title: Predicting the short form-6D preference-based index using the eight mean short form-36 health dimension scores: estimating preference-based health-related utilities when patient level data are not available.
abstract: OBJECTIVE
  The objective is to derive an algorithm to predict a cohort preference-based short form-6D (short form-6D) score using the eight mean health dimension scores from the short form-36 (SF-36) when patient level data are not available.
  
  
  METHODS
  Health-related quality of life data (N = 6890) covering a wide range of health conditions was used to explore the relationship between the SF-6D and the eight health dimension scores. Models obtained using ordinary least square regressions were compared for goodness of fit and predictive abilities on both within-sample subgroups and out-of-sample published data sets.
  
  
  RESULTS
  The models explained more than 83% of the variance in the individual SF-6D scores with a mean absolute error of 0.040. When using mean health dimension scores from within-sample subgroups and out-of-sample published data sets, the majority of predicted scores were well within the minimal important difference (0.041) for the SF-6D.
  
  
  CONCLUSIONS
  This article presents a mechanism to estimate a mean cohort preference-based SF-6D score using the eight mean health dimension scores of the SF-36. Using published summary statistics, the out-of-sample validation demonstrates that the algorithms can be used to inform both clinical and economic research. Further research is required in different health conditions.
authors.affiliation: Health Economics & Decision Science, The University of Sheffield, Sheffield, Yorkshire, UK. r.m.ara@sheffield.ac.uk
authors.forename: Roberta
authors.initials: R
authors.lastname: Ara
authors.forename: John
authors.initials: J
authors.lastname: Brazier
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D015331:Cohort Studies; D005260:Female; D005544:Forecasting; D006305:Health Status Indicators; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D015999:Multivariate Analysis; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D012044:Regression Analysis; D012720:Severity of Illness Index; D018434:Sickness Impact Profile; D013223:Statistics as Topic; D011795:Surveys and Questionnaires; D055815:Young Adult