De-Identifying Protected Health Information: OCR Issues Long-Awaited Guidance

by Pepper Hamilton LLP

The HIPAA Privacy Rule is intended to protect individually identifiable health information by limiting its use and disclosure. But the Privacy Rule expressly permits the de-identification of that information, and in doing so recognizes the usefulness of that information for “secondary purposes” such as comparative effectiveness studies, policy assessment and life sciences research. The Privacy Rule prescribes two methods by which individually identifiable information can be de-identified; one method requires the involvement of an expert, and the other does not.

Almost three years following the workshop convened by the U.S. Department of Health and Human Services Office of Civil Rights (OCR) to develop guidelines for implementing the two methods, OCR has published its Guidance Regarding Methods for De-Identification of Protected Health Information (the Guidance), which clarifies the two methods.

Expert Determination

Under the Privacy Rule, a covered entity may conclude that health information is not individually identifiable if “a person with appropriate knowledge of and experience with generally accepted statistical and scientific principles and methods ... (i) applying such principles and methods, determines that the risk is very small that the information could be used ... to identify an individual who is a subject of the information ... and (ii) documents the methods and results of the analysis that justify such determination.” 45 CFR §164.514(b)(1).

The Guidance clarifies that the “expert” need possess no particular professional degree or certification in order to de-identify health information. It also notes that while the Privacy Rule does not require that determinations of de-identification be time-limited, changes in technology, social conditions and the availability of information over time have led de-identification practitioners in fact to impose time limits on their determinations. The result is that a covered entity may need to consult its expert upon expiration of the determination period, to assess whether the data requires additional or different de-identification efforts to remain sufficiently de-identified.

Interestingly, the Guidance does not attempt to quantify the level of risk that qualifies as “very small,” noting that the risk of identification for one data set in one context may not be the same as the risk of identification for the same data set in another context. Similarly, the Guidance acknowledges that there may be multiple “solutions” for de-identifying a particular data set. Some commenters think these guidelines should be more specific.

The great bulk of the Guidance regarding Expert Determination is devoted to a detailed and instructive discussion of the principles used by experts in determining the identifiability of health information (see the Guidance’s useful Table 1); the degree to which a data set containing health information about individuals can be linked to a data set that discloses the identity of the same individuals (see the Guidance’s Figure 3); and the approaches used by experts to de-identify individual health information, such as suppression, generalization and perturbation of patient values.

Safe Harbor

Under the Privacy Rule, a covered entity may also conclude that health information is not individually identifiable if (i) 18 specific identifiers (name, telephone number, social security number, etc.) of the individual and certain others are redacted and (ii) “the covered entity does not have actual knowledge that the information could be used ... to identify an individual who is a subject of the information.” 45 CFR §164.514(b)(2).

The Guidance clarifies when zip codes can be used in de-identified information and explains when dates are and are not permitted to be included. It also gives examples of the eighteenth identifier: “any other unique identifying number, characteristic or code.”

The Guidance addresses “actual knowledge,” offering examples of knowledge on the part of a covered entity that would constitute actual knowledge (where, for example, a patient is the former president of a state university.) Importantly, it points out that medical records exist in both structured and unstructured or “free text” form and that protected health information may well appear in free-text documents or fields. The Guidance provides that whether or not information in free-text documents or fields must be redacted in order to de-identify a particular record will depend on whether or not the information in question gives the covered entity actual knowledge of the identity of the individual.

Finally, the Guidance clarifies that, whether the Expert Determination or the Safe Harbor method is used to de-identify its health information, the covered entity need not require that the recipient of de-identified health information enter into a data use agreement, thus distinguishing the sharing of de-identified information from the sharing of a “limited data set” under the Privacy Rule.

Bottom Line

If compliant with the Guidance, de-identification of patient health data allows organizations that do not need to link the medical information to one unique patient to do valuable analyses and research outside the regulatory purview of the HIPAA Privacy Rule. While the OCR Guidance allows such de-identification of medical data, both de-identification methods approved by OCR, “even when properly applied, yield de-identified data that retains some risk of identification ... [and that] although the risk is very small, it is not zero.” For this reason, organizations embarking on the de-identification of patient health information will need to pay special attention to OCR’s Guidance.

DISCLAIMER: Because of the generality of this update, the information provided herein may not be applicable in all situations and should not be acted upon without specific legal advice based on particular situations.

