title: Mapping CushingQOL scores to EQ-5D utility values using data from the European Registry on Cushing's syndrome (ERCUSYN).
abstract: OBJECTIVE
  To construct a model to predict preference-adjusted EuroQol 5D (EQ-5D) health utilities for CS using the disease-specific health-related quality of life measure (CushingQOL).
  
  
  METHODS
  Data were obtained from the European Registry on CS (ERCUSYN). ERCUSYN is a web-based, multicenter, observational study that enrolled 508 CS patients from 36 centers in 23 European countries. Patients included in the study completed both the EQ-5D and the disease-specific CushingQOL questionnaire. Socio-demographic and clinical data were also collected. The UK tariff values were used to calculate EQ-5D utility scores. Various predictive models were tested, and the final model was selected based on four criteria: explanatory power (adjusted R-squared), consistency of estimated coefficients (sign and parameter estimation), normality of prediction errors (mean error, mean absolute error, root mean squared error), and parsimony.
  
  
  RESULTS
  For the mapping analysis, data were available from a total of 129 patients. Mean (SD) age was 43.1 (13) years, and the sample was predominantly female (84.5 %). Patients had a mean (SD) CushingQOL score of 39.7 (17.1) and a mean (SD) 'tariff' value on the EQ-5D of 0.55 (0.3). The model which best met the criteria for selection included the intercept and 3 CushingQOL's questions and had an R(2) of 0.506 and a root mean square error of 0.216.
  
  
  CONCLUSIONS
  It was possible to find a mapping function which successfully predicted the EQ-5D UK utilities from disease-specific CushingQOL scores. The function may be useful in calculating EQ-5D scores when EQ-5D data have not been gathered directly in a study.
authors.affiliation: Health Economics and Outcomes Research, IMS Health, C/ Dr. Ferran 25-27, 2º, 08034, Barcelona, Spain.
authors.forename: X
authors.initials: X
authors.lastname: Badia
authors.forename: M
authors.initials: M
authors.lastname: Roset
authors.forename: E
authors.initials: E
authors.lastname: Valassi
authors.forename: H
authors.initials: H
authors.lastname: Franz
authors.forename: A
authors.initials: A
authors.lastname: Forsythe
authors.forename: S M
authors.initials: SM
authors.lastname: Webb
mesh_terms: D000328:Adult; D000368:Aged; D003480:Cushing Syndrome / Q000523:psychology / Q000628:therapy*; D005060:Europe; D005260:Female; D006296:Health Services / Q000706:statistics & numerical data; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D057240:Patient Preference; D011594:Psychometrics; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D012042:Registries; D012044:Regression Analysis; D011795:Surveys and Questionnaires
references.citation: Eur J Health Econ. 2010 Apr;11(2):215-25
references.pmid: 19585162
references.citation: Value Health. 2007 Sep-Oct;10(5):408-14
references.pmid: 17888106
references.citation: Med Decis Making. 2001 Mar-Apr;21(2):105-12
references.pmid: 11310943
references.citation: Value Health. 2007 Mar-Apr;10(2):153-60
references.pmid: 17391424
references.citation: Pharmacoeconomics. 1995 Jun;7(6):490-502
references.pmid: 10155335
references.citation: J Clin Epidemiol. 1998 Nov;51(11):1115-28
references.pmid: 9817129
references.citation: Ann Surg. 2007 May;245(5):790-4
references.pmid: 17457173
references.citation: J Health Econ. 2002 Mar;21(2):271-92
references.pmid: 11939242
references.citation: Health Qual Life Outcomes. 2011 Apr 18;9:26
references.pmid: 21501522
references.citation: Med Care. 1997 Nov;35(11):1095-108
references.pmid: 9366889
references.citation: Value Health. 2011 Sep-Oct;14(6):884-91
references.pmid: 21914510
references.citation: Med Decis Making. 2006 Jan-Feb;26(1):18-29
references.pmid: 16495197
references.citation: Eur J Endocrinol. 2011 Oct;165(4):527-35
references.pmid: 21798958
references.citation: Eur J Endocrinol. 2011 Sep;165(3):383-92
references.pmid: 21715416
references.citation: Neuroendocrinology. 2010;92 Suppl 1:1-5
references.pmid: 20829610
references.citation: Eur J Endocrinol. 2008 May;158(5):623-30
references.pmid: 18426820
references.citation: J Clin Endocrinol Metab. 2003 Dec;88(12):5593-602
references.pmid: 14671138
references.citation: Clin Endocrinol (Oxf). 2008 Nov;69(5):775-84
references.pmid: 18462264
references.citation: Endocrinol Metab Clin North Am. 1994 Sep;23(3):607-17
references.pmid: 7805657
references.citation: Med Decis Making. 2004 May-Jun;24(3):247-54
references.pmid: 15185716
references.citation: Ann Med. 2001 Jul;33(5):337-43
references.pmid: 11491192
references.citation: Rev Endocr Metab Disord. 2010 Jun;11(2):95-104
references.pmid: 19960264
references.citation: Med Decis Making. 2001 Jan-Feb;21(1):7-16
references.pmid: 11206949
references.citation: Med Care. 2004 Sep;42(9):927-37
references.pmid: 15319619
references.citation: Surgery. 2002 Dec;132(6):1064-8; discussion 1068-9
references.pmid: 12490856
references.citation: Eur J Heart Fail. 2005 Mar 2;7(2):243-51
references.pmid: 15701474
references.citation: Stat Med. 1998 Jul 30;17(14):1623-34
references.pmid: 9699234
references.citation: J Clin Endocrinol Metab. 2005 Jun;90(6):3279-86
references.pmid: 15741267