title: Effectiveness of antidementia drugs in delaying Alzheimer's disease progression.
abstract: BACKGROUND
  Randomized controlled trials (RCTs) provide safety and efficacy data for regulatory approval of antidementia drugs, but offer limited data regarding real-world effectiveness. Long-term observational controlled studies (LTOCs) extend our understanding by providing longitudinal data across multiple stages of Alzheimer's disease (AD).
  
  
  METHODS
  Comparisons of strengths, limitations, evidence level, and results for monotherapy (cholinesterase inhibitors) and combination therapy (cholinesterase inhibitors + memantine) in RCTs versus LTOCs were made.
  
  
  RESULTS
  Similar to RCTs, LTOCs have shown that both monotherapy and combination therapy are associated with slower cognitive and functional decline. Combination therapy is associated with better cognitive outcomes and greater delays in time to nursing home admission versus monotherapy or no treatment. Persistent antidementia drug treatment is associated with slower decline in cognition, daily function, and global severity, even in patients with advanced disease.
  
  
  CONCLUSIONS
  LTOCs provide complementary evidence regarding effectiveness of antidementia therapy over many years, a time course relevant to AD management. These findings also provide compelling arguments in favor of using LTOCs to estimate effectiveness, risk-benefit, and costs of AD treatments.
authors.affiliation: Department of Neurology, Alzheimer's Disease and Memory Disorders Center, Baylor College of Medicine, Houston, TX, USA. rountree@bcm.edu
authors.forename: Susan D
authors.initials: SD
authors.lastname: Rountree
authors.forename: Alireza
authors.initials: A
authors.lastname: Atri
authors.forename: Oscar L
authors.initials: OL
authors.lastname: Lopez
authors.forename: Rachelle S
authors.initials: RS
authors.lastname: Doody
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000188:drug therapy* / Q000453:epidemiology; D002800:Cholinesterase Inhibitors / Q000627:therapeutic use; D003704:Dementia / Q000188:drug therapy* / Q000453:epidemiology; D000077265:Donepezil; D015259:Dopamine Agents / Q000627:therapeutic use; D019317:Evidence-Based Medicine; D006801:Humans; D007189:Indans / Q000627:therapeutic use; D008559:Memantine / Q000627:therapeutic use; D018697:Nootropic Agents / Q000627:therapeutic use*; D010880:Piperidines / Q000627:therapeutic use; D015995:Prevalence; D016032:Randomized Controlled Trials as Topic
chemical_list: D002800:Cholinesterase Inhibitors; D015259:Dopamine Agents; D007189:Indans; D018697:Nootropic Agents; D010880:Piperidines; D000077265:Donepezil; D008559:Memantine