Protected Health Information (PHI)

The Health Insurance Portability and Accountability Act (HIPAA), Public Law 104-191, enacted on August 21, 1996, protects the privacy of "protected health information" (PHI) [1]. There are 18 elements of PHI as defined by HIPAA:

  1. Names;

  2. All geographical subdivisions smaller than a State, including street address, city, county, precinct, zip code, and their equivalent geocodes, except for the initial three digits of a zip code, if according to the current publicly available data from the Bureau of the Census: (1) The geographic unit formed by combining all zip codes with the same three initial digits contains more than 20,000 people; and (2) The initial three digits of a zip code for all such geographic units containing 20,000 or fewer people is changed to 000;

  3. All elements of dates (except year) for dates directly related to an individual, including birth date, admission date, discharge date, date of death; and all ages over 89 and all elements of dates (including year) indicative of such age, except that such ages and elements may be aggregated into a single category of age 90 or older;

  4. Phone numbers;

  5. Fax numbers;

  6. Electronic mail addresses;

  7. Social Security numbers;

  8. Medical record numbers;

  9. Health plan beneficiary numbers;

  10. Account numbers;

  11. Certificate/license numbers;

  12. Vehicle identifiers and serial numbers, including license plate numbers;

  13. Device identifiers and serial numbers;

  14. Web Universal Resource Locators (URLs);

  15. Internet Protocol (IP) address numbers;

  16. Biometric identifiers, including finger and voice prints;

  17. Full face photographic images and any comparable images; and

  18. Any other unique identifying number, characteristic, or code, except a code to permit re-identification of the de-identified data by the Honest Broker. (Note: this does not include the unique code assigned by an investigator to code the data.)

There are also additional standards and criteria to protect individuals from re-identification. Any code used to replace the identifiers in data sets cannot be derived from any information related to the individual and the master codes, nor can the method to derive the codes be disclosed. For example, a subject’s initials cannot be used to code their data because the initials are derived from their name. Additionally, the researcher must not have actual knowledge that the research subject could be re-identified from the remaining identifiers in the PHI used in the research study. In other words, the information would still be considered identifiable if there was a way to identify the individual even though all of the 18 identifiers were removed.

Safe Harbor De-Identified Datasets

HIPAA requires that each of the 18 PHI identifiers of the individual or of relatives, employers, or household members of the individual must be removed from medical record information in order for the records to be considered a de-identified “Safe Harbor” dataset.

Expert Determination of De-Identified Datasets

A dataset can also be de-identified by “expert-determination.” The expert must have professional, academic, or other formal training and experience in using health information de-identification methodologies. The expert may determine that the risk of data re-identification is “very small” when the anticipated recipients use it alone or in combination with other reasonably available information.

Limited Datasets

To qualify as a Limited Dataset, HIPAA requires that each of the following identifiers of the individual or of relatives, employers, or household members of the individual must be removed from the data.

  1. Names

  2. Postal address information, other than town or city, State, and zip code

  3. Telephone numbers

  4. FAX numbers

  5. Electronic mail addresses

  6. Social security numbers

  7. Medical record numbers

  8. Health plan beneficiary numbers

  9. Account numbers

  10. Certificate/license numbers

  11. Vehicle identifiers and serial numbers; license plate numbers

  12. Device identifiers and serial numbers

  13. Web Universal Resource Locators (URLs)

  14. Internet Protocol (IP) address numbers

  15. Biometric identifiers

  16. Full face photographic images and any comparable images

References

  1. U.S. Department of Health and Human Services, Health Information Privacy.[Accessed 2024-11-12]; https://www.hhs.gov/hipaa/for-professionals/privacy/laws-regulations/index.html

Resources

Books

  • Institute of Medicine (US) Committee on Health Research and the Privacy of Health Information: The HIPAA Privacy Rule; Nass SJ, Levit LA, Gostin LO, editors. Beyond the HIPAA Privacy Rule: Enhancing Privacy, Improving Health Through Research. Washington (DC): National Academies Press (US); 2009. Available from: https://www.ncbi.nlm.nih.gov/books/NBK9578/ doi: 10.17226/12458

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