An Easy-to-use and Robust Approach for the Differentially Private De-Identification of Clinical Textual Documents

TL;DR

This paper presents a robust, differentially private method for de-identifying clinical textual documents, specifically in French, ensuring privacy while maintaining document integrity, and adaptable to other languages.

Contribution

It introduces a novel approach that combines strengthened de-identification techniques with state-of-the-art differential privacy mechanisms, validated with mathematical robustness.

Findings

Effective de-identification of French clinical documents

Mathematically proven robustness of the approach

Potential for adaptation to other languages

Abstract

Unstructured textual data is at the heart of healthcare systems. For obvious privacy reasons, these documents are not accessible to researchers as long as they contain personally identifiable information. One way to share this data while respecting the legislative framework (notably GDPR or HIPAA) is, within the medical structures, to de-identify it, i.e. to detect the personal information of a person through a Named Entity Recognition (NER) system and then replacing it to make it very difficult to associate the document with the person. The challenge is having reliable NER and substitution tools without compromising confidentiality and consistency in the document. Most of the conducted research focuses on English medical documents with coarse substitutions by not benefiting from advances in privacy. This paper shows how an efficient and differentially private de-identification approach can be achieved by strengthening the less robust de-identification method and by adapting state-of-the-art differentially private mechanisms for substitution purposes. The result is an approach for de-identifying clinical documents in French language, but also generalizable to other languages and whose robustness is mathematically proven.