Table 5 Univariate and multivariate statistical analysis of disease free interval

Gender (male vs. female)

0,188

0,79

0,55–1,12

Age (years) (<54 vs. ≥55)

0,001

1,65

1,22–2,22

Disease duration (years) (<5 vs. ≥5)

0,073

0,75

0,55–1,02

T stadium (T1 and T2 vs. T3 and T4)

0,337

0,86

0,64–1,16

N stadium (N0 and Nx vs. N1a and N1b)

0,438

0,70

0,29–1,71

Tumor type (minimally vs. widely invasive)

0,485

0,89

0,65–1,22

Tumor size (mm) (≤39 vs. >40)

0,723

1,06

0,77–1,44

Capsular invasion (positive vs. no or minimal)

0,001

1,71

1,23–2,37

Vascular invasion (positive vs. no or minimal)

0,002

1,64

1,19–2,23

Number of tumor focuses (one vs. multicentric)

0,364

0,84

0,58–1,22

Affection of both lobes (yes vs. no)

0,123

1,33

0,92–1,9

Regional tumor infiltration (yes vs. no)

0,19

1,37

0,86–2,18

Primary procedure (total thyroidectomy vs. less than total)

0,335

1,18

0,84–1,63

Type of procedure overall (total thyroidectomy vs. less than total)

0,254

1,22

0,86–1,71

Surgeon’s experience (years) (<10 vs. 10+)

0,001

0,58

0,42–0,79

Radioiodine ablation (yes vs. no)

0,026

0,69

0,49–0,95

Diabetes mellitus (yes vs. no)

0,097

0,59

0,32–1,09

Hypertension (yes vs. no)

0,009

0,67

0,5–0,9

Other malignancies (yes vs. no)

0,001

0,45

0,27–0,73

Thyroglobulin (ng/mL) (<300 vs. >300)

0,976

1,01

0,55–1,83