title: Using EQ-5D to derive general population-based utilities for the quality of life assessment of growth hormone deficiency in adults (QoL-AGHDA).
abstract: OBJECTIVE
  Disease-oriented quality of life (QoL) measures that are not preference-based lack legitimacy for direct use in cost-utility analyses. This has prompted the search for other methods for deriving utilities. The QoL Assessment of Growth Hormone Deficiency in Adults questionnaire (QoL-AGHDA) is a disease-oriented measure used to assess impairment in QoL in adults with growth hormone deficiency. The present study was designed to generate a model for deriving utilities from the QoL-AGHDA.
  
  
  METHODS
  The EQ-5D, the QoL-AGHDA, and demographic questions were mailed to a random sample (n = 3005) of the Swedish population (response rate 65%). Multiple regression analysis was used to obtain cross-validated parameters of QoL-AGHDA-based utilities. Two models were developed (simple and full versions). The simple version used the EQ-5D(index) (derived from European values) as the dependent variable, and age, sex, and QoL-AGHDA score as independent variables in a regression analysis. The full model utilized all available demographic information. The QoL-AGHDA scores were thus transformed into a single score (0-1), corresponding to the QoL-AGHDA-based utility.
  
  
  RESULTS
  The simple transformation algorithm was U (QoL-AGHDA-based utilities) = 1.05 - 0.0189 x QoL-AGHDA score - 0.00238 x age - 0.0127 x sex (male = 0; female = 1). The mean of the weighted estimate for the population (n = 1752) was 0.85 (SD 0.10). The estimate for men (n = 861; mean 0.86; SD 0.10) was higher (P < 0.001) than for women (n = 891; mean 0.84; SD 0.10).
  
  
  CONCLUSIONS
  For practical reasons, the simple model can be recommended for deriving utilities directly from the QoL-AGHDA for the Swedish population.
authors.affiliation: KIGS/KIMS/ACROSTUDY Medical Outcomes, Pfizer Endocrine Care, Pfizer Health AB, Sollentuna, Sweden. maria.koltowska-haggstrom@pfizer.com
authors.forename: Maria
authors.initials: M
authors.lastname: Kołtowska-Häggström
authors.forename: Björn
authors.initials: B
authors.lastname: Jonsson
authors.forename: Dag
authors.initials: D
authors.lastname: Isacson
authors.forename: Kerstin
authors.initials: K
authors.lastname: Bingefors
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D013006:Growth Hormone / Q000172:deficiency*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010900:Pituitary Diseases / Q000503:physiopathology* / Q000523:psychology; D011594:Psychometrics / Q000295:instrumentation*; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D013548:Sweden
chemical_list: D013006:Growth Hormone