title: Predictors of rapid cognitive decline in Alzheimer's disease: results from the Australian imaging, biomarkers and lifestyle (AIBL) study of ageing.
abstract: BACKGROUND
  The AIBL study, which commenced in November 2006, is a two-center prospective study of a cohort of 1112 volunteers aged 60+. The cohort includes 211 patients meeting NINCDS-ADRDA criteria for Alzheimer's disease (AD) (180 probable and 31 possible). We aimed to identify factors associated with rapid cognitive decline over 18 months in this cohort of AD patients.
  
  
  METHODS
  We defined rapid cognitive decline as a drop of 6 points or more on the Mini-Mental State Examination (MMSE) between baseline and 18-month follow-up. Analyses were also conducted with a threshold of 4, 5, 7 and 8 points, as well as with and without subjects who had died or were too severely affected to be interviewed at 18 months and after, both including and excluding subjects whose AD diagnosis was "possible" AD. We sought correlations between rapid cognitive decline and demographic, clinical and biological variables.
  
  
  RESULTS
  Of the 211 AD patients recruited at baseline, we had available data for 156 (73.9%) patients at 18 months. Fifty-one patients were considered rapid cognitive decliners (32.7%). A higher Clinical Dementia Rating scale (CDR) and higher CDR "sum of boxes" score at baseline were the major predictors of rapid cognitive decline in this population. Furthermore, using logistic regression model analysis, patients treated with a cholinesterase inhibitor (CheI) had a higher risk of being rapid cognitive decliners, as did males and those of younger age.
  
  
  CONCLUSIONS
  Almost one third of patients satisfying established research criteria for AD experienced rapid cognitive decline. Worse baseline functional and cognitive status and treatment with a CheI were the major factors associated with rapid cognitive decline over 18 months in this population.
authors.affiliation: AOU San Giovanni Battista - Molinette, Geriatria e Malattie Metaboliche dell'Osso, Università degli Studi di Torino, Torino, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Sona
authors.forename: Ping
authors.initials: P
authors.lastname: Zhang
authors.forename: David
authors.initials: D
authors.lastname: Ames
authors.forename: Ashley I
authors.initials: AI
authors.lastname: Bush
authors.forename: Nicola T
authors.initials: NT
authors.lastname: Lautenschlager
authors.forename: Ralph N
authors.initials: RN
authors.lastname: Martins
authors.forename: Colin L
authors.initials: CL
authors.lastname: Masters
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Rowe
authors.forename: Cassandra
authors.initials: C
authors.lastname: Szoeke
authors.forename: Kevin
authors.initials: K
authors.lastname: Taddei
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Ellis
mesh_terms: D000544:Alzheimer Disease / Q000139:chemically induced / Q000175:diagnosis* / Q000523:psychology; D001315:Australia; D002800:Cholinesterase Inhibitors / Q000009:adverse effects; D003071:Cognition / Q000187:drug effects; D018450:Disease Progression; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D009483:Neuropsychological Tests; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors
chemical_list: D002800:Cholinesterase Inhibitors