Long-Term Oncological Outcome Comparison between Intermediate- and High-Dose Radioactive Iodine Ablation in Patients with Differentiated Thyroid Carcinoma: A Propensity Score Matching Study

Table 4

Univariate and multivariate analyses of recurrence risk factors after propensity score matching.

	Univariate		Multivariate
	HR (95% CI)	value	HR (95% CI)	value
Age	0.960 (0.931–0.990)	0.009
Lymphatic invasion	2.645 (1.158–6.043)	0.021
Positive LNs	1.068 (1.024–1.114)	0.002
LN ratio
≤0.22	Ref.		Ref.
>0.22	3.222 (1.362–7.622)	0.008	2.915 (1.228–6.918)	0.015
Pre-op. serum Tg	1.002 (1.000–1.004)	0.046
≤10 ng/mL	Ref.
>10 ng/mL	3.652 (1.263–10.560)	0.017
Post-RAI serum Tg	1.018 (1.005–1.031)	0.006
≤1 ng/mL	Ref.
>1 ng/mL	3.125 (1.321–7.391)	0.009
≤10 ng/mL	Ref.		Ref.
>10 ng/mL	4.385 (2.034–9.451)	<0.001	3.976 (1.839–8.595)	<0.001

Data are expressed as hazard ratio (HR) and 95% confidence interval (CI). A value <0.05 was considered statistically significant. LN ratio is defined as the number of positive LNs/the number of harvested LNs. Tg ratio is defined as post-RAI Tg/preop Tg. Abbreviation: TT, total thyroidectomy; mRND, modified radical neck dissection; ETE, extrathyroidal extension; LN, lymph node; T, tumor; N, node; ATA, American thyroid association; pre-op, preoperative; post-RAI, after radioactive iodine therapy; Tg, thyroglobulin; TgAb, thyroglobulin antibody.