European Journal of Endocrinology www.eje-online.org © 2017 European Society of Endocrinology Printed in Great Britain Published by Bioscientifica Ltd. DOI: 10.1530/EJE-16-0986 External validation of the GREAT score to predict relapse risk in Graves’ disease: results from a multicenter, retrospective study with 741 patients Tristan Struja 1, *, Marina Kaeslin 1, *, Fabienne Boesiger 1, *, Rebecca Jutzi 1 , Noemi Imahorn 1 , Alexander Kutz 1 , Luca Bernasconi 2 , Esther Mundwiler 2 , Beat Mueller 1,3 , Mirjam Christ-Crain 3,4 , Fabian Meienberg 4 , Fahim Ebrahimi 4 , Christoph Henzen 3,5 , Stefan Fischli 5 , Marius Kraenzlin 3,4 , Christian Meier 3,4 and Philipp Schuetz 1,3 1 Medical University Department, Clinic for Endocrinology, Diabetes & Metabolism, 2 Department of Laboratory Medicine, Kantonsspital Aarau, Aarau, Switzerland, 3 Medical Faculty of the University of Basel, Basel, Switzerland, 4 Clinic for Endocrinology, Diabetes & Metabolism, University Hospital of Basel, Basel, Switzerland, and 5 Clinic for Endocrinology, Diabetes & Metabolism, Kantonsspital Luzern, Luzern, Switzerland *(T Struja, M Kaeslin and F Boesiger contributed equally to this work) Abstract Context: First-line treatment in Graves’ disease is often done with antithyroid agents (ATD), but relapse rates remain high making defnite treatment necessary. Predictors for relapse risk help guiding initial treatment decisions. Objective: We aimed to externally validate the prognostic accuracy of the recently proposed Graves’ Recurrent Events After Therapy (GREAT) score to predict relapse risk in Graves’ disease. Design, setting and participants: We retrospectively analyzed data (2004–2014) of patients with a frst episode of Graves’ hyperthyroidism from four Swiss endocrine outpatient clinics. Main outcome measures: Relapse of hyperthyroidism analyzed by multivariate Cox regression. Results: Of the 741 included patients, 371 experienced a relapse (50.1%) after a mean follow-up of 25.6 months after ATD start. In univariate regression analysis, higher serum free T 4 , higher thyrotropin-binding inhibitor immunoglobulin (TBII), younger age and larger goiter were associated with higher relapse risk. We found a strong increase in relapse risk with more points in the GREAT score from 33.8% in patients with GREAT class I (0–1 points), 59.4% in class II (2–3 points) with a hazard ratio of 1.79 (95% CI: 1.42–2.27, P < 0.001) and 73.6% in class III (4–6 points) with a hazard ratio of 2.24 (95% CI: 1.64–3.06, P < 0.001). Conclusions: Based on this retrospective analysis within a large patient population from a multicenter study, the GREAT score shows good external validity and can be used for assessing the risk for relapse in Graves’ disease, which infuence the initial treatment decisions. Introduction Graves’ disease (GD) is the most frequent cause of primary hyperthyroidism with an approximate prevalence of 0.5% (1, 2). In Europe and Asia, standard treatment for Graves’ disease includes use of antithyroid drugs (ATD) for a recommended duration of 12–18 months (3). This approach offers the possibility of disease resolution www.eje-online.org © 2017 European Society of Endocrinology 176:4 413–419 T Struja, M Kaeslin, F Boesiger and others External validation of GREAT score European Journal of Endocrinology (2017) 176, 413–419 Clinical Study Correspondence should be addressed to T Struja Email tristan.struja@gmail.com Downloaded from Bioscientifica.com at 06/02/2020 04:50:00PM via Massachusetts Inst of Technology