Health Data in an Open World

Understand

With the aim of informing sound policy about data sharing and privacy, we describe successful re-identification of patients in an Australian de-identified open health dataset.

• As in prior studies of similar datasets, a few mundane facts often suffice to isolate an individual.
• Some people can be identified by name based on publicly available information.
• Decreasing the precision of the unit-record level data, or perturbing it statistically, makes re-identification gradually harder at a substantial cost to utility.