Table 2 Refractory odds ratios for selected baseline characteristics in univariable and multivariable analyses

Age, year

 ≥ 36

39.4 (65/165)

Reference

Reference

 < 36

59.1 (107/181)

2.2 (1.4–3.4)

1.7 (1.1–2.7)

Current smoking, n (%)

 Yes

61.1 (22/36)

1.7 (0.8–3.4)

 No

48.4 (150/310)

Reference

GO, n (%)

 Yes

65.9 (56/85)

2.4 (1.4–4.0)

2.5 (1.4–4.5)

 No

44.4(116/261)

Reference

Reference

Initial goiter size (cm³)

 ≥ 11.5

56.5 (160/283)

5.5 (2.8–10.8)

4.6 (2.2–9.5)

 < 11.5

19.0 (12/63)

Reference

Reference

Initial fT3 (pmol/L)

 ≥ 31.3

62.3 (76/122)

2.2 (1.4–3.5)

1.3 (0.6–2.7)

 < 31.3

42.9 (96/224)

Reference

Reference

Initial fT4 (pmol/L)

 ≥ 67.7

59.6 (90/151)

2.0 (1.3–3.1)

1.2 (0.6–2.5)

 < 67.7

42.1 (82/195)

Reference

Reference

Initial TPOAb (IU/mL)

 ≥ 67.7

53.1 (111/209)

1.4 (0.9–2.2)

 < 67.7

44.5 (61/137)

Reference

Initial TgAb (IU/mL)

 ≥ 660.0

58.6 (34/58)

1.5 (0.9–2.7)

 < 660.0

47.9 (138/288)

Reference

Initial TRAb (IU/L)

 ≥ 17.5

68.6 (81/118)

3.3 (2.1–5.3)

2.3 (1.4–3.9)

 < 17.5

39.9 (91/228)

Reference

Reference