Table 2.
Poisson regressions.
| Substituted Data (Dataset A)a N = 253346 |
Complete Data (Dataset B)b N = 113120 |
|||||||
|---|---|---|---|---|---|---|---|---|
| Model 1c |
Model 2d |
Model 1 |
Model 2 |
|||||
| DRRe | 95% CIf | DRR | 95% CI | DRR | 95% CI | DRR | 95% CI | |
| External radiation exposure (ERE): mSv | ||||||||
| <1 reference | 1 | – | 1 | – | 1 | – | 1 | – |
| 1+ | 1.557 | 0.715–3.394 | 1.596 | 0.726–3.512 | 1.677 | 0.746–3.773 | 1.669 | 0.743–3.748 |
| Sex | ||||||||
| Boy | 1 | – | 1 | – | 1 | – | 1 | – |
| Girl | 1.241 | 0.822–1.872 | 1.236 | 0.817–1.870 | 0.950 | 0.529–1.707 | 0.960 | 0.534–1.728 |
| Age group (years) | ||||||||
| [3,9)g | – | – | – | – | – | – | – | – |
| [9,12) | 1 | – | 1 | – | 1 | – | 1 | – |
| [12,15) | 2.280 | 1.090–4.768 | 2.289 | 1.094–4.788 | 1.959 | 0.590–6.508 | 1.965 | 0.592–6.527 |
| [15,18) | 3.598 | 1.753–7.388 | 3.635 | 1.770–7.465 | 4.176 | 1.360–12.820 | 4.214 | 1.372–12.941 |
| [18,25) | 8.505 | 4.152–17.422 | 8.353 | 4.060–17.184 | 11.706 | 3.996–34.290 | 11.802 | 4.021–34.642 |
| Overweight | ||||||||
| No | 1 | – | 1 | – | 1 | – | 1 | – |
| Yes | 1.299 | 0.819–2.060 | 1.312 | 0.827–2.083 | 1.250 | 0.631–2.476 | 1.247 | 0.629–2.471 |
| Past medical history (PMH): | ||||||||
| No | – | – | 1 | – | – | – | 1 | – |
| Yes | – | – | 1.381 | 0.803–2.375 | – | – | 1.269 | 0.588–2.741 |
| Family history of thyroid cancer (FTC): | ||||||||
| No | – | – | 1 | – | – | – | 1 | – |
| Yes | – | – | 0.869 | 0.401–1.883 | – | – | 1.155 | 0.454–2.939 |
| Frequency of eating seafood (FESF): | ||||||||
| 0 or 1–2/week | – | – | 1 | – | – | – | 1 | – |
| 6–7 or 3–4/week | – | – | 1.158 | 0.702–1.912 | – | – | 0.944 | 0.452–1.973 |
| Frequency of eating seaweed (FESW): | ||||||||
| 0 or 1–2/week | – | – | 1 | – | – | – | 1 | – |
| 6–7 or 3–5/week | – | – | 0.936 | 0.538–1.629 | – | – | 1.272 | 0.610–2.656 |
| Six districts | ||||||||
| North (reference) | 1 | – | 1 | – | 1 | – | 1 | – |
| Central | 0.792 | 0.447–1.402 | 0.795 | 0.449–1.407 | 0.626 | 0.275–1.426 | 0.632 | 0.277–1.441 |
| South | 0.926 | 0.292–2.938 | 0.952 | 0.299–3.031 | 0.594 | 0.126–2.813 | 0.601 | 0.127–2.843 |
| Soso | 1.561 | 0.623–3.910 | 1.451 | 0.567–3.712 | 1.448 | 0.547–3.837 | 1.461 | 0.551–3.868 |
| Iwaki | 1.374 | 0.539–3.503 | 1.404 | 0.546–3.607 | 0.669 | 0.198–2.267 | 0.679 | 0.201–2.299 |
| Aizu + Minami-Aizu | 1.257 | 0.440–3.597 | 1.306 | 0.453–3.763 | 0.898 | 0.245–3.288 | 0.924 | 0.253–3.381 |
a
Substituted Data (Dataset A)：for cases in which missing external radiation-dose data were substituted by the median dose of 6 districts in which each resident was at the accident.
b
Complete Data (Dataset B)：for cases in which external radiation-dose data were observed.
c
Model 1: The explanatory variables were: ERE + Sex + Age + Six districts + Overweight.
d
Model 2: The explanatory variables were: ERE + Sex + Age + Six districts + Overweight + PMH + FTC + FESF + FESW.
e
DRR: detection rate ratio.
f
95% CI: 95% Confidence Interval.
g
[a,b): the interval with greater than or equal to a and less than b.