Table 1.

Demographic and clinical characteristics of leukemia (and ALL) patients.

Characteristics	Leukemia				ALL
	Cases		Controls		Cases		Controls
	N	%	N	%	N	%	N	%
Total	559	100	4433	100	425	100	3350	100
Sex of case/control child
Male	334	59.7	2640	59.6	250	58.8	1961	58.5
Female	225	40.3	1793	40.4	175	41.2	1389	41.5
Age at diagnosis (in years) of case child
0–4	156	27.9			135	31.8
5–9	188	33.6			145	34.1
10–13	150	26.8			107	25.2
14–15	65	11.6			38	8.9
Age at census (in years) of case/control child
<1	76	13.6	616	13.9	60	14.1	487	14.5
1–4	234	41.9	1848	41.7	193	45.4	1511	45.1
5–9	167	29.9	1327	29.9	119	28.0	944	28.2
10–13	75	13.4	592	13.4	48	11.3	373	11.1
14–15	7	1.3	50	1.1	5	1.2	35	1.0
Age of the mother at child birth (in years)
<25	106	19.0	893	20.3	70	16.5	672	20.2
25–29	203	36.4	1732	39.3	154	36.4	1308	39.3
30–34	174	31.2	1263	28.7	135	31.9	950	28.6
35+	74	13.3	514	11.7	64	15.1	396	11.9
Missing	2		31		2		24
Age of the father at child birth (in years)
<25	50	9.5	331	7.9	32	8.0	234	7.4
25–29	136	25.8	1283	30.7	100	25.0	976	30.8
30–34	185	35.1	1487	35.6	138	34.5	1125	35.5
35+	156	29.6	1075	25.7	130	32.5	831	26.2
Missing	32		257		25		184
Total number of children in household
1	144	25.8	1099	24.8	109	25.6	850	25.4
2	268	47.9	2137	48.2	205	48.2	1599	47.7
3	102	18.2	851	19.2	77	18.1	642	19.2
4+	45	8.1	346	7.8	34	8.0	259	7.7
Number of children in household who are older than case or control
0	275	49.2	2179	49.2	206	48.5	1632	48.7
1	206	36.9	1631	36.8	158	37.2	1221	36.4
2+	78	14.0	623	14.1	61	14.4	497	14.8
Nationality
Swiss	438	78.4	3481	78.5	341	80.2	2629	78.5
Non-Swiss	121	21.6	952	21.5	84	19.8	721	21.5
Language region
German	427	76.4	3237	73.0	324	76.2	2447	73.0
French	112	20.0	1034	23.3	90	21.2	794	23.7
Italian	20	3.6	162	3.7	11	2.6	109	3.3
Census
1990	300	53.7	2376	53.6	218	51.3	1724	51.5
2000	259	46.3	2057	46.4	207	48.7	1626	48.5

ALL indicates acute lymphoblastic leukemia.