Registered Nurses' Association of Ontario

Nursing Best Practice Guidelines

Background – Facts and Statistics about Delirium, Dementia, & Depression


  • Adversely affects function and outcomes and is associated with high morbidity and mortality.
  • It is an acute, complex disorder that requires immediate interventions to prevent permanent brain damage and health risks, including death.
  • It is “associated with mortality rates of 25-33 %, and results in increased length of hospital stay, increased intensity of nursing care, more institutional placements, and greater healthcare costs” (Inouye, 2000, p. 257).


  • The key features of dementia include multiple cognitive deficits which are severe enough to cause impairment in an individual’s social or occupational functioning, and represent a decline from a previous level of functioning (APA, 1997).
  • These cognitive deficits include memory impairment and at least one of the following:
    or a decline in executive functioning.
  • The prevalence of dementia increases with age and ranges from a low of 8 % for individuals aged 65 years to 35 % for those aged 85 years and older (Canadian Study of Health and Aging Working Group, 1994).


  • A multi-faceted syndrome, comprised of a constellation of affective, cognitive, somatic and physiological manifestations, in varying degrees from mild to severe (Kurlowicz & NICHE Faculty, 1997; National Advisory Committee on Health and Disability, 1996; National Institute of Health Consensus Development Panel, 1992).
  • Depressive symptoms occur in 10 to 15 % of community-based elderly requiring clinical attention.
  • Mortality and morbidity rates increase in the elderly experiencing depression, and there is a high incidence of co-morbidity with medical conditions (Conwell, 1994).