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These can be confusing adjectives when referring to study data. Included below is a mini-glossary to help you with your IRB applications. 

  • Coded
    Data are coded when a link will exist between a unique code and individual subjects’ identifiers such as name, medical record number, email address or telephone number. Generally, the data is collected with a “Study ID,” and a linkage file is maintained where the Study ID is associated with the subject’s identifiers. 

    The code should not be a combination of information related to the individual, such as initials, date of birth, etc. It can be sequential numbers and/or letters, such as ST01, ST02, ST03, and so on.

  • De-identified
    Data are considered de-identified when any direct or indirect identifiers or codes linking the data to the individual subject’s identify are destroyed or there is no potential for deductive disclosure. De-identification can occur by removing the code from the dataset or destroying the linkage file. At this point, no data can be linked back to an individual. A list of the 18 direct identifiers is in the IRBIS application section A.9 for reference.    

    For example: A dataset received from another researcher may contain a code, but it may be considered de-identified provided the original researcher does not use the link to re-identify the individual or disclose the link to the receiving researcher. 

    As a reminder for secondary use of data: if an investigator was involved with the original data collection, even if all identifiers have been removed, this is still considered human subject research and does not meet the definition of not human subject research (NHSR).

  • Anonymous
    The DHHS-Office for Human Research Protections (OHRP) describe coded and de-identified and do not define anonymous in the regulations. 

    Data are anonymous if no one, not even the researcher or a third party entity (e.g., Qualtrics), can connect the data to the individual who provided it through direct identifiers such as name, address, IP address or any type of identification number or indirect identifiers (i.e., other unique individual characteristics like age, race, socioeconomic level, etc.) that might make it possible to identify an individual from a pool of subjects.  

    If a survey includes a demographics section or is being collected through a third party vendor, the researcher cannot guarantee anonymity and should not be included in recruitment or consent materials.

If you have questions about the IRB or need any assistance with your submission, email the IRB at 

To submit a topic or question for a future DYK, email Celeste Cantrell 

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