title: Cognitive function and acute care utilization.
abstract: OBJECTIVE
  Little is known about variation in cognitive function across the aged population, or how use and costs of health care vary with cognitive impairment. This study was designed to create a typology of cognitive function in a nationally representative sample, and evaluate acute care use in relation to cognitive function, holding constant confounding factors. By including proxy assessments of cognitive function, this is the first study to include individuals unable to respond themselves.
  
  
  METHODS
  We analyzed the baseline year of the Asset and Health Dynamics Among the Oldest Old (AHEAD) survey, sponsored by the National Institute on Aging, to create three levels of cognitive function, using direct measures for self-respondents (n = 6,651) and proxy evaluations for the others (n = 792). We used a two-part model to predict the likelihood of using various health services and to evaluate intensity of care among users.
  
  
  RESULTS
  Sixteen percent, 64%, and 20% of the sample fell into the low, moderate, and high cognitive function groups, respectively, that differed significantly on almost all demographic and health status measures, and some utilization measures. Controlling for other health and functional status measures, lower cognitive function had a significant and negative effect on outpatient services, but did not affect hospital use directly.
  
  
  CONCLUSIONS
  Lower cognitive function may be a barrier to outpatient care, but these analyses should be repeated using administrative use and cost data.
authors.affiliation: Center for Health Economics Research, Waltham, Massachusetts, USA. ewalsh@rti.org
authors.forename: Edith G
authors.initials: EG
authors.lastname: Walsh
authors.forename: Bei
authors.initials: B
authors.lastname: Wu
authors.forename: Janet B
authors.initials: JB
authors.lastname: Mitchell
authors.forename: Lisa F
authors.initials: LF
authors.lastname: Berkmann
mesh_terms: D000368:Aged; D003072:Cognition Disorders / Q000145:classification* / Q000175:diagnosis; D005260:Female; D015577:Geriatric Assessment; D015438:Health Behavior; D006304:Health Status; D006760:Hospitalization / Q000706:statistics & numerical data*; D006761:Hospitals / Q000706:statistics & numerical data; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D009483:Neuropsychological Tests; D010044:Outpatient Clinics, Hospital / Q000706:statistics & numerical data; D012720:Severity of Illness Index; D014481:United States