Which direct identifier must be removed from research subjects' records to comply with a limited data set?

To comply with the regulations governing a limited data set, specific direct identifiers must be removed from research subjects' records. A limited data set is a type of data release under the Health Insurance Portability and Accountability Act (HIPAA) that allows for the use of identifiable health information without individual identifiers, but with certain restrictions.

In this context, the account number is considered a direct identifier that must be removed to create a limited data set. Account numbers can easily link back to the individual, thus compromising privacy and violating HIPAA compliance if left intact. By removing the account number, the data can be utilized for research while still protecting the privacy of individuals involved.

Other identifiers like social security numbers, phone numbers, and email addresses, while also critical for personal identification, are typically considered separate from the components that constitute a limited data set. The primary focus on compliance is to ensure that the data does not allow for the identification of individuals, and by removing account numbers, compliance with the limited data set requirements is upheld.