Table 4.
Difference between measured and predicted 24 h urinary iodine excretion (UIE), SAGE South Africa Wave 2 (2015).
| Prediction Equation | n | Median (IQR) | Median (IQR) Difference † | Mann Whitney Test p Value |
Spearman Correlation Coefficient p Value |
EAR ‡ Below (%) |
|---|---|---|---|---|---|---|
| Mage equation (µg/day) mUIE PrUIE |
428 |
124 (137) 105 (117) |
17.8 (108) | 0.000 |
0.402 0.000 |
49.5 * |
| Tanaka equation (µg/day) mUIE PrUIE |
454 |
124 (136) 130 (136) |
−3.2 (117) | 0.399 |
0.413 0.000 |
39.3 * |
| Kawasaki equation (µg/day) mUIE PrUIE |
454 |
124 (136) 122 (131) |
4.1 (110) | 0.443 |
0.425 0.000 |
41.3 * |
PrUIE, Predicted Urinary Iodine Excretion (µg/day); mUIE, measured 24 h Urinary Iodine Excretion (µg/day). † mUIE minus PrUIE; ‡ EAR = 95 µg/day. Percentage below EAR is shown for each of the equations (X2 test compared to mUIE (41%); * p < 0.001). Mage n is lower as equation requires additional data on ethnicity (n = 26 with missing ethnicity data).