Prevalence and correlates of dementia: survey of the last days of life.

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.