title: From KIDSCREEN-10 to CHU9D: creating a unique mapping algorithm for application in economic evaluation.
abstract: BACKGROUND
  The KIDSCREEN-10 index and the Child Health Utility 9D (CHU9D) are two recently developed generic instruments for the measurement of health-related quality of life in children and adolescents. Whilst the CHU9D is a preference based instrument developed specifically for application in cost-utility analyses, the KIDSCREEN-10 is not currently suitable for application in this context. This paper provides an algorithm for mapping the KIDSCREEN-10 index onto the CHU9D utility scores.
  
  
  METHODS
  A sample of 590 Australian adolescents (aged 11-17) completed both the KIDSCREEN-10 and the CHU9D. Several econometric models were estimated, including ordinary least squares estimator, censored least absolute deviations estimator, robust MM-estimator and generalised linear model, using a range of explanatory variables with KIDSCREEN-10 items scores as key predictors. The predictive performance of each model was judged using mean absolute error (MAE) and root mean squared error (RMSE).
  
  
  RESULTS
  The MM-estimator with stepwise-selected KIDSCREEN-10 items scores as explanatory variables had the best predictive accuracy using MAE, whilst the equivalent ordinary least squares model had the best predictive accuracy using RMSE.
  
  
  CONCLUSIONS
  The preferred mapping algorithm (i.e. the MM-estimate with stepwise selected KIDSCREEN-10 item scores as the predictors) can be used to predict CHU9D utility from KIDSCREEN-10 index with a high degree of accuracy. The algorithm may be usefully applied within cost-utility analyses to generate cost per quality adjusted life year estimates where KIDSCREEN-10 data only are available.
authors.affiliation: Flinders Health Economics Group, School of Medicine, Flinders University, Adelaide, Australia. gang.chen@flinders.edu.au.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
authors.forename: Katherine
authors.initials: K
authors.lastname: Stevens
authors.forename: Donna
authors.initials: D
authors.lastname: Rowen
authors.forename: Julie
authors.initials: J
authors.lastname: Ratcliffe
mesh_terms: D000293:Adolescent; D000465:Algorithms; D001315:Australia; D002648:Child; D002669:Child Welfare / Q000191:economics*; D017281:Cost of Illness; D003362:Cost-Benefit Analysis; D005260:Female; D006305:Health Status Indicators; D006306:Health Surveys; D006801:Humans; D016014:Linear Models; D008297:Male; D018803:Models, Economic; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D015203:Reproducibility of Results; D057566:Self Report