Table 3. Multivariate analysis of risk factors for central lymph node metastasis.
| Risk factors | OR | 95% CI | P value |
|---|---|---|---|
| Gender (male vs. female) | 5.315 | 2.881–9.806 | <0.001 |
| Age (years) | |||
| <45 | 1.792 | 1.104–2.907 | 0.018 |
| ≥45 | |||
| Tumor size (cm) | |||
| <1 | |||
| ≥1 | 7.757 | 4.716–12.760 | <0.001 |
| Tumor location | |||
| Upper | |||
| Middle/lower | 8.102 | 4.213–15.582 | <0.001 |
| Ultrasound feature | |||
| Intra-nodular vascularity (yes vs. no) | 2.570 | 1.569–4.209 | <0.001 |
| Microcalcification (yes vs. no) | 2.639 | 1.354–5.141 | 0.004 |
| Irregular shape (yes vs. no) | 2.398 | 1.199–4.794 | 0.013 |
| Infiltrative margin (yes vs. no) | 2.559 | 1.202–5.447 | 0.015 |
| Multifocality (yes vs. no) | 1.844 | 1.079–3.153 | 0.025 |
| Extrathyroidal extension (yes vs. no) | 5.875 | 1.953–17.674 | 0.002 |
OR, odds ratio; CI, confidence interval.