February 5, 2025
Wondering how long a family member with Alzheimer’s disease might live is a fraught concern for many families. The difficulties are often compounded by questions about whether a loved one should enter a nursing home.
While no one can reliably predict how long an individual with Alzheimer’s disease will live or when they may require nursing home care, a new analysis provides additional information about an Alzheimer’s prognosis. It found that the average survival time varied widely according to age at diagnosis and the sex of the patient, ranging from two to nine years, though many people with Alzheimer’s live much longer. The findings could help families better prepare for long-term care.
“Age at diagnosis is the most important determinant of prognosis in people with dementia,” the authors write. “Women lived slightly longer with dementia than men, which was due in large part to older age at diagnosis.”
For women diagnosed at age 60, the average life expectancy was 8.9 years, compared to about eight years after a diagnosis at age 65, and four-and-a-half years at age 85. For men, average survival ranged from six-and-a-half years at age 60, 5.7 years at age 65, and 2.2 years at age 85.
The study also found that about a third of people with dementia are admitted to a nursing home within three years of receiving a diagnosis. About 13 percent of people were admitted in the first year after diagnosis, increasing to 35 percent at three years and 57 percent at five years. On average, most people spent the last third of their life after a dementia diagnosis in a nursing home.
For the study, published in the British medical journal BMJ, researchers in the Netherlands reviewed 261 studies on dementia survival and nursing home admissions published between 1984 and 2024. The studies involved more than five million men and women whose average age was 79 at follow-up. Most of the studies were conducted in Europe and North America, with an average follow-up time of seven years.
Overall, the researchers calculated that a dementia diagnosis at age 65 reduced life expectancy by about 13 years. A diagnosis at age 80 reduced life expectancy by three to four years, on average, while a diagnosis at age 85 reduced survival time by about two years.
Average life expectancy was 1.4 years longer for those with Alzheimer’s disease compared to other forms of dementia. “Patients with Alzheimer’s disease had a more favorable prognosis than those with vascular dementia, frontotemporal dementia, or Lewy body dementia,” the authors note.
These are observational findings and only represent averages across a large patient population. Any single patient may live much longer, or shorter, than a peer, depending on any number of factors. For example, having coexisting medical conditions can have a strong influence on life expectancy. Certain treatments for Alzheimer’s, like the use of some antipsychotic drugs, have also been shown to shorten lifespan.
On the other hand, people with Alzheimer’s disease can take steps to improve survival. For example, one recent study found that people with dementia who performed any intensity of exercise, whether gentle walking or a hard-core cycling class several days a week, lowered the risk of dying early by 20 percent or more. Other studies suggest that eating a Mediterranean-style diet, rich in fruits, vegetables and whole grains, is associated with a lower mortality from Alzheimer’s disease.
In an accompanying editorial, researchers in Norway note that more study is needed to better understand the long-term course of Alzheimer’s disease. “Discussing remaining life expectancy and time to death is a delicate matter” for doctors, they write. “But it is even more challenging to provide information about the timeline for dependency and need for nursing home care because many factors are involved, not only the type of dementia, sex, and age of patients, but also comorbidities, lifestyle, and socioeconomic and cultural factors.”
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, Ph.D. Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Chiara C. Bruck; Sanne S. Mooldjik, Lieke M. Kuiper, et al : Time to nursing home admission and death in people with dementia: systematic review and meta-analysis. BMJ January 8, 2025
Bjorn Heine Stand, Anette Hylen Ranhoff: Dementia, survival rates, and nursing home admissions (editorial). BMJ January 8, 2025
