Results: A total of 801 patients were included; 591 having received RAI and 210 surgery (total thyroidectomy in 176, near-total in 32 and subtotal in 2 patients). European patients comprised 58.2% of the total group and M aori 28.8%. Overall, at one year after definitive treatment 47.8% of all patients were euthyroid. This increased to 53.8%, 54.3% and 61.7% at 2, 5 and 10 years, respectively. Comparison of thyroid hormone status between surgical and RAI patients showed more patients were euthyroid following surgery at one and two years post-treatment (53.1% vs. 46.0% and 62.3% vs. 51.1%, respectively). There were no differences between the two groups in the percentage of patients who were euthyroid at 5 and 10 years. Less M aori were euthyroid when compared to Europeans at all time points (1 year 30% vs. 58%, 2 years 42% vs. 60%, 5 years 32% vs. 66% and 10 years 49% vs 70%, <0.0005 at all points).
Conclusion:Following surgery more patients were euthyroid in the first 2 years but there was no difference in the percentage of patients who were euthyroid at 5 and 10 years following treatment in the surgical group compared with the patients treated with RAI. M aori were significantly less likely to be euthyroid when compared with their European counterparts, and this inequality was present at all-time points. Overall, long-term the number of patients who were euthyroid was lower than one would expect. This indicates a need for improved care of patients who have undergone definitive therapy for Graves' disease, with a particular focus on M aori in order to reduce this disparity.
References1. Brownlie, B.E. and J.E. Wells, The epidemiology of thyrotoxicosis in New Zealand: incidence and geographical distribution in north Canterbury, 1983-1985. Clinical Endocrinology, 1990