Spatial focus test
	Focused tests hypothesize that risk decreases as distance increases
from the focus.
Notes:
-  By "a priori knowledge" we mean knowledge of spatial range of
effect and spatial decay of physical processes mediating exposure,
information which is captured in the Relative Risk Function.
-  N.B.: Do not use the observed spatial disease pattern to estimate the
Relative Risk Function! To do so is a tautology and invalidates statistical
inference.
Website maintained by Andy Long.
Comments appreciated.
longa@nku.edu