Table 4.

Relative risk (RR) of childhood hematological disease associated with magnetic field exposure from power lines ≥ 0.1 μT and ≥ 0.4 μT in Modena and Reggio Emilia municipalities, 1986-2007^a

Disease		< 0.1 μT		≥ 0.1 μT			≥ 0.4 μT
		cases/controls	RR	cases/controls	RR	95% CIb	cases/controls	RR	95% CIb
All hematological malignancies	Crude	62/251	1.00	2/5	1.7	0.3-9.4	1/2	2.4	0.1-42.6
	Adjustedc	36/184	1.00	2/5	2.4	0.4-15.0	1/2	2.8d	0.2-34.3d
All leukemias	Crude	44/181	1.00	2/3	3.2	0.4-23.4	1/2	2.4	0.1-42.6
	Adjustedc	27/129	1.00	2/3	6.7	0.6-78.3	1/2	2.1d	0.2-26.2d
Acute lymphoblastic leukemia	Crude	34/142	1.00	2/2	6.0	0.5-69.5	1/2	2.4	0.1-42.6
	Adjustedc	20/106	1.00	2/2	5.3d	0.7-43.5d	1/2	2.3d	0.2-29.1d
Hematological malignancies other than leukemia	Crude	18/70	1.00	0/2	-e	-e	0/0	-e	-e
	Adjustedc	9/55	1.00	0/2	-e	-e	0/0	-e	-e

^aRelative risk estimates calculated with conditional logistic regression, using exposure category < 0.1 μT as reference category

^b95% confidence interval

^cAdjusted for paternal educational attainment and income and for maternal educational attainment

^dRisk estimates computed with unconditional logistic regression, adjusting for age, sex, municipality, paternal educational attainment and income, and maternal educational attainment

^eNo statistically valid estimates yielded by both conditional and unconditional logistic regression