Data Validation & Testing

Why is data validation important to facilities reporting data?

Data validation is important to facilities participating in NHSN for several reasons. First, per the NHSN Agreement to Participate and Consent submitted by each facility during enrollment, to be eligible to participate in NHSN, facilities must “be willing to follow the selected NHSN component protocols exactly and report complete and accurate data in a timely manner when reporting data for use by CDC.” Failure to comply with this and the other requirements stipulated in the Agreement to Participate and Consent will result in withdrawal from NHSN.

In the future, it is expected that external organizations, such as CMS and possibly state health departments, will pursue data validation activities, which may have payment and/or regulatory implications. Early data validation by facilities will provide more time to identify and make corrections to problems with NHSN data collection and reporting processes.

Most importantly, the purpose of reporting complete and accurate surveillance data is to generate information that is useful for monitoring facility performance and driving prevention activities. Unreliable data are not useful to quality improvement efforts.


What is the role of the sender for validating CDA data?

CDC expects that the sender has done adequate data validation to ensure data being reported using CDA are complete and correct by comparing data collected manually to data obtained from CDA (both numerator and denominator). In addition, a facility-based NHSN user is expected to have access to NHSN and continue to review the data in NHSN on an ongoing basis to verify data reported via CDA are complete and correct.

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How should CDA data be validated and who should be involved in validation efforts?

Both the CDA implementer and the sender are expected to be involved in validation of CDA files. During the development of CDA, the CDA implementer must use the CDA Implementation Guide (IG), The Lantana Group’s Schematron Validator and NHSN test facilities to verify CDA files are created to the correct NHSN specifications. Following development of CDA capacity, if possible, a person within the facility is expected to compare manually collected data with CDA data to verify that they are the same, and then continue to review the data in NHSN on an ongoing basis to verify data continue to be reported completely and correctly.


Validation has identified errors in data that have already been reported to NHSN; what do we do?

If incorrect data have been reported to NHSN, either manually add, edit and delete records in NHSN to make corrections or import a corrected CDA file using the succession management process (refer to the Implementation Guide and contact the NHSN CDA Helpdesk at for more information). Corrections should be made as soon as possible after discovery. Contact your CDA implementer if the data were submitted using CDA to ensure the problem is not repeated in future CDA files.


Guidance for Validation Tools and Test Sites

Visit the Validation Tools & Test Sites page.