Survival in dementia and predictors of mortality: a review

OBJECTIVE: Dementia is an important cause of mortality and, with the ageing population and increasing prevalence of dementia, reliable data on prognosis and survival will be of interest to patients and caregivers as well as providers and commissioners of health and social care. A review of the literature was undertaken to determine the rates of survival in dementia and Alzheimer's disease (AD) and to identify factors that are or are not predictive of mortality in dementia and AD. METHODS: Relevant articles on mortality in dementia were identified following a search of several electronic databases from 1990 to September 2012. Inclusion criteria were reports on prospective community or clinic based cohorts published in English since 1990, to reflect more recent recognition of possible predictors. RESULTS: Median survival time from age of onset of dementia ranges from 3.3 to 11.7 years, with most studies in the 7 to 10-year period. Median survival time from age of disease diagnosis ranges from 3.2 to 6.6 years for dementia or AD cohorts as a whole. Age was consistently reported as a predictor of mortality, with male gender a less consistent predictor. Increased disease severity and functional impairment were often associated with mortality. CONCLUSIONS: Substantial heterogeneity in the design of included studies limits the ability to prognosticate for individual patients. However, it is clear that dementia and AD are associated with significant mortality. Reasons for the increased mortality are not established.