What is considered a "limited data set" under HIPAA?

A "limited data set" under HIPAA is specifically defined as a subset of data that excludes certain direct identifiers of the individual or their relatives, household members, or employers, while still retaining other potentially identifiable information. This designation allows for the use of certain health information for purposes such as research, public health, and other healthcare operations, while still aiming to protect patient privacy.

In this context, the correct answer highlights that while the data retains some variants that can be linked to the individual, it effectively balances the need for data analysis and usage with the requirements of privacy and confidentiality. Characteristics like this make the limited data set a useful tool, particularly since it allows the exchange of necessary information without compromising patient identity completely.

The other options do not fulfill the criteria for a limited data set under HIPAA. Identifying data is on the contrary not permissible within a limited data set, while fully anonymized data does not meet the criteria because such data has had all identifiers removed, thus likely exceeding the scope of a limited data set definition. Lastly, data solely used for marketing purposes does not fall under the definition of a limited data set as it pertains to uses outside of treatment, payment, or healthcare operations crucial in the HIPAA framework.