Table 2.

Effect modification of the ERR of incident thyroid cancer per gray of exposure according to selected characteristics.

Table 2. Effect modification of the ERR of incident thyroid cancer per gray of exposure according to selected characteristics.
Characteristic		PY (n = 73,004)		Cases (n = 65)		ERR per gray (95% CI)
Sex
Male		35,240		28		1.20 (0.03 to 6.74)a
Female		37,764		37		2.66 (0.46 to 12.49)
p-Valueb						0.40
Age at exposure (years)
0 to < 4		21,236		18		7.43 (< 1.67 to NE)c
4 to < 12		34,941		31		1.57 (–0.02 to 8.51)
12 to < 18		16,827		16		0.69 (< –0.04 to 6.31)
p-Value						0.40
Attained age (years)
< 22		26,440		16		2.08 (0.10 to > 13.65)d
22 to < 30		34,374		25		1.83 (0.01 to 11.97)
30 to < 40		12,190		24		0.74 (< 0.06 to 4.95)
p-Value						0.71
Time since exposure (years)e
< 16.7		1,209		21		2.85 (0.08 to 44.31)c
16.7 to < 20.0		40,385		24		1.31 (0.05 to 7.18)
20.0–22.4		31,409		20		3.69 (0.43 to 42.80)
p-Value						0.60
Oblast of residencef
Zhytomyr		20,254g		11		0.06 (< –0.02 to 1.08)h
Kyiv		14,710		15		2.70 (0.27 to 27.52)
Chernihiv		37,988		39		4.07 (0.95 to 16.80)
p-Value						0.008
Oblast of residence in 1986f
Zhytomyr		20,816		12		0.08 (< –0.01 to 1.27)h
Kyiv		13,443		11		1.22 (–0.02 to 12.59)
Chernihiv		38,746		42		5.20 (1.45 to 21.40)
p-Value						0.005
Iodine prophylaxis in May–June 1986f
No		51,674g		50g		2.11 (0.36 to 9.28)c
Yes		18,154		12		1.03 (< 0.08 to 9.84)
p-Value						0.56
Diffuse goiterf,i
No		57,122		45		1.78 (0.33 to 6.41)c
Yes		15,882		20		2.07 (0.03 to > 28.4)
p-Value						0.89
Serum TG (ng/mL)f
< 15.0		30,845g		20g		1.58 (< 0.32 to 13.77)c
15.0 to < 31.0		20,687		21		1.89 (0.18 to 12.21)
31.0–643.0		16,108		21		2.58 (0.16 to 34.73)
p-Value						0.92
Serum TSH (mIU/L)f
< 1.3		17,265g		14g		2.61 (0.06 to 30.89)c
1.3 to < 2.5		33,750		28		1.97 (0.06 to 12.30)
2.5–25.4		19,448		21		1.05 (0.02 to 7.60)
p-Value						0.74
Urinary iodine (μg/L)f
< 34.0		22,674g		20g		0.60 (< –0.002 to 5.69)c
34.0 to < 50.0		15,573		18		3.72 (0.36 to 52.48)
50.0–750.3		28,153		22		2.23 (0.16 to 18.49)
p-Value						0.36
NE, not estimable. aAdjusted for attained age and oblast. bp-Value for tests of homogeneity of linear trends across categories of interest or 1 df interaction test between dose and continuous variable. cAdjusted for sex, attained age, and oblast. dAdjusted for sex, oblast, and time since exposure. eDifference between the exit date (date of thyroid surgery or last screening examination for those not operated upon) and date of the accident. fReported at interview or detected during the first screening examination. gPerson-years or cancer cases may not add up to column total because of missing values (excluded from analyses). hAdjusted for sex and attained age. iBased on palpation by endocrinologist and defined as grade 0, 1, or 2. In the analysis, grades 1 and 2 were combined as the “yes” category.