Differential privacy in health research: A scoping review

Abstract

Objective: Differential privacy is a relatively new method for data privacy that has seen growing use due its strong protections that rely on added noise. This study assesses the extent of its awareness, development, and usage in health research.

Materials and methods: A scoping review was conducted by searching for ["differential privacy" AND "health"] in major health science databases, with additional articles obtained via expert consultation. Relevant articles were classified according to subject area and focus.

Results: A total of 54 articles met the inclusion criteria. Nine articles provided descriptive overviews, 31 focused on algorithm development, 9 presented novel data sharing systems, and 8 discussed appraisals of the privacy-utility tradeoff. The most common areas of health research where differential privacy has been discussed are genomics, neuroimaging studies, and health surveillance with personal devices. Algorithms were most commonly developed for the purposes of data release and predictive modeling. Studies on privacy-utility appraisals have considered economic cost-benefit analysis, low-utility situations, personal attitudes toward sharing health data, and mathematical interpretations of privacy risk.

Discussion: Differential privacy remains at an early stage of development for applications in health research, and accounts of real-world implementations are scant. There are few algorithms for explanatory modeling and statistical inference, particularly with correlated data. Furthermore, diminished accuracy in small datasets is problematic. Some encouraging work has been done on decision making with regard to epsilon. The dissemination of future case studies can inform successful appraisals of privacy and utility.

Conclusions: More development, case studies, and evaluations are needed before differential privacy can see widespread use in health research.

Keywords: confidentiality; data sharing; differential privacy; privacy; statistical disclosure limitation.

Figure 1.

Yearly count of publications on differential privacy found on EBSCOhost. Obtained from a keyword-only search of “differential privacy” (full-text search results excluded). For comparison, a similar search of “k-anonymity,” another popular statistical disclosure limitation method, yields 49 publications in the year 2006, with an increase to 349 publications in the year 2020. A keyword search of “de-identification” yields 116 publications in the year 2006, with an increase to 490 publications in the year 2020.

Figure 2.

Flow diagram of study selection.