title: New medical diagnoses and length of stay of acutely unwell older patients: Implications for funding models.
abstract: OBJECTIVE
  To examine the relationship between newly made medical diagnoses and length of stay (LOS) of acutely unwell older patients.
  
  
  METHODS
  Consecutive patients admitted under the care of four geriatricians were randomly allocated to a model development sample (n = 937) or a model validation sample (n = 855). Cox regression was used to model LOS. Variables considered for inclusion in the development model were established risk factors for LOS and univariate predictors from our dataset. Variables selected in the development sample were tested in the validation sample.
  
  
  RESULTS
  A median of five new medical diagnoses were made during a median LOS of 10 days. New diagnoses predicted an increased LOS (hazard ratio 0.90, 95% confidence interval 0.88-0.92). Other significant predictors of increased LOS in both samples were malnutrition and frailty.
  
  
  CONCLUSIONS
  Identification of new medical diagnoses may have implications for Diagnosis Related Groups-based funding models and may improve the care of older people.
authors.affiliation: Liverpool Hospital, Sydney, New South Wales, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Basic
authors.affiliation: Liverpool Hospital, Sydney, New South Wales, Australia.
authors.forename: Angela
authors.initials: A
authors.lastname: Khoo
mesh_terms: D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D001315:Australia; D003953:Diagnosis-Related Groups; D005260:Female; D006304:Health Status; D006801:Humans; D007902:Length of Stay; D008297:Male; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models
keywords: aged; diagnosis; diagnosis related group; economics; length of stay