Assessing spatio-temporal variability of risk surfaces using residential history data in a case control study of breast cancer

Table 3 Standardized difference of residences for premenopausal and postmenopausal breast cancer cases and controls by age groups;

Premenopausal	Case (n = 1328)	Control (n = 2270)	Standardized differences	No. of areas^a > 2SD	No. of areas^a > critical values^b
Ages 35–44 (n = 1889)	647	1242	-5.12–5.88	34	8
Ages 45–56 (n = 1709)	681	1028	-4.72–3.14	30	0
Postmenopausal	Case (n = 3484)	Control (n = 5616)	Standardized differences	No. of areas > 2SD	No. of areas > critical values
Ages 40–64 (n = 4916)	2115	2801	-3.52–3.77	49	0
Ages 65–79 (n = 4184)	1369	2815	-4.50–3.15	40	0

^a Areas refer to the rectangular grid overlaid on to the study area, ^b Critical values of 3.88 for premenopausal and 3.71 for postmenopausal residences.

ISSN: 1476-072X