title: [What does the average stay say about the diagnosis-related groups?].
abstract: BACKGROUND
  The systems for classifying patients into homogeneous groups of resource consumption such as diagnosis related groups (DRG) use mean stay (MS) as the principal predictive variable of this consumer entity. The standard of MS for each DRG is usually defined as the MS of this DRG in one group of hospitals. This method omits the existence of unnecessary days of hospitalization which are added to the standard and may be identified by review of hospitalary use.
  
  
  METHODS
  A retrospective review of the clinical need for 933 days of hospitalization (190 days of admission plus 743 successive stays for the same) in 190 cases of 167 DRG (appendicectomy without complications or comorbidity in those under the age of 70 years) in 8 public hospitals in Valencia (Spain) was performed by the Appropriateness Use Evaluation Protocol.
  
  
  RESULTS
  Four days of admission (2.1%) and 284 successive stays (38.2%) were considered unnecessary from a clinical point of view. Necessary MS was estimated as 3.4 days for GRD vs the 5.1 days of MS observed.
  
  
  CONCLUSIONS
  The common construction of standards of mean stay per disease demonstrates an important proportion of unnecessary use of hospitalization, the correction of which would allow a reduction in the mean costs of the process without a reduction in the quality of care.
authors.affiliation: Institut Valencià d'Estudis en Salut Pública (IVESP), Valencia.
authors.forename: S
authors.initials: S
authors.lastname: Peiró
authors.forename: R
authors.initials: R
authors.lastname: Meneu de Guillerna
authors.forename: M L
authors.initials: ML
authors.lastname: Roselló Pérez
authors.forename: E
authors.initials: E
authors.lastname: Martínez
authors.forename: E
authors.initials: E
authors.lastname: Portella
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001062:Appendectomy; D002648:Child; D003953:Diagnosis-Related Groups / Q000706:statistics & numerical data*; D005260:Female; D017408:Guidelines as Topic; D006300:Health Services Misuse / Q000706:statistics & numerical data; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
vernacular_title: Qué mide la estancia media de los grupos relacionados de diagnóstico?