Women with non-toxic goitre were defined as simultaneously having a non-toxic goitre diagnostic code [E04.x (Other non-toxic goitre)] and a thyroid test code (thyroid stimulating hormone (TSH), free T3, free T4, anti-thyroid antibody, anti-thyroglobulin antibody, and neck ultrasound) (Table 1). Here, TG is linked to thyroid gland disorder.