title: External validation of the GREAT score to predict relapse risk in Graves' disease: results from a multicenter, retrospective study with 741 patients.
abstract: BACKGROUND
  First-line treatment in Graves' disease is often done with antithyroid agents (ATD), but relapse rates remain high making definite 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.
  
  
  METHODS
  We retrospectively analyzed data (2004-2014) of patients with a first episode of Graves' hyperthyroidism from four Swiss endocrine outpatient clinics.
  
  
  METHODS
  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 T4, 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 influence the initial treatment decisions.
authors.affiliation: Medical University DepartmentClinic for Endocrinology, Diabetes & Metabolism.
authors.forename: Tristan
authors.initials: T
authors.lastname: Struja
authors.affiliation: Medical University DepartmentClinic for Endocrinology, Diabetes & Metabolism.
authors.forename: Marina
authors.initials: M
authors.lastname: Kaeslin
authors.affiliation: Medical University DepartmentClinic for Endocrinology, Diabetes & Metabolism.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Boesiger
authors.affiliation: Medical University DepartmentClinic for Endocrinology, Diabetes & Metabolism.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Jutzi
authors.affiliation: Medical University DepartmentClinic for Endocrinology, Diabetes & Metabolism.
authors.forename: Noemi
authors.initials: N
authors.lastname: Imahorn
authors.affiliation: Medical University DepartmentClinic for Endocrinology, Diabetes & Metabolism.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kutz
authors.affiliation: Department of Laboratory MedicineKantonsspital Aarau, Aarau, Switzerland.
authors.forename: Luca
authors.initials: L
authors.lastname: Bernasconi
authors.affiliation: Department of Laboratory MedicineKantonsspital Aarau, Aarau, Switzerland.
authors.forename: Esther
authors.initials: E
authors.lastname: Mundwiler
authors.affiliation: Medical University DepartmentClinic for Endocrinology, Diabetes & Metabolism.|Medical Faculty of the University of BaselBasel, Switzerland.
authors.forename: Beat
authors.initials: B
authors.lastname: Mueller
authors.affiliation: Medical Faculty of the University of BaselBasel, Switzerland.|Clinic for EndocrinologyDiabetes & Metabolism, University Hospital of Basel, Basel, Switzerland.
authors.forename: Mirjam
authors.initials: M
authors.lastname: Christ-Crain
authors.affiliation: Clinic for EndocrinologyDiabetes & Metabolism, University Hospital of Basel, Basel, Switzerland.
authors.forename: Fabian
authors.initials: F
authors.lastname: Meienberg
authors.affiliation: Clinic for EndocrinologyDiabetes & Metabolism, University Hospital of Basel, Basel, Switzerland.
authors.forename: Fahim
authors.initials: F
authors.lastname: Ebrahimi
authors.affiliation: Medical Faculty of the University of BaselBasel, Switzerland.|Clinic for EndocrinologyDiabetes & Metabolism, Kantonsspital Luzern, Luzern, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Henzen
authors.affiliation: Clinic for EndocrinologyDiabetes & Metabolism, Kantonsspital Luzern, Luzern, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Fischli
authors.affiliation: Medical Faculty of the University of BaselBasel, Switzerland.|Clinic for EndocrinologyDiabetes & Metabolism, University Hospital of Basel, Basel, Switzerland.
authors.forename: Marius
authors.initials: M
authors.lastname: Kraenzlin
authors.affiliation: Medical Faculty of the University of BaselBasel, Switzerland.|Clinic for EndocrinologyDiabetes & Metabolism, University Hospital of Basel, Basel, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Meier
authors.affiliation: Medical University DepartmentClinic for Endocrinology, Diabetes & Metabolism.|Medical Faculty of the University of BaselBasel, Switzerland.
authors.forename: Philipp
authors.initials: P
authors.lastname: Schuetz
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006111:Graves Disease / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D006980:Hyperthyroidism / Q000473:pathology; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D012008:Recurrence; D012189:Retrospective Studies