title: Associations between drug burden index and mortality in older people in residential aged care facilities.
abstract: BACKGROUND
  The Drug Burden Index (DBI), a measure of an individual's exposure to anticholinergic and sedative medications, is associated with functional impairment in community-dwelling, older people. In people from residential aged care facilities (RACFs), DBI score does not appear to be associated with functional impairment, but is associated with an increased risk of falls.
  
  
  OBJECTIVE
  We investigated the associations between increasing DBI score and mortality in older adults living in RACFs.
  
  
  METHODS
  Study participants (n = 602; 70.9% female), recruited from 51 RACFs in Sydney, Australia, had a mean ± standard deviation (SD) age of 85.7 ± 6.4 years and a mean ± SD DBI score of 0.58 ± 0.64.
  
  
  RESULTS
  Exposure to anticholinergic medication was 33.6% and sedative medications 41.9%. All-cause mortality after a variable follow-up time (774-1269 days) was 36.2% (n = 218), with the leading causes of death classified as stroke (n = 46; 21.1%), ischaemic heart disease/cardiovascular system (n = 44; 20.2%) and pneumonia (n = 31; 14.2%). One-year mortality multivariate models showed that the DBI categories low (n = 260; hazard ratio [HR] 1.13; 95% CI 0.82, 1.57) and high (n = 153; HR 1.19; 95% CI 0.82, 1.74) were not associated with mortality. This lack of a significant association remained after dichotomization into the anticholinergic and sedative components of the DBI.
  
  
  CONCLUSIONS
  We found that with high exposure to anticholinergic and sedative medications, there was no significant association between increasing DBI score and all-cause mortality in old individuals living in RACFs. Further research into the adverse effects of medication use on the mortality of institutionalized older individuals is needed.
authors.affiliation: Kolling Institute of Medical Research, Institute of Bone and Joint Research, Royal North Shore Hospital, Sydney, NSW, Australia.
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Wilson
authors.forename: Sarah N
authors.initials: SN
authors.lastname: Hilmer
authors.forename: Lyn M
authors.initials: LM
authors.lastname: March
authors.forename: Jian Sheng
authors.initials: JS
authors.lastname: Chen
authors.forename: Danijela
authors.initials: D
authors.lastname: Gnjidic
authors.forename: Rebecca S
authors.initials: RS
authors.lastname: Mason
authors.forename: Ian D
authors.initials: ID
authors.lastname: Cameron
authors.forename: Philip N
authors.initials: PN
authors.lastname: Sambrook
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D018680:Cholinergic Antagonists; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives; D008297:Male; D009026:Mortality; D015999:Multivariate Analysis; D012112:Residential Facilities / Q000706:statistics & numerical data*
chemical_list: D018680:Cholinergic Antagonists; D006993:Hypnotics and Sedatives