title: Providing an extended use of an otological-specific outcome instrument to derive cost-effectiveness estimates of treatment.
abstract: OBJECTIVE
  Although quality-adjusted life years (QALYs) are increasingly being used by decision-makers to make comparisons of cost-effectiveness, there are no otological-specific outcome measures that fit within this QALY framework. This study had two main objectives. The first was to provide a means to derive QALYs from a condition-specific otological instrument (Cambridge Otology Quality of Life, COQOL), and the second was to assess the convergent validity, or degree of correlation, between the COQOL and SF-6D, an established QALY instrument.
  
  
  METHODS
  Longitudinal cohort study designed to assess the convergent validity between SF-6D and COQOL and to generate a mapping function to enable SF-6D values to be predicted from the COQOL responses.
  
  
  METHODS
  Cambridge University Hospital, UK.
  
  
  METHODS
  A total of 207 patients attending a routine outpatient general otology clinic.
  
  
  METHODS
  SF-6D and the COQOL instrument completed at baseline and again 3 months later.
  
  
  RESULTS
  Convergent validity was demonstrated with mean SF-6D values decreasing linearly with increasing severity on the COQOL instrument. Overall, the correlation between the COQOL scores and the SF-6D values was moderate and statistically significant (r = 0.490, P = <0.001). A simple mapping model based on an ordinary least squares (OLS) regression function predicted SF-6D values from the COQOL data with a reasonable degree of accuracy. Further validation using the follow-up 3-month data confirmed the prediction power of this mapping model.
  
  
  CONCLUSIONS
  This study provides a method for estimating QALYs from condition-specific COQOL data and provides the opportunity for the cost-effectiveness of otological treatment to be measured and placed within the national QALY framework.
authors: Health Economics Unit, School of Health and Population Sciences, University of Birmingham, Birmingham, UK.
authors: E J
authors: EJ
authors: Frew
authors: Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada.|Centre for Health Evaluation and Outcome Sciences, St Paul's Hospital, Vancouver, BC, Canada.
authors: M
authors: M
authors: Harrison
authors: Health Economics Unit, School of Health and Population Sciences, University of Birmingham, Birmingham, UK.
authors: M
authors: M
authors: Rossello Roig
authors: ENT Department, Worcester Royal Hospital, Worcester, UK.
authors: T P C
authors: TP
authors: Martin
mesh_terms: D017281:Cost of Illness; D003362:Cost-Benefit Analysis; D003657:Decision Making; D004427:Ear Diseases / Q000191:economics / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010036:Otolaryngology / Q000191:economics* / Q000379:methods; D011594:Psychometrics / Q000191:economics*; D011788:Quality of Life; D011795:Surveys and Questionnaires; D013997:Time Factors; D006113:United Kingdom