© Pepper Hamilton LLP | Attorney Advertising

Written by:

Pepper Hamilton LLP

Pepper Hamilton LLP on:

Readers' Choice 2017
Reporters on Deadline

"My best business intelligence, in one easy email…"

Your first step to building a free, personalized, morning email brief covering pertinent authors and topics on JD Supra:
Sign up using*

Already signed up? Log in here

*By using the service, you signify your acceptance of JD Supra's Privacy Policy.
Custom Email Digest
Privacy Policy (Updated: October 8, 2015):

JD Supra provides users with access to its legal industry publishing services (the "Service") through its website (the "Website") as well as through other sources. Our policies with regard to data collection and use of personal information of users of the Service, regardless of the manner in which users access the Service, and visitors to the Website are set forth in this statement ("Policy"). By using the Service, you signify your acceptance of this Policy.

Information Collection and Use by JD Supra

JD Supra collects users' names, companies, titles, e-mail address and industry. JD Supra also tracks the pages that users visit, logs IP addresses and aggregates non-personally identifiable user data and browser type. This data is gathered using cookies and other technologies.

The information and data collected is used to authenticate users and to send notifications relating to the Service, including email alerts to which users have subscribed; to manage the Service and Website, to improve the Service and to customize the user's experience. This information is also provided to the authors of the content to give them insight into their readership and help them to improve their content, so that it is most useful for our users.

JD Supra does not sell, rent or otherwise provide your details to third parties, other than to the authors of the content on JD Supra.

If you prefer not to enable cookies, you may change your browser settings to disable cookies; however, please note that rejecting cookies while visiting the Website may result in certain parts of the Website not operating correctly or as efficiently as if cookies were allowed.

Email Choice/Opt-out

Users who opt in to receive emails may choose to no longer receive e-mail updates and newsletters by selecting the "opt-out of future email" option in the email they receive from JD Supra or in their JD Supra account management screen.


JD Supra takes reasonable precautions to insure that user information is kept private. We restrict access to user information to those individuals who reasonably need access to perform their job functions, such as our third party email service, customer service personnel and technical staff. However, please note that no method of transmitting or storing data is completely secure and we cannot guarantee the security of user information. Unauthorized entry or use, hardware or software failure, and other factors may compromise the security of user information at any time.

If you have reason to believe that your interaction with us is no longer secure, you must immediately notify us of the problem by contacting us at In the unlikely event that we believe that the security of your user information in our possession or control may have been compromised, we may seek to notify you of that development and, if so, will endeavor to do so as promptly as practicable under the circumstances.

Sharing and Disclosure of Information JD Supra Collects

Except as otherwise described in this privacy statement, JD Supra will not disclose personal information to any third party unless we believe that disclosure is necessary to: (1) comply with applicable laws; (2) respond to governmental inquiries or requests; (3) comply with valid legal process; (4) protect the rights, privacy, safety or property of JD Supra, users of the Service, Website visitors or the public; (5) permit us to pursue available remedies or limit the damages that we may sustain; and (6) enforce our Terms & Conditions of Use.

In the event there is a change in the corporate structure of JD Supra such as, but not limited to, merger, consolidation, sale, liquidation or transfer of substantial assets, JD Supra may, in its sole discretion, transfer, sell or assign information collected on and through the Service to one or more affiliated or unaffiliated third parties.

Links to Other Websites

This Website and the Service may contain links to other websites. The operator of such other websites may collect information about you, including through cookies or other technologies. If you are using the Service through the Website and link to another site, you will leave the Website and this Policy will not apply to your use of and activity on those other sites. We encourage you to read the legal notices posted on those sites, including their privacy policies. We shall have no responsibility or liability for your visitation to, and the data collection and use practices of, such other sites. This Policy applies solely to the information collected in connection with your use of this Website and does not apply to any practices conducted offline or in connection with any other websites.

Changes in Our Privacy Policy

We reserve the right to change this Policy at any time. Please refer to the date at the top of this page to determine when this Policy was last revised. Any changes to our privacy policy will become effective upon posting of the revised policy on the Website. By continuing to use the Service or Website following such changes, you will be deemed to have agreed to such changes. If you do not agree with the terms of this Policy, as it may be amended from time to time, in whole or part, please do not continue using the Service or the Website.

Contacting JD Supra

If you have any questions about this privacy statement, the practices of this site, your dealings with this Web site, or if you would like to change any of the information you have provided to us, please contact us at:

- hide
*With LinkedIn, you don't need to create a separate login to manage your free JD Supra account, and we can make suggestions based on your needs and interests. We will not post anything on LinkedIn in your name. Or, sign up using your email address.