SETIL: Italian multicentric epidemiological case–control study on risk factors for childhood leukaemia, non hodgkin lymphoma and neuroblastoma: study population and prevalence of risk factors in Italy

Table 5 SETIL study prevalence of exposure to passive smoking among controls: maternal exposure during pregnancy and child’s exposure to environmental tobacco smoke, by child’s age, residence, and parental educational level

		Maternal exposure to environmental tobacco smoke during pregnancy
		Not exposed^a		<2.00 hours/day^a		2.00-3.99 hours/day^a		≥4.00 hours/day^a		Missing	TOTAL
		N	%	N	%	N	%	N	%	N	N
Total		710	68.8	122	11.8	103	10.0	97	9.4	12	1044
Education (Mother)	Less than high school	249	62.4	48	12.0	55	13.8	47	11.8	6	405
	High school	349	70.4	66	13.3	35	7.1	46	9.3	5	501
	University	110	81.5	8	5.9	13	9.6	4	3.0	1	136
	Missing	2		0		0		0		0	2
Residence	Northern Italy (excl. Lombardy)	180	72.6	28	11.3	18	7.3	22	8.9	2	250
	Lombardy	199	77.1	20	7.8	18	7.0	21	8.1	2	260
	Central Italy	179	70.7	22	8.7	26	10.3	26	10.3	4	257
	Southern Italy	152	55.7	52	19.0	41	15.0	28	10.3	4	277
		Exposure of children to environmental tobacco smoke (as total number of cigarettes)
		Not exposed ^a		<1000 cigarettes ^a		1000-6999 cigarettes ^a		≥7000 cigarettes ^a		Missing	Total
		N	%	N	%	N	%	N	%	N	N
Total		740	71.4	91	8.8	88	8.5	118	11.4	7	1044
Age	[0–2)	119	76.8	19	12.3	15	9.7	2	1.3	1	156
	[2–4)	255	73.1	41	11.7	25	7.2	28	8.0	2	351
	[4–6)	161	69.1	24	10.3	13	5.6	35	15.0	0	233
	[6–11)	205	68.3	7	2.3	35	11.7	53	17.7	4	304
Education (Both parents)	Both parents less than high school degree	283	61.1	52	11.2	51	11.0	77	16.6	3	466
	At least one high school degree	337	79.5	29	6.8	25	5.9	33	7.8	3	427
	At least one university degree	120	80.0	10	6.7	12	8.0	8	5.3	1	151
	Missing	0		0		0		0
Residence	Northern Italy (excl. Lombardy)	186	75.0	20	8.1	18	7.3	24	9.7	2	250
	Lombardy	211	81.1	22	8.5	11	4.2	16	6.1	0	260
	Central Italy	197	77.6	10	3.9	21	8.3	26	10.2	3	257
	Southern Italy	146	53.1	39	14.2	38	13.8	52	18.9	2	277

Percentages are calculated by row. Information on maternal exposure missing for 15 controls.
^a: Categories of exposure to Environmental Tobacco smoke are based on tertiles of exposure among exposed controls, rounded to the nearest half hour (maternal exposure) or to the nearest thousand (child’s exposure).

ISSN: 1824-7288