Table 1.

Cluster characteristics by detection method and study area scale

	Local Moran’s I Statistic			Kulldorff’s Scan Statistic
	State	Region	County	State	Region	County
Reference syphilis incidence rate by study area scale, cases per 100,000 person years	3.2	4.1	8.9	3.2	4.1	8.9
Cluster characteristics
Proportion of Mecklenburg tracts included in cluster, n (%)	78 (54.2)	67 (46.5)	26 (18.1)	90 (62.5)	77 (53.5)	24 (16.7)
Cluster incidence, cases per 100,000 person years	14.8	17.0	30.3	14.1	15.9	28.6
Total population in cluster	359734	290895	77662	393656	330076	85507
Total cases in cluster	454	410	179	465	434	190
Minimum rate for tracts included in cluster	4.3	5.7	13.7	0.0	0.0	0.0