title: Informal Care Time and Cost in a Large Clinical Trial Sample of Patients with Mild to Moderate Alzheimer's Disease: Determinants and Level of Change Observed.
abstract: BACKGROUND
  We evaluate the association between caregiver (informal) time/cost and illness severity from two recently completed clinical trials of an investigational drug for Alzheimer's disease (AD).
  
  
  METHODS
  Changes from baseline caregiver time were calculated and treatment effects analyzed using a restricted maximum likelihood-based mixed model for repeated measures. Four separate models were then estimated to examine the association between caregiver time costs and the clinical endpoints measured during the trials, including cognition (MMSE), function (DAD), behavior (NPI), global disability (CDR) and dependence (DS).
  
  
  RESULTS
  Caregiver time cost was significantly associated with all clinical measures of illness severity with a 1-unit change in MMSE, DAD, NPI, CDR and DS associated with a 11.57%, 4.81-4.97%, 3.58-3.67%, 42.52% and 71.05% change, respectively, in primary caregiver time cost. The association between caregiver time cost and DS was the strongest of all the associations examined.
  
  
  CONCLUSIONS
  Caregiver time costs increase with increasing AD severity in all key domains of AD (cognition, function, behavior, global disability and dependence on others). Our analysis demonstrated that patient dependence is a particularly important predictor of caregiver time costs and should be considered as a potential outcome measure in intervention clinical trials in AD.
  
  
  BACKGROUND
  Pfizer Inc. and Janssen Alzheimer Immunotherapy Research and Development.
authors.affiliation: Lacey Solutions, Ltd., The Beaches, South Strand, Skerries, Dublin, Ireland.
authors.forename: Loretto
authors.initials: L
authors.lastname: Lacey
authors.affiliation: Pfizer Inc., 500 Arcola Road, Collegeville, PA, 19426, USA. joel.bobula@pfizer.com.
authors.forename: Joel
authors.initials: J
authors.lastname: Bobula
authors.affiliation: Niecko Health Economics, LLC, 275 Indies Way, Naples, FL, 34110, USA.
authors.forename: Timothy
authors.initials: T
authors.lastname: Niecko
authors.affiliation: Biogen, Zählerweg 6, 6300, Zug, Switzerland.
authors.forename: Christopher
authors.initials: C
authors.lastname: Leibman
keywords: Alzheimer’s disease; Informal caregiver; Time and costs