The effects of patient function and dependence on costs of care in Alzheimer's disease.
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.
Zhu
Carolyn W
CW
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
Leibman
Christopher
C
McLaughlin
Trent
T
Scarmeas
Nikolaos
N
Albert
Marilyn
M
Brandt
Jason
J
Blacker
Deborah
D
Sano
Mary
M
Stern
Yaakov
Y
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