DISEASE-MODELS IMPLICIT IN STATISTICAL TESTS OF DISEASE CLUSTERING

State and local health departments investigate an increasing number of cluster allegations, for which the selection of ap propriate statisti cal methods is an important problem. Many of the methods for the spati al analysis of health data assume, either implicitly or explicitly, so me model of disease occurrence, and comparisons of methods can be diff icult when their underlying disease models differ. We review some of t he issues involved in the statistical analysis of spatial disease patt erns and describe several methods recently proposed to detect areas of increased disease rates. The disease models upon which the methods ar e based are explicitly described, and they provide a useful basis for comparing alternative clustering methods.