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Table 2 Thyroid volume (ml) estimates with 95% confidence intervals from the linear regression models, Belarus, 1996-2001

From: Association between exposure to radioactive iodine after the Chernobyl accident and thyroid volume in Belarus 10-15 years later

Explanatory parameter Thyroid volume estimates
Overall (N = 10,703) Younger than 18 years at screening (n = 3312) 18 years or older at screening (n = 7391)
Radiationa
 0.0005 Gyb Reference Reference Reference
 0.001 Gy 0.129 (0.050, 0.208) 0.120 (−0.016, 0.256) 0.123 (0.024, 0.222)
 0.05 Gy 1.073 (0.488, 1.658) 0.956 (−0.080, 1.992) 1.035 (0.316, 1.754)
 0.1 Gy 1.225 (0.584, 1.866) 1.075 (−0.073, 2.222) 1.190 (0.407, 1.972)
 0.15 Gy 1.297 (0.637, 1.957) 1.125 (−0.065, 2.314) 1.266 (0.464, 2.067)
 0.5 Gy 1.385 (0.742, 2.027) 1.144 (−0.041, 2.330) 1.390 (0.620, 2.159)
 1 Gy 1.326 (0.728, 1.925) 1.057 (−0.053, 2.166) 1.375 (0.660, 2.089)
 2 Gy 1.206 (0.614, 1.798) 0.938 (−0.126, 2.003) 1.323 (0.589, 2.056)
 4 Gy 1.135 (0.234, 2.035) 0.950 (−0.435, 2.335) 1.352 (0.091, 2.612)
 4.5 Gy 1.146 (0.114, 2.178) 0.990 (−0.550, 2.530) 1.383 (−0.084, 2.851)
  P < 0.001c P = 0.247c P < 0.001c
Sex
 Female Reference Reference Reference
 Male 2.052 (1.892, 2.213) 0.369 (0.120, 0.617) 2.779 (2.578, 2.980)
  P < 0.001 P = 0.004 P < 0.001
Oblast at screening
 Minsk Reference Reference Reference
 Gomel −1.230 (−1.444, −1.016) − 1.094 (− 1.404, −0.784) −1.223 (− 1.502, −0.945)
  P < 0.001 P < 0.001 P < 0.001
 Otherd 0.680 (0.385, 0.976) 0.689 (0.216, 1.162) 0.733 (0.365, 1.102)
  P < 0.001 P = 0.004 P < 0.001
Age at screening (years)
 Group median agee Reference Reference Reference
 1 year increase 0.380 (0.365, 0.396) 0.845 (0.758, 0.931) 0.235 (0.208, 0.261)
 2 years increase 0.714 (0.683, 0.746) 1.495 (1.269, 1.721) 0.455 (0.401, 0.509)
 5 years increase 1.437 (1.346, 1.529) 1.032 (0.847, 1.217)
 7 years increase 1.687 (1.533, 1.840) 1.346 (1.012, 1.681)
  P < 0.001 P < 0.001 P < 0.001
  1. aHolding all covariates at their reference values, the mean estimated thyroid volume at reference dose 0.0005 Gy (the lowest dose in the study) was 11.0 ml overall, 9.0 ml in the subgroup < 18 years, and 11.5 ml in the subgroup ≥18 years. Thyroid volume estimates at specific doses are an increase above the reference thyroid volumes
  2. bLowest dose in the study is 0.0005 Gy
  3. cP-value for the association between thyroid dose and thyroid volume using linear regression model with three power terms for dose (dose1/1 + dose1/2 + dose1/4)
  4. dIncludes Brest, Grodno, Mogilev, and Vitebsk oblasts
  5. eMedian age (reference): 21 years overall, 15 years in the subgroup < 18 years, and 24 years in the subgroup ≥18 years