Diggle's method is a spatial, focused cluster detection method appropriate for individual-level data. It was developed in two papers, Diggle (1990) and then Diggle and Rowlingson (1994).
The method evaluates the spatial distribution of individuals with the disease of interest (cases). The spatial pattern of case locations is compared with the spatial pattern of control subjects with a more common "control" disease. The control location pattern is used as a null model of no clustering and should reflect the spatial pattern of the population-at-risk.
Diggle (1990) evaluates the pattern of laryngeal cancer near an industrial incinerator in Lancashire, England. He compares this pattern with the distribution of lung cancer in the area, the control. Diggle and Rowlingson (1994) reanalyze the Lancashire data as well as childhood asthma in Derbyshire, England in relation to three industrial plants. They found no effect of two of the three plants, but there was "modest evidence" for an association with one of the plants. ClusterSeer currently supports the investigation of a pattern around a single focus.
