Background: The optimum therapy for Graves' disease (GD) is chosen following discussion between physician and patient regarding benefits, drawbacks, potential side effects, and logistics of the various treatment options, and it takes into account patient values and preferences. This cohort study aimed to provide useful information for this discussion regarding the usage, efficacy, and adverse-effect profile of radioactive iodine (RAI), antithyroid drugs (ATDs), and thyroidectomy in a tertiary healthcare facility.
Methods: The cohort included consecutive adults diagnosed with GD from January 2002 to December 2008, who had complete follow-up after treatment at the Mayo Clinic, Rochester, Minnesota. Data on treatment modalities, disease relapses, and adverse effects were extracted manually and electronically from the electronic medical records. Kaplan-Meier analyses were performed to evaluate the association of treatments with relapse-free survival.
Results: The cohort included 720 patients with a mean age of 49.3 years followed for a mean of 3.3 years. Of these, 76.7% were women and 17.1% were smokers. The initial therapy was RAI in 75.4%, ATDs in 16.4%, and thyroidectomy in 2.6%, while 5.6% opted for observation. For the duration of follow-up, ATDs had an overall failure rate of 48.3% compared with 8% for RAI (hazard ratio = 7.6; p < 0.0001). Surgery had a 100% success rate; 80% of observed patients ultimately required therapy. Adverse effects developed in 43 (17.3%) patients treated with ATDs, most commonly dysgeusia (4.4%), rash (2.8%), nausea/gastric distress (2.4%), pruritus (1.6%), and urticaria (1.2%). Eight patients treated with RAI experienced radiation thyroiditis (1.2%). Thyroidectomy resulted in one (2.9%) hematoma and one (2.85%) superior laryngeal nerve damage, with no permanent hypocalcemia.
Conclusions: RAI was the most commonly used modality within the cohort and demonstrated the best efficacy and safety profile. Surgery was also very effective and relatively safe in the hands of experienced surgeons. While ATDs allow preservation of thyroid function, a high relapse rate combined with a significant adverse-effect profile was documented. These data can inform discussion between physician and patient regarding choice of therapy for GD.
Keywords: Graves' disease; antithyroid drugs (ATDs); comparative effectiveness; hyperthyroidism; radioactive iodine (RAI); thyroidectomy.