title: Predicting time trade-off health state valuations of adolescents in four Pacific countries using the Assessment of Quality-of-Life (AQoL-6D) instrument.
abstract: OBJECTIVE
  Pacific Obesity Prevention in Communities (OPIC) is a community-based intervention project targeting adolescent obesity in Australia, New Zealand, Fiji, and Tonga. The Assessment of Quality of Life Mark 2 (AQoL-6D) instrument was completed by 15,481 adolescents to obtain a description of the quality of life associated with adolescent overweight and obesity, and a corresponding utility score for use in a cost-utility analysis of the interventions. This article describes the recalibration of this utility instrument for adolescents in each country.
  
  
  METHODS
  The recalibration was based on country-specific time trade-off (TTO) data for 30 multiattribute health states constructed from the AQoL-6D descriptive system. Senior secondary students, in a classroom setting, responded to 10 health state scenarios each. These TTO interviews were conducted for 24 groups, comprising 279 students in the four countries resulting in 2790 completed TTO scores. The TTO scores were econometrically transformed by regressing the TTO scores upon predicted scores from the AQoL-6D to produce country-specific algorithms. The latter incorporated country-specific "corrections" to the Australian adult utility weights in the original AQoL.
  
  
  RESULTS
  This article reports two methodological elements not previously reported. The first is the econometric modification of an extant multi-attribute utility instrument to accommodate cultural and other group-specific differences in preferences. The second is the use of the TTO technique with adolescents in a classroom group setting. Significant differences in utility scores were found between the four countries.
  
  
  CONCLUSIONS
  Statistical results indicate that the AQoL-6D can be validly used in the economic evaluation of both the OPIC interventions and other adolescent programs.
authors.affiliation: Deakin Health Economics, Population Health Strategic Research Centre, Deakin University, Melbourne, Australia. marj.moodie@deakin.edu.au
authors.forename: Marj
authors.initials: M
authors.lastname: Moodie
authors.forename: Jeff
authors.initials: J
authors.lastname: Richardson
authors.forename: Bree
authors.initials: B
authors.lastname: Rankin
authors.forename: Angelo
authors.initials: A
authors.lastname: Iezzi
authors.forename: Kompal
authors.initials: K
authors.lastname: Sinha
mesh_terms: D000293:Adolescent; D001294:Attitude to Health / Q000208:ethnology*; D001315:Australia; D054521:Cultural Competency; D005260:Female; D005367:Fiji; D006801:Humans; D008297:Male; D009520:New Zealand; D009765:Obesity; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D011795:Surveys and Questionnaires; D014058:Tonga