Calculate the percentage of the monthly readings that are strictly below the threshold of $0.40mU/L$.

Suggest two further steps or laboratory investigations the doctor should take to confirm whether the patient has permanent hyperthyroidism.

The doctor discusses a treatment option called carbimazole (an antithyroid medication) with the patient, providing her with the following information:

Information about Carbimazole treatment:

• Benefits: Reduces the synthesis of thyroid hormones to relieve symptoms such as anxiety, palpitations, tremors, and heat intolerance. Reduces long-term risks of heart failure and osteoporosis.
• Risks/Considerations:
  • Can cause bone marrow suppression (agranulocytosis), which is a life-threatening reduction in white blood cells. Patients must immediately report infections, fevers, or sore throats.
  • Can cause drug-induced liver injury (hepatotoxicity), particularly in individuals with compromised liver function.
  • Associated with an increased risk of congenital malformations (birth defects) if taken during early pregnancy.
  • Requires long-term periodic blood tests to monitor hormone levels, liver function, and full blood counts.

The patient is a 28-year-old female with moderate anxiety and hand tremors who is planning to start a family in the next year. She has a history of mild hepatic impairment from a previous viral infection.

Discuss the factors this specific patient should consider when making her decision about whether to start carbimazole treatment.