Objectives: To estimate the prevalence and correlates of dementia at death and to assess the usefulness of death certificate data in the reporting of dementia.
Methods: The authors analyzed next-of-kin interviews for 599 male and 628 female decedents using data from the National Institute on Aging's Survey of the Last Days of Life.
Results: Death certificate data in this population show the prevalence of dementia to be less than 1%, consistent with previous reports based on death certificates but a substantial underestimate compared to the 11.9% reported in a national survey. Using a dementia index based on the informant's report of whether the decedent had been diagnosed with a dementing illness and the extent of her or his cognitive and functional limitations, this study found a prevalence of dementia of 8.5%. A high score on the dementia index was significantly associated with older age, Parkinson's disease, and incontinence. Lower relative odds for dementia at death were found for people with either a lifetime history or a death certificate report of cancer. Similarly, people with a lifetime history of coronary heart disease were found to have lower relative odds for dementia at death.
Conclusion: These results suggest that informant interviews may be a useful source of data to examine factors associated with dementia and to estimate the prevalence of dementia in the last year of life.