NHSN External Validation Frequently Asked Questions

FAQ’s: NHSN External Validation

If you have questions that are not answered below, please email nhsn@cdc.gov with the subject line “External Validation Toolkit” for additional support.

Q1. Is there a recommended time of year to complete external validation of facility level data?

Validation can occur at any time of the year. The decision of when to conduct validation within your jurisdiction should consider the period of time the data you plan to freeze and include in your facility selection. Please review the facility section method within the toolkit to determine if you jurisdiction would likely be able to collect the minimum required data at the time of year you are interested in validating.

When planning your validation with facilities please consider that facilities participating in the CMS Hospital Inpatient Quality Reporting (IQR) Program have reporting deadlines from the previous calendar year that occur up until May 15th of the current year.

This may impact what data you can collect from a facility at the beginning of each year. For example, facilities participating in the IQR have until 5/15/2023 to submit any required data that was collected between 10/1/2022-12/31/2022.


Q2. How long do we have to complete the External Validation Toolkit (EVT)?

There is not a defined deadline to complete validation work. We request that you complete at least one cycle of validation during each calendar year.

The term “cycle” refers to the validation of one HAI and its data reported to NHSN over a calendar year period using one of the methods outlined in the EVT.

We recommend a minimum of 6 months of data be used in a cycle and encourage a full year if feasible to increase the likelihood of identifying event records.


Q3. How do we determine what healthcare affiliated infections (HAI) to validate?

The current version of the EVT has guidance to complete validation of six (6) HAI’s (CLABSI, CAUTI, SSI-COLO, SSI-HYST, LabID-CDI, MRSA) within acute care settings.

Jurisdictions can select to perform validation on any of these options.

Please contact the Measure Development and Validation Unit at nhsn@cdc.gov, using subject line “External Validation Toolkit”, to inform us that you are interested in in using the EVT.


Q4. Are we required to use a specific method outlined in the External Validation Toolkit?

The choice of what methodology from the toolkit to use is at the discretion of the jurisdiction conducting the validation. However, we do encourage the use method 3 if possible. This method prioritizes selecting facilities randomly to create representative samples.


Q5. Do we have to use REDCap for data collection/Can we use our own in-house developed REDCaps instead?

We highly recommend the use of the REDCap MRATs we provide to keep data as standardized as possible. If your jurisdiction decides to not use the instruments we have provided, we may not be able
to include your jurisdiction’s data in our aggregated. Please contact us if you plan on using your own instruments before you begin your validation.


Q6. Where do we send our abstracted data after we’ve completed our validation?

Please see the guidance document for exporting and sending REDCap data.


Q7. Can we use the External Validation Toolkit in Dialysis and Long-Term Care facilities?

The current version of the EVT is to be used exclusively for Acute Care Facility settings. We are currently updating the toolkit to include dialysis and long-term care protocols and definitions. Additional resources will be posted on the Validation webpage as soon as these documents are ready. We will make an announcement when these materials are ready.