title: Environmental factors predict the severity of delirium symptoms in long-term care residents with and without delirium.
abstract: OBJECTIVE
  To identify potentially modifiable environmental factors (including number of medications) associated with changes over time in the severity of delirium symptoms and to explore the interactions between these factors and resident baseline vulnerability.
  
  
  METHODS
  Prospective, observational cohort study.
  
  
  METHODS
  Seven long-term care (LTC) facilities.
  
  
  METHODS
  Two hundred seventy-two LTC residents aged 65 and older with and without delirium.
  
  
  METHODS
  Weekly assessments (for up to 6 months) of the severity of delirium symptoms using the Delirium Index (DI), environmental risk factors, and number of medications. Baseline vulnerability measures included a diagnosis of dementia and a delirium risk score. Associations between environmental factors, medications, and weekly changes in DI were analyzed using a general linear model with correlated errors.
  
  
  RESULTS
  Six potentially modifiable environmental factors predicted weekly changes in DI (absence of reading glasses, aids to orientation, family member, and glass of water and presence of bed rails and other restraints) as did the prescription of two or more new medications. Residents with dementia appeared to be more sensitive to the effects of these factors.
  
  
  CONCLUSIONS
  Six environmental factors and prescription of two or more new medications predicted changes in the severity of delirium symptoms. These risk factors are potentially modifiable through improved LTC clinical practices.
authors.affiliation: St. Mary's Research Centre, St. Mary's Hospital, Montreal, Quebec, Canada. jane.mccusker@mcgill.ca
authors.forename: Jane
authors.initials: J
authors.lastname: McCusker
authors.forename: Martin G
authors.initials: MG
authors.lastname: Cole
authors.forename: Philippe
authors.initials: P
authors.lastname: Voyer
authors.forename: Minh
authors.initials: M
authors.lastname: Vu
authors.forename: Antonio
authors.initials: A
authors.lastname: Ciampi
authors.forename: Johanne
authors.initials: J
authors.lastname: Monette
authors.forename: Nathalie
authors.initials: N
authors.lastname: Champoux
authors.forename: Eric
authors.initials: E
authors.lastname: Belzile
authors.forename: Alina
authors.initials: A
authors.lastname: Dyachenko
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D002170:Canada; D015331:Cohort Studies; D003221:Confusion / Q000453:epidemiology*; D003693:Delirium / Q000453:epidemiology*; D005260:Female; D006304:Health Status; D006801:Humans; D008134:Long-Term Care; D008297:Male; D008603:Mental Health / Q000706:statistics & numerical data*; D011446:Prospective Studies; D012112:Residential Facilities / Q000458:organization & administration*; D012307:Risk Factors; D012720:Severity of Illness Index; D012931:Social Environment