Dementia time to death: a systematic literature review on survival time and years of life lost in people with dementia

Background: Life expectancy with dementia directly influences rates of prevalence and service needs and is a common question posed by families and patients. As well as years of survival, it is useful to consider years of life lost after a diagnosis of dementia. Methods: We systematically reviewed the literature on mortality and survival with dementia which were compared to estimated life expectancies in the general population. Both were then compared by age (under 65 years vs. 65+ years), gender, dementia type, severity, and two epochs (prior to and after introduction of cholinesterase inhibitors in 1997). Results: Survival after a diagnosis of dementia varies considerably and depends on numerous factors and their complex interaction. Relative loss of life expectancy decreases with age at diagnosis across varying gender, dementia subtypes (except for frontotemporal dementia and dementia with Lewy bodies), and severity stages. Numerous study deficiencies precluded a meta-analysis of survival in dementia. Conclusion: Estimates of years of life lost through dementia may be helpful for patients and their families. Recommendations for future research methods are proposed.