May 20, 2021


The staff of the Committee on Open Government is authorized to issue advisory opinions. The ensuing staff advisory opinion is based solely upon the information presented in your correspondence, except as otherwise indicated.


I am writing in response to your request for an advisory opinion regarding the manner in which the New York State Department of Health (the “Department”) responded to your Freedom of Information Law (“FOIL”) request for records reflecting coronavirus hospital admissions and coronavirus hospital deaths.

In response to your request, the FOIL Appeals Officer in its Determination dated April 28, 2021, advised:

The RAO answered your request correctly: the RAO properly provided you with the responsive portions of DOH documents that are responsive to your request, but with redactions made-lawfully under POL § 87(2)(b). FOIL exempts from disclosure records and portions of records that, if disclosed, would constitute an “unwarranted invasion of personal privacy.” POL§ 87(2)(b). Here, the redactions under POL § 87(2)(b) were appropriate because these redactions safeguarded the privacy of references to cohorts or cells that had a size of six or fewer individuals, which is information that could be used to invade the personal privacy of individuals.

In your request for an advisory opinion, you challenge the Department’s determination to withhold hospital admissions and deaths data reflecting cohorts or cells that have a size of six or few individuals, stating:

There is no possible way that it protects privacy to refuse to say whether 5 unidentified patients were admitted to Mercy Hospital, or 6 unidentified patients were admitted to Mercy Hospital. No names are being disclosed. Nobody is asking for names. It just doesn't make sense.

Upon receipt of your inquiry, I contacted the Department and afforded it the opportunity to provide any additional information it believed would assist staff of the Committee in forming an opinion as to the appropriateness of the redactions. The Department’s response to my inquiry is attached for your reference.

As you are likely aware, FOIL is based upon a presumption of access. All records of an agency are available, except to the extent that records or portions thereof fall within one or more grounds for denial appearing in § 87(2)(a) through (q) of the Law. Section 87(2)(b) of FOIL authorizes an agency to withhold records or portions of records which if disclosed would constitute an unwarranted invasion of personal privacy. Here, the records you seek do not contain names of patients but rather information confirming other information (i.e., admissions and deaths) about, of relevance here, small groups of patients. Notwithstanding this distinction, the Department determined that disclosure of admissions or deaths data without naming patients, where the number of admissions or deaths is six or fewer, in conjunction with other publicly-available information, could reasonably lead to the identification or re-identification of the patients in the cohort or cell.

As noted in the Department’s response to my inquiry, this position on non-disclosure of de-identified small group data is supported not only by New York State decisional law (see Hassig v. New York State Department of Health, 742 N.Y.S.2d 442, 444 (3d Dep’t 2002); Suhr v. New York State Department of Civil Service, 142 N.Y.S.3d 616, 620-21 (3d Dep’t 2021)), but also by long-standing State and Federal guidelines requiring “cell suppression” for the health data of smaller groups of individuals. The attached letter from the Department includes the referenced policies, including those from the United States Centers for Medicare and Medicaid Services, Centers for Disease Control and Prevention, and Department of Health and Human Services. The Department in its letter also made reference to its obligations to protect the confidentiality of patient data under the federal Health Insurance Portability and Accountability Act and the New York State Personal Privacy Protection Law (the “PPPL”).

Based on a review of decisional law and the federal guidance, an agency’s decision to withhold de- identified data of small cells or cohorts that could be used in conjunction with other publicly-available information to identify individuals is, in our view, consistent with FOIL and the PPPL. Staff of the Committee have previously prepared advisory opinions relating to this issue when the data in question relates to protected health information or personally identifiable information in the education setting. See FOIL AO 16124, FOIL AO 19458, FOIL AO 19648, FOIL AO 19741.

Given the Department’s longstanding reliance on established federal guidelines for withholding information from small cells or cohorts of patient data to prevent inadvertent disclosure of information which, when combined with public information, could identify patients in violation of state and federal law, it is our opinion that its determination in this instance was consistent with its obligations under FOIL and the PPPL.

I hope this information proves useful.


/s/ Kristin O’Neill

Kristin O’Neill
Assistant Director


cc:   David J. Spellman, FOIL Appeals Officer