A case-control study of exposure to organophosphate flame retardants and risk of thyroid cancer in women

BMC Cancer

Table 2 Distribution of selected characteristics of the papillary thyroid cancer cases and controls

	Cases (n = 100)	Control (n = 100)
	N or %^a	N or (%)^a	p-value^b
Age			0.47
< 40	23	17
40–49	24	28
50–59	39	31
60–69	19	15
> =70	4	9
Years of education			0.009
High school or less	25	9
College/Technical school	47	55
Graduate/Professional school	25	35
Other	3	1
Family income			0.83
Below poverty level	6	5
Above poverty level	71	68
Unknown	23	27
BMI			0.18
< 25	32	38
25–29.99	32	38
> =30	36	24
Family history of thyroid cancer			0.39
No	49	49
Thyroid Cancer	16	10
Other Cancer	35	41
Thyroid disease			0.02
Yes	14	4
No	86	96
Smoking			0.76
Yes	29	32
No	71	68
Alcohol consumption			0.20
Yes	37	47
No	63	53
Tumor diameter			–
≤ 1 cm	47	–
> 1 cm and ≤ 2 cm	29	–
> 2 cm	22	–
Not available	2	–

^aThe frequency and percentage are equivalent because the number of cases and controls each equals 100
^bBased on chi-squared test or Fisher’s exact test when ≥1 cell has an expected frequency ≤ 5

ISSN: 1471-2407