Table 3 Factors associated with under-replaced and over-replaced thyroid status using stepwise logistic regression

Under-Replacement (TSH > 3.7 mIU/L)^a

 Gender

  Female

Ref

-

  Male

1.25 (1.03 to 1.51)

0.02

 BMI

  Underweight

1.42 (0.96 to 2.08)

0.077

  Normal

Ref

-

  Overweight

1.01 (0.83 to 1.24)

0.885

  Obese

1.34 (1.08 to 1.66)

0.008

 Follow-up period

  Within one year (≤ 12 months)

0.57 (0.44 to 0.74)

 < 0.001

  Between 13 and 24 Months

Ref

-

Index daily thyroxine dose per kg BW

1.22 (1.01 to 1.48)

0.047

Number of thyroid function tests

1.22 (1.16 to 1.28)

 < 0.001

Over-Replacement (TSH < 0.65 mIU/L)^a

 BMI

  Underweight

0.48 (0.20 to 1.02)

0.074

  Normal

Ref

-

  Overweight

1.16 (0.85 to 1.58)

0.343

  Obese

1.29 (0.91 to 1.83)

0.149

 Follow-up period

  Within one year (≤ 12 months)

0.62 (0.41 to 0.97)

0.033

  Between 13 and 24 months

Ref

-

 Index daily thyroxine dose per kg BW

2.72 (1.99 to 3.75)

 < 0.001

 Number of thyroid function tests

1.21 (1.12 to 1.31)

 < 0.001