title: Quality of life and relative importance: a comparison of time trade-off and conjoint analysis methods in patients with age-related macular degeneration.
abstract: OBJECTIVE
  To investigate the relative priorities in quality of life (QoL) in patients with age-related macular degeneration (AMD).
  
  
  METHODS
  Measures of visual function, QoL and utility associated with visual loss were obtained from 122 patients with AMD classified according to macular morphology. The two methods of utility assessment were time trade-off (TTO) and conjoint analysis (CA), which have been recommended by the UK's National Institute of Clinical Excellence as techniques for the assessment of healthcare priorities.
  
  
  RESULTS
  Results show that the two methods for assessing utility are poorly related: TTO relates moderately to visual function and disease severity but CA does not. CA identified two different subgroups of patients: one with outdoor mobility and the other with reading as their main priority.
  
  
  CONCLUSIONS
  Further work is needed and caution required in interpreting data obtained using these methodologies for determining their relative importance in vision-related QoL studies.
authors.affiliation: Heriot-Watt University, Riccarton, Edinburgh EH14 3AZ, Scotland, UK. p.a.aspinall@sbe.hw.ac.uk
authors.forename: P A
authors.initials: PA
authors.lastname: Aspinall
authors.forename: A R
authors.initials: AR
authors.lastname: Hill
authors.forename: B
authors.initials: B
authors.lastname: Dhillon
authors.forename: A M
authors.initials: AM
authors.lastname: Armbrecht
authors.forename: P
authors.initials: P
authors.lastname: Nelson
authors.forename: C
authors.initials: C
authors.lastname: Lumsden
authors.forename: E
authors.initials: E
authors.lastname: Farini-Hudson
authors.forename: R
authors.initials: R
authors.lastname: Brice
authors.forename: A
authors.initials: A
authors.lastname: Vickers
authors.forename: P
authors.initials: P
authors.lastname: Buchholz
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D002755:Choice Behavior; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008268:Macular Degeneration / Q000523:psychology / Q000534:rehabilitation*; D008297:Male; D011788:Quality of Life; D012720:Severity of Illness Index; D015348:Vision, Binocular; D014792:Visual Acuity