title: Predictive models to estimate utility from clinical questionnaires in schizophrenia: findings from EuroSC.
abstract: OBJECTIVE
  The clinical symptoms of schizophrenia are associated with serious social, quality of life and functioning alterations. Typically, data on health utilities are not available in clinical studies in schizophrenia. This makes the economic evaluation of schizophrenia treatments challenging. The purpose of this article was to provide a mapping function to predict unobserved utility values in patients with schizophrenia from the available clinical and socio-demographic information.
  
  
  METHODS
  The analysis was performed using data from EuroSC, a 2-year, multi-centre, cohort study conducted in France (N = 288), Germany (N = 618), and the UK (N = 302), totalling 1208 patients. Utility was calculated based on the EQ-5D questionnaire. The relationships between the utility values and the patients' socio-demographic and clinical characteristics (Positive and Negative Syndrome Scale--PANSS, Calgary Depression Scale for Schizophrenia--CDSS, Global Assessment of Functioning--GAF, extra-pyramidal symptoms measured by Barnes Akathisia Scale-BAS, age, sex, country, antipsychotic type) were modelled using a random and a fixed individual effects panel linear model.
  
  
  RESULTS
  The analysis demonstrated the prediction ability of the used parameters for estimating utility measures in patients with schizophrenia. Although there are small variations between countries, the same variables appear to be the key predictors. From a clinical perspective, age, gender, psychopathology, and depression were the most important predictors associated with the EQ-5D.
  
  
  CONCLUSIONS
  This paper proposed a reliable, robust and easy-to-apply mapping method to estimate EQ-5D utilities based on demographic and clinical measures in schizophrenia.
authors.affiliation: Research Laboratory in Knowledge Engineering (ERIC, EA3083), Institute of Pharmaceutical and Biological Sciences (ISPB), University Claude Bernard Lyon 1, 11 Rue Guillaume Paradin, 69372, Lyon Cedex 08, France. carole.siani@univ-lyon1.fr.
authors.forename: Carole
authors.initials: C
authors.lastname: Siani
authors.affiliation: Laboratory of Actuarial and Financial Sciences (SAF, EA2429), Institute of Financial and Insurance Sciences (ISFA School), University Claude Bernard Lyon 1, 50 Avenue Tony Garnier, 69366, Lyon Cedex 7, France.
authors.forename: Christian
authors.initials: C
authors.lastname: de Peretti
authors.affiliation: Creativ-Ceutical, 215 Rue du Faubourg Saint Honoré, 75008, Paris, France. ami@creativ-ceutical.com.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Millier
authors.affiliation: Laboratory of Public Health (EA 3279), Faculty of Medicine, Aix-Marseille University, 27 bd Jean Moulin, 13385, Marseille Cedex 05, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Boyer
authors.affiliation: Aix-Marseille University, 27 bd Jean Moulin, 13385, Marseille Cedex 05, France.
authors.forename: Mondher
authors.initials: M
authors.lastname: Toumi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D015331:Cohort Studies; D003863:Depression / Q000175:diagnosis*; D003866:Depressive Disorder / Q000175:diagnosis*; D005260:Female; D005602:France; D005858:Germany; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D011788:Quality of Life / Q000523:psychology*; D012559:Schizophrenia / Q000188:drug therapy*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D006113:United Kingdom; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents
keywords: Mapping; Positive and Negative Syndrome Scale; Quality of life; Schizophrenia