title: Predictors of costs of care in Alzheimer's disease: a multinational sample of 1222 patients.
abstract: BACKGROUND
  The costs of care for patients with Alzheimer's disease are correlated with key measures of disease severity. This relationship is important in the economic evaluation of new treatments and is used to translate treatment efficacy into effects on costs through economic modeling. We aimed to identify what measures of disease severity are the most important predictors of societal costs of care and whether their relationship differs across countries.
  
  
  METHODS
  Interviews were conducted with 1222 patient and caregiver pairs residing in the community or in residential care settings in Spain, Sweden, United Kingdom, and the United States. Assessments included costs of care (Resource Utilization in Dementia) and key disease severity measures: cognitive function (Mini-Mental State Examination), ability to perform Activities of Daily Living (ADL-ability, Disability Assessment for Dementia [DAD]), and behavioral symptoms (Neuropsychiatry Inventory (NPI)-severity).
  
  
  RESULTS
  ADL-ability was the most important predictor of societal costs of care of community-dwelling patients in all countries. A one-point decrease in DAD resulted in a 1.4% increase in costs of care in Spain, United Kingdom, and the United States on average, and a 2% increase in Sweden. This translated into a 45% increase from a standard deviation decrease in DAD on average. NPI-severity and Mini-Mental State Examination were also significant predictors but with lesser effect. Although mean costs of care differed across countries, the important predictors were the same.
  
  
  CONCLUSIONS
  ADL-ability is the most important predictor of societal costs of care in community dwellings irrespective of country and should therefore be central in the economic evaluation of Alzheimer's disease therapies.
authors.affiliation: Alzheimer's Disease Research Center, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Sweden. anders.gustavsson@ki.se
authors.forename: Anders
authors.initials: A
authors.lastname: Gustavsson
authors.forename: Per
authors.initials: P
authors.lastname: Brinck
authors.forename: Niklas
authors.initials: N
authors.lastname: Bergvall
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Kolasa
authors.forename: Anders
authors.initials: A
authors.lastname: Wimo
authors.forename: Bengt
authors.initials: B
authors.lastname: Winblad
authors.forename: Linus
authors.initials: L
authors.lastname: Jönsson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000191:economics* / Q000453:epidemiology / Q000628:therapy*; D040561:Assisted Living Facilities / Q000191:economics / Q000639:trends; D005260:Female; D014943:Global Health; D017048:Health Care Costs / Q000639:trends*; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D013030:Spain / Q000453:epidemiology; D013548:Sweden / Q000453:epidemiology; D006113:United Kingdom / Q000453:epidemiology; D014481:United States / Q000453:epidemiology