title: Underuse of diagnostic codes for specific dementias in the Veterans Affairs New England healthcare system.
abstract: OBJECTIVE
  To examine the specificity of dementia coding in large populations.
  
  
  METHODS
  Retrospective cohort and chart review study of dementia diagnosis.
  
  
  METHODS
  U.S. Department of Veterans Affairs (VA) New England healthcare system.
  
  
  METHODS
  Veterans aged 50 and older given outpatient visit codes for dementia between January 1, 2000, and December 31, 2009.
  
  
  METHODS
  The frequency of the code "dementia not otherwise specified (DNOS)" as a first and final diagnosis was determined. DNOS use was examined according to provider type and geographic location. The medical records of 100 individuals with unspecified dementia were reviewed to determine their underlying diagnoses and describe their examination.
  
  
  RESULTS
  Twenty-two thousand fifty veterans diagnosed with dementia were identified over 10 years of follow-up. One-third of all cases had no specific dementia code (n = 6,659). DNOS was the most commonly used code as a first dementia diagnosis (42.5%) and was second only to Alzheimer's type dementia (35.8%) as a final diagnosis. Individuals who saw geriatricians and neurologists were most likely to have a specific dementia diagnosis, and DNOS use was lowest in centers with the most dementia specialists. Only 12% of primary care physicians performed cognitive testing the first time they used the DNOS code, compared with 98% of specialists. Nearly half of individuals with a persistent diagnosis of DNOS met criteria for a specific dementia.
  
  
  CONCLUSIONS
  Substantial overuse was found of nonspecific dementia codes in the VA New England healthcare system, leading to an underestimation of the prevalence of Alzheimer's disease and other dementias. System-based changes in dementia coding and greater access to dementia specialists may help improve diagnostic specificity.
authors.affiliation: College of Medicine, University of Arizona, Tucson, Arizona, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Butler
authors.forename: Neil W
authors.initials: NW
authors.lastname: Kowall
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Lawler
authors.forename: J
authors.initials: J
authors.lastname: Michael Gaziano
authors.forename: Jane A
authors.initials: JA
authors.lastname: Driver
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis; D059019:Clinical Coding / Q000706:statistics & numerical data*; D015331:Cohort Studies; D003704:Dementia / Q000175:diagnosis*; D006801:Humans; D008875:Middle Aged; D009511:New England; D012189:Retrospective Studies; D014481:United States; D014493:United States Department of Veterans Affairs