Table 2.

Descriptive Characteristics of Cases and Controls Identified From the Cohort of Ukrainian Chornobyl Cleanup Workers During Follow-Up (1986–2000).

	Cases	(%)	Controls	(%)	DOFb	pvalueb
Total	71	100.0	501	100.0
Year of birth					4	0.89
1923–1929	4	5.6	35	7.0
1930–1939	24	33.8	144	28.7
1940–1949	18	25.4	149	29.7
1950–1959	21	29.6	146	29.1
1960–1965	4	5.6	27	5.4
Areas of study					5	0.89
Cherkasy oblast	3	4.2	40	8.0
Chernihiv oblast	6	8.5	44	8.8
Dnipropetrovsk oblast	16	22.5	96	19.2
Kharkiv oblast	8	11.3	67	13.4
Kyiv oblast	14	19.7	102	20.4
Kyiv City	24	33.8	152	30.3
Type of residence					1	0.69
Urban	52	73.2	405	80.8
Rural	14	19.7	96	19.2
Unknown	5	7.0	0	0.0
Education					3	0.33
8 years or less	9	12.7	74	14.8
High school	21	29.6	210	41.9
Trade school	18	25.4	112	22.4
College	18	25.4	102	20.4
Unknown	5	7.0	3	0.6
Proxy interviews					1	<0.01
No	29	40.8	465	92.8
Yes	42	59.2	36	7.2
Cell Type
Non–CLLa	32	45.1				NAd
CLL	39	54.9

^aCLL, chronic lymphocytic leukemia

^bDOF, degrees of freedom from the chi-square test

^cp value of the chi-square test

^dNA, not applicable