  Hospitals and health care organizations collect large amounts of detailed
health care data that is in high demand by researchers. Thus, the possessors of
such data are in need of methods that allow for this data to be released
without compromising the confidentiality of the individuals to whom it
pertains. As the geographic aspect of this data is becoming increasingly
relevant for research being conducted, it is important for an
\emph{anonymization} process to pay due attention to the geographic attributes
of such data. In this paper, a novel system for health care data anonymization
is presented. At the core of the system is the aggregation of an initial
regionalization guided by the use of a Voronoi diagram. We conduct a comparison
with another geographic-based system of anonymization, GeoLeader. We show that
our system is capable of producing results of a comparable quality with a much
faster running time.
