Table 3.

Odds ratios (OR) and 95% confidence intervals (CI) for prevalence of hyperthyroidism: effects of I-131 thyroid dose.

Model	Dose (Gy)	Case (76)	Noncase (11,777)	Rate Per03	ORa	95% CI	Test for trend / heterogeneityb P
(a) All subjects combined
Linear			EOR/Gy = 0.02			NA,0.53	0.90
7 categ.	< 0.1	24	3729	6.39	1		0.94
	0.1–0.25	18	2769	6.46	1.11	0.58,2.08
	0.25–0.50	12	1987	6.00	1.15	0.54,2.36
	0.50–1	11	1443	7.57	1.61	0.72,3.41
	1–2.5	7	1232	5.65	1.39	0.51,3.38
	2.5–5	3	403	7.39	1.65	0.37,5.33
	≥ 5	1	214	4.65	1.38	0.07,7.48
3 categ.	<0.1	24	3729	6.39	1		0.45
	0.1–0.5	30	4756	6.27	1.13	0.64,2.00
	≥ 0.5	22	3292	6.64	1.53	0.77,3.01
dichotomous	<0.5	54	8485	6.32	1		0.23
	≥ 0.5	22	3292	6.64	1.41	0.79,2.45
(b) Male
Linear			EOR/Gy = −0.025c			NA	0.61
7 categ.	< 0.1	6	1794	3.33	1		0.83
	0.1–0.25	7	1435	4.85	1.54	0.51,4.83
	0.25–0.50	5	1060	4.69	1.54	0.43,5.28
	0.50–1	3	786	3.80	1.25	0.25,4.94
	1–2.5	2	669	2.98	1.10	0.15,5.08
	2.5–5	0	205	0	0.00	NA
	≥ 5	0	114	0	0.00	NA
3 categ.	< 0.1	6	1794	3.33	1		0.57
	0.1–0.5	12	2495	4.79	1.55	0.59,4.52
	≥ 0.5	5	1774	2.81	1	0.27,3.54
dichotomous	<0.5	18	4289	4.18	1		0.49
	≥ 0.5	5	1774	2.81	0.75	0.24,1.98
(c) Female
Linear			EOR/Gy = 0.22			−0.10,1.23	0.31
7 categ.	< 0.1	18	1935	9.22	1		0.71
	0.1–0.25	11	1334	8.18	0.94	0.42,2.01
	0.25–0.50	7	927	7.49	0.98	0.37,2.35
	0.50–1	8	657	12.03	1.82	0.71,4.32
	1–2.5	5	563	8.80	1.58	0.48,4.38
	2.5–5	3	198	14.93	2.38	0.51,8.03
	≥ 5	1	100	9.90	2.20	0.12,12.56
3 categ.	< 0.1	18	1935	9.22	1		0.17
	0.1–0.5	18	2261	7.90	0.96	0.48,1.91
	≥ 0.5	17	1518	11.07	1.83	0.85,3.93
dichotomous	<0.5	36	4196	8.51	1		0.06
	≥ 0.5	17	1518	11.07	1.89	0.97,3.54

^aAll analyses performed with adjustment for gender, age at examination by gender, place of residency, period of examination, ATPO level, thyroid volume and ultrasound-detected nodules.

^bBased on the LRT for the dose response vs no dose effect.

^cEstimated with the parameter space constrained on >-max(dose)⁻¹.