Table 3.

Thyroid cancer incidence in Sicily: odds ratio by environmental characteristic.

Environmental characteristic	No. of residents	Females			Males			p*
		no. of cases	OR	(95% C.I.)	no. of cases	OR	(95% C.I.)
Volcanic environment
Yes (Catania Province)	1,059,811	599	2.242	2.020–2.488	130	2.052	1.652–2.565	<0.001
No (Sicily without Catania Province)	3,920,541	985	1		236	1
Urban	3,846,823	1252	1.056	0.929–1.200	293	1.118	0.852–1.465	N.S.
Rural	1,133,529	332	1		73	1
Industrial	364,110	93	0.998	0.805–1.237	26	1.174	0.773–1.784	N.S.
Non-Industrial	4,616,242	1491	1		340	1
Iodine deficiency	208,512	68	1.163	0.900–1.502	18	1.468	0.897–2.401	N.S.
Iodine sufficiency	4,771,840	1516	1		348	1

*Poisson regression adjusted for all environmental characteristic.