Space-time clustering analyses of type 1 diabetes in children from north-east England: support for an infectious aetiology?

Table 1 Results of K-function analyses of space-time clustering for cases of type 1 diabetes diagnosed in north-east England during the period 1990-2007^a,b

Group	Geographical distance^c	NN threshold^d
All case pairs	P = 0.240	P = 0.089
Case pairs aged 0-4 years only	P = 0.343	P = 0.541
Case pairs aged 5-9 years only	P = 0.112	P = 0.187
Case pairs aged 10-14 years only	P = 0.318	P = 0.478
"Male: any" case pairs	P = 0.453	P = 0.190
"Female: any" case pairs	P = 0.182	P = 0.017
"More densely populated: any" case pairs	P = 0.211	P = 0.044
"Less densely populated: any" case pairs	P = 0.350	P = 0.226

^aCases are temporally close if dates of diagnosis differ by <t where t varies from 0.1 year to 1.5 years in steps of 0.1 year;
^bP-value obtained by simulation (999 runs) with dates of diagnosis randomly re-allocated to the cases in the analysis;
^cCases are spatially close if locations at diagnosis differ by <s where s varies from 0.5 km to 7.5 km in steps of 0.5 km;
^dCases are spatially close if either is within the distance to the N^th NN of the other where N varies from 14 to 28 in steps of 1.

ISSN: 1476-069X