Table 2.

Characteristics of the significant (p < 0.05) high- and low-risk clusters in Great Britain, as identified by the spatial scan statistic based on a Bernoulli probability model and using a circular scanning window to include 50% of the population at risk (as illustrated in Figure 4)

Cluster	Observed Cases	Expected Cases	Total holdings in cluster	Relative risk	P-value
Most likely cluster	104	43	216	2.892	0.001
Secondary cluster	2	37	186	0.049	0.001