title: The effects of patient function and dependence on costs of care in Alzheimer's disease.
abstract: OBJECTIVE
  To estimate incremental effects of patients' dependence and function on costs of care during the early stages of Alzheimer's disease (AD) and to compare strengths of their relationships with different cost components.
  
  
  METHODS
  Multicenter, cross-sectional, observational study.
  
  
  METHODS
  Three university hospitals in the United States.
  
  
  METHODS
  One hundred seventy-nine community-living patients with probable AD, with modified Mini-Mental State Examination scores of 30 or higher.
  
  
  METHODS
  Patients' dependence was measured using the Dependence Scale (DS). Functional capacity was measured using the Blessed Dementia Rating Scale (BDRS). Total cost was measured by summing direct medical costs and informal costs. Direct medical costs included costs of hospitalization, outpatient treatment and procedures, assistive devices, and medications. Informal costs were estimated from time spent helping with basic and instrumental activities of daily living for up to three caregivers per patient using national average hourly earnings as wage rate.
  
  
  RESULTS
  DS and BDRS were associated with higher total cost; a 1-point increase in DS was associated with a $1,832 increase in total cost, and a 1-point increase in BDRS was associated with a $3,333 increase. Examining component costs separately identified potential differences between DS and BDRS. A 1-point increase in BDRS was associated with a $1,406 increase in direct medical cost. A 1-point increase in DS was associated with a $1,690 increase in informal cost.
  
  
  CONCLUSIONS
  Patients' dependence and function related differently to direct medical and informal cost, suggesting that measures of function and dependence provided unique information for explaining variations in cost of care for patients with AD, highlighting the value in measuring both constructs.
authors.affiliation: Geriatric Research, Education, and Clinical Center, Program of Research on Serious Physical and Mental Illness, James J Peters Veterans Affairs Medical Center, Bronx, New York 10468, USA. carolyn.zhu@mssm.edu
authors.forename: Carolyn W
authors.initials: CW
authors.lastname: Zhu
authors.forename: Christopher
authors.initials: C
authors.lastname: Leibman
authors.forename: Trent
authors.initials: T
authors.lastname: McLaughlin
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Scarmeas
authors.forename: Marilyn
authors.initials: M
authors.lastname: Albert
authors.forename: Jason
authors.initials: J
authors.lastname: Brandt
authors.forename: Deborah
authors.initials: D
authors.lastname: Blacker
authors.forename: Mary
authors.initials: M
authors.lastname: Sano
authors.forename: Yaakov
authors.initials: Y
authors.lastname: Stern
mesh_terms: D000203:Activities of Daily Living / Q000145:classification*; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000191:economics*; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005260:Female; D015577:Geriatric Assessment / Q000706:statistics & numerical data; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D014481:United States