Alzheimer's live about half as long as those of similar age without dementia

Age, seriousness of impairment, and the severity of other medical conditions are important indicators of how long an individual might survive after an Alzheimer's disease diagnosis, Eric B. Larson, M.D., M.P.H. and colleagues report in the April 6 Annals of Internal Medicine. Study authors include Linda Teri, Ph.D., recipient of an Alzheimer's Association $1 million Pioneer research grant.

Overall, Larson's group found that individuals newly diagnosed with Alzheimer's tended to live about half as long as those of similar age without dementia. For example, following an Alzheimer diagnosis, a 70-year-old woman's life expectancy dropped from 15.7 to 8 years, and a 70-year-old man's fell from 9.3 to 4.4 years. By age 85, Alzheimer's cut expected survival from 5.9 years to 3.9 years for women and from 4.7 years to 3.3 years for men.

In the 521 individuals enrolled in this study, the characteristics associated with the lowest survival times were age greater than 85 years, difficulty walking, history of wandering, and the presence of diabetes or congestive heart failure. Other characteristics that shortened survival were male sex, greater degree of cognitive impairment, involuntary release of urine, and a history of falls, diabetes, coronary artery disease or stroke.

Factors not shown to decrease survival here included high blood pressure, the duration of symptoms at the time of diagnosis, or the presence of depression, irritability, paranoia or other behavioral or psychiatric symptoms.

In an editorial also appearing in the April 6 Annals of Internal Medicine, Kevin E. Covinsky, M.D., M.P.H., and Kristine Yaffe, M.D., point out that, "…patients receiving a diagnosis of dementia have substantially decreased life expectancies…Clinicians may be alert to the palliative care needs of patients with metastatic cancer but may not realize that a dementia diagnosis is also a sentinel event for planning end-of-life care…Many patients with dementia are not able to obtain the palliative services they need, such as assistance with activities of daily living, day health services, and respite care. As a result, caregivers shoulder most of the burden of caring for a patient with dementia."