title: New model to explain the EQ-5D VAS in patients who have undergone spinal fusion.
abstract: BACKGROUND
  In the health sector, the EQ-5D has been widely used to evaluate health-related quality of life, mainly due to its simplicity, robustness and plasticity in calculating years of life adjusted for quality.
  
  
  METHODS
  However, its model has remained stable over time and knowledge of the influence of such biodemographical variables as age and gender has not been incorporated. This information, along with the well-known non-linear behavior of the VAS, which measures the self-concept of the 'General State of Health', forms the basis for a new model, which we present here from a sample of patients who were operated on for chronic low back pain.
  
  
  RESULTS
  These are obtained using multiple regression analysis are consistent in terms of goodness-of-fit given that this new model is able to explain 91.3% of the self-concept of the 'general state of health'.
  
  
  CONCLUSIONS
  Above leads to an improvement of 21.6% compared to the available models more robust and meets most of the restrictions for this type of statistical modeling.
authors.affiliation: Departamento de Matemática y Estadística, Facultad de Ingeniería, Ciencias y Administración, Universidad De La Frontera, Mailbox 54-D, Temuco, Chile. jcortes@ufro.cl
authors.forename: Jorge
authors.initials: J
authors.lastname: Cortés
authors.forename: Juan F
authors.initials: JF
authors.lastname: Blanco
authors.forename: David
authors.initials: D
authors.lastname: Pescador
authors.forename: Nuria
authors.initials: N
authors.lastname: Asensio
authors.forename: Claudio
authors.initials: C
authors.lastname: Castro
authors.forename: Juan Moncada
authors.initials: JM
authors.lastname: Herrera
mesh_terms: D000328:Adult; D000368:Aged; D002908:Chronic Disease; D005260:Female; D006304:Health Status; D006801:Humans; D017116:Low Back Pain / Q000523:psychology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D010147:Pain Measurement / Q000592:standards* / Q000706:statistics & numerical data; D011594:Psychometrics / Q000379:methods*; D011788:Quality of Life; D012044:Regression Analysis; D018434:Sickness Impact Profile; D013030:Spain; D013123:Spinal Fusion; D011795:Surveys and Questionnaires / Q000592:standards; D055815:Young Adult