What is Alzheimer life expectancy?
Enter the age when dementia began and sex to see how long half of a matching group lived in a large population study, with the range for the middle half. For information only. This is not medical advice or a diagnosis. Do not use it to make treatment decisions without a clinician. No licensed clinician has reviewed this page.
- Median survival
- 5.4 years
For women and men, onset at 70 to 79, the median survival in the study was 5.4 years; the middle half lived 3.4 to 8.3 years.
- Middle half lived
- 3.4 to 8.3 years
- Study group
- women and men, onset at 70 to 79
Median survival: 5.4 years. For women and men, onset at 70 to 79, the median survival in the study was 5.4 years; the middle half lived 3.4 to 8.3 years.
This calculator gives general information only. It is not medical advice and does not replace a doctor or other health care provider. Talk with a professional about your results. Terms of use
How to calculate
Looks up the median survival after dementia begins, by age at onset and sex, from a large population study in England and Wales (Xie 2008), with the range in which the middle half of people lived.
Example with the default inputs (Age when dementia began 75, Sex Both): For women and men, onset at 70 to 79, the median survival in the study was 5.4 years; the middle half lived 3.4 to 8.3 years.
Method: A table lookup, with no model: the row of Xie 2008, Table 2 for the age group at onset (65 to 69, 70 to 79, 80 to 89, 90 or more) and sex (women, men, or all).
- From 438 people over 65 who developed dementia in the MRC Cognitive Function and Ageing Study, England and Wales, 1991 to 2005.
- Onset is the midpoint between the last follow-up without dementia and the first with it. The study counts all dementia, not only Alzheimer’s disease.
- A median describes a group. It does not predict how long one person will live.
Worked examples
Each example is checked against the calculator on every build.
- Age when dementia began 75, Sex Both gives Median survival 5.4 years, Middle half lived 3.4 to 8.3 years, Study group women and men, onset at 70 to 79.Source: Xie 2008, Table 2: onset at 70 to 79, all, median 5.4 (IQR 3.4 to 8.3)
- Age when dementia began 85, Sex Female gives Median survival 4.4 years, Middle half lived 2.8 to 7.0 years.Source: Xie 2008, Table 2: onset at 80 to 89, women, median 4.4 (IQR 2.8 to 7.0)
- Age when dementia began 92, Sex Male gives Median survival 3.4 years, Middle half lived 1.5 to 5.5 years.Source: Xie 2008, Table 2: onset at 90 or more, men, median 3.4 (IQR 1.5 to 5.5)
- Age when dementia began 67, Sex Male gives Median survival Not reached in the study, Middle half lived 9.1 years or more (upper quartile not reached).Source: Xie 2008, Table 2: onset at 65 to 69, men, median NA (lower quartile 9.1, upper NA)
- Age when dementia began 69, Sex Female gives Median survival 7.5 years, Middle half lived 4.8 years or more (upper quartile not reached), Study group women, onset at 65 to 69.Source: Xie 2008, Table 2: onset at 65 to 69, women, median 7.5 (IQR 4.8 to NA)
Medical disclaimer
This calculator is for information and education only. It is not medical advice, and its result is not a diagnosis. Do not use it to start, stop, or change a treatment without a clinician who knows your health history. No licensed clinician has reviewed this page. This site's editors checked the formulas and worked examples against published sources. If you think you have a medical emergency, call your local emergency number.
When this does not apply. The figures come from 438 people aged 65 or more in England and Wales who developed dementia during the study (1991 to 2003, deaths followed to 2005). They do not apply to dementia that begins before 65, and they may differ in other countries and with newer care.
How it is looked up
There is no formula. The page reads one row of Xie 2008, Table 2: median survival in years from onset, and the interquartile range, by age at onset and sex.
| Age at onset | Women | Men | All |
|---|---|---|---|
| 65 to 69 | 7.5 (4.8 to NA) | NA (9.1 to NA) | 10.7 (5.6 to NA) |
| 70 to 79 | 5.8 (3.6 to 8.3) | 4.6 (3.0 to 8.6) | 5.4 (3.4 to 8.3) |
| 80 to 89 | 4.4 (2.8 to 7.0) | 3.7 (2.5 to 6.3) | 4.3 (2.8 to 7.0) |
| 90 or more | 3.9 (2.4 to 5.2) | 3.4 (1.5 to 5.5) | 3.8 (2.3 to 5.2) |
- Age group: 65 to 69, 70 to 79, 80 to 89, or 90 or more, by the whole years typed (65 to 110).
- Sex "Both" reads the "All" column.
- NA means the study could not give a value, because too few people in the group had died. A missing median shows as "Not reached in the study"; a missing upper quartile shows the range as "lower quartile or more (upper quartile not reached)".
- Onset is the midpoint between the last follow-up without dementia and the first with it.
- Values show with 1 decimal, as printed.
Worked examples by hand
Onset at 75, both sexes. Row 70 to 79, All: 5.4 years; middle half 3.4 to 8.3 years.
Woman, onset at 85. Row 80 to 89, Women: 4.4 years; 2.8 to 7.0 years.
Man, onset at 92. Row 90 or more, Men: 3.4 years; 1.5 to 5.5 years.
Man, onset at 67. Row 65 to 69, Men: median NA, not reached; range 9.1 years or more (upper quartile not reached).
Woman, onset at 69. Row 65 to 69, Women: 7.5 years; 4.8 years or more (upper quartile not reached).
Other questions people ask
What is the life expectancy after an Alzheimer's diagnosis?
It depends most on age. In the study this page uses (Xie 2008), half of the people whose dementia began at 70 to 79 lived 5.4 years or more, and half of those whose dementia began at 90 or later lived 3.8 years or more. Brookmeyer (2002) found a median of 8.3 years for Alzheimer’s disease diagnosed at 65 and 3.4 years at 90.
Do women live longer with dementia than men?
In Xie 2008 the median was 4.6 years for women and 4.1 years for men overall. Larson (2004) found 5.7 years for women and 4.2 years for men after a diagnosis of Alzheimer’s disease.
Why does the page talk about dementia and not only Alzheimer’s?
The study with an open table by age and sex counted all dementia, of which Alzheimer’s disease is the most common type. Studies of Alzheimer’s alone give similar figures, but their tables by age are not open to readers.
What does "not reached" mean?
For men whose dementia began at 65 to 69, fewer than half had died by the end of the study, so no median could be given. A quarter of them died within 9.1 years.
What is the "middle half" range?
The interquartile range: a quarter of the group died before its low end and a quarter lived past its high end.
Can this predict how long one person will live?
No. A median describes a group. Health, how advanced the dementia is, falls, and other illnesses change the outlook for one person a great deal.