Table 2 Univariate analyses with respect to clinical factors and the risk of HT
Variable | Univariate analysis | |
|---|---|---|
HR (95% CI) | p value | |
Sex | ||
 Male |  |  |
 Female | 1.999 (1.468–2.722) | 0.000* |
Age | ||
 Per year increase | 0.976 (0.964–0.988) | 0.000* |
Chemotherapy | ||
 Yes |  |  |
 No | 1.587 (1.024–2.459) | 0.039* |
Neck surgery | ||
 Yes |  |  |
 No | 1.306 (0.727–2.347) | 0.371 |
Thyrotoxicosis | ||
 Yes |  |  |
 No | 0.609 (0.440–0.844) | 0.003* |
T classification | ||
 T1–T2 |  |  |
 T3–T4 | 1.308 (0.968–1.768) | 0.08 |
N classification | ||
 N0–N1 |  |  |
 N2–N3 | 1.524 (1.086–2.137) | 0.015* |
UICC 2010 stage | ||
 I–II |  |  |
 III–IV | 1.016 (0.679–1.522) | 0.937 |
Thyroid volume, per cm3 increase | 0.905 (0.877–0.934) | 0.000* |
Pituitary volume, per cm3 increase | 0.870 (0.634–1.192) | 0.386 |