Distance and Risk Measures for the Analysis of Spatial Data: A
Study of Childhood Cancers This work compares distance and risk
measures as ways to detect spatial clusters of disease
associated with a point source exposure. Also included is an
application of these two approaches to childhood cancer data for
the city of San Francisco (1973-88). The distributions of
incident cases of leukemia (51 cases), brain cancer (35 cases)
and lymphatic cancer (35 cases) among individuals less than 21
years of age are described using three statistical measures:
distance on a geopolitical map, distance on a density equalized
transformed map, and relative risk. The point source of exposure
investigated is a large microwave tower located southwest of the
center of the city (Sutro Tower). These three statistical
methods are contrasted to explore the advantages and
disadvantages of using distance and risk measures in the
analysis of spatial data. All three measures of spatial
clustering are shown to perform similarly when a spec