Background: The treatment efficacy of antithyroid drug (ATD) therapy, radioactive iodine (131I), or surgery for Graves' hyperthyroidism is well described. However, there are a few reports on the long-term total outcome of each treatment modality regarding how many require levothyroxine supplementation, the need of thyroid ablation, or the individual patient's estimation of their recovery. Methods: We conducted a pragmatic trial to determine the effectiveness and adverse outcome in a patient cohort newly diagnosed with Graves' hyperthyroidism between 2003 and 2005 (n = 2430). The patients were invited to participate in a longitudinal study spanning 8 ± 0.9 years (mean ± standard deviation) after diagnosis. We were able to follow 1186 (60%) patients who had been treated with ATD, 131I, or surgery. We determined the mode of treatment, remission rate, recurrence, quality of life, demographic data, comorbidities, and lifestyle factors through questionnaires and a review of the individual's medical history records. Results: At follow-up, the remission rate after first-line treatment choice with ATD was 45.3% (351/774), with 131I therapy 81.5% (324/264), and with surgery 96.3% (52/54). Among those patients who had a second course of ATD, 29.4% achieved remission (vs. the 45.3% after the first course of ATD). The total number of patients who had undergone ablative treatment was 64.3% (763/1186), of whom 23% (278/1186) had received surgery, 43% (505/1186) had received 131I therapy, including 2% (20/1186) who had received both surgery and 131I. Patients who received ATD as first-line treatment and possibly additional ATD had 49.7% risk (385/774) of having undergone ablative treatment at follow-up. Levothyroxine replacement was needed in 23% (81/351) of the initially ATD treated in remission, in 77.3% (204/264) of the 131I treated, and in 96.2% (50/52) of the surgically treated patients. Taken together after 6-10 years, and all treatment considered, normal thyroid hormone status without thyroxine supplementation was only achieved in 35.7% (423/1186) of all patients and in only 40.3% of those initially treated with ATD. The proportion of patients that did not feel fully recovered at follow-up was 25.3%. Conclusion: A patient selecting ATD therapy as the initial approach in the treatment of Graves' hyperthyroidism should be informed that they have only a 50.3% chance of ultimately avoiding ablative treatment and only a 40% chance of eventually being euthyroid without thyroid medication. Surprisingly, 1 in 4 patients did not feel fully recovered after 6-10 years. The treatment for Graves' hyperthyroidism, thus, has unexpected long-term consequences for many patients.
Keywords: Graves' disease; antithyroid drugs; hyperthyroidism; long-term follow-up; radioiodine; recurrence; remission; thyroidectomy.