSI event on April 4th.
However because the central line is removed on April 4th, the central line day count for
device attribution ends on April 4th.
Please note that the patient remains eligible for a CLABSI until April 5th, the day after
device removal.
This allows for incubation time for a BSI.
Let’s look at Patient C.
This patient had three central line days for device attribution counted by March 31st.
So, the central line became eligible for a CLABSI event on March 31st which is central
line day count three for device attribution.
Notice on April 2nd or central line day count five for device attribution, the central line
is removed, but replaced the following day.
Because a full calendar day did not pass without a central line in place, the central line
day count for device attribution continues uninterrupted.
So let’s look at Patient D.
This patient also had three central line days for device attribution counted by March 31st.
Please note that the central line was removed on April 2nd and replaced on April 4th.
Because a full calendar day passed on April 3rd with no central line in place, the central
line day count for device attribution starts over on April 4th, , which becomes central
line day count one for device attribution.
The patient will not be eligible for a CLABSI event again until April 6th, the new central
line day count three for device attribution.
In conclusion, denominator device day refers to your denominator counts.
It is used to identify the number of central line days that will be attributed to a location
for the month.
Central line day counts for device attribution are used for CLABSI determination.
Denominator device day counts may be performed differently depending on location.
In NICU's, denominator device day counts are performed by birthweight categories.
SCA locations collect denominator device days by the central line type.
In ICU locations, all central lines are included in a single count.
Guidance for denominator device day counts can be found in the Table of Instructions
for Denominators for NICU’s, SCA’s and ICU’s.
Additionally, guidance for central line day counts for device attribution can be found
in Table Three of the LCBI protocol page 4-16.
This concludes the NHSN Denominator Device Day and Central Line Day Counts for Device Attribution.
If you have questions regarding the content of this presentation, please contact nhsn@cdc.gov.