Kulldorrf M, Nagarwalla N
Spacial disease clusters: Detection and inference
Statistics in Medicine
We present a new method for detection and inference for spatial clusters of a disease. To avoid ad hoc procedures to test for clustering, we have a clearly defined alternative hypothesis and our test statistic is based on the likelihood ratio. The proposed test can detect clusters of any size, located anywhere in the study region. It is not restricted to clusters that conform to pre-defined administrative or political borders. The test can be sued for spatially aggregated data as well as when exact geographic co-ordinates are known for each individual. We illustrate the method on a data set describing the occurrence of leukemia in Upstate New York.