Life Expectancy Calculator for Alzheimer’s Disease & Dementia

The Short Answer to a Big Question

After being diagnosed with dementia, most people ask: How long do I have left to live? The answer depends on the dementia. Someone Alzheimer’s disease, the most common form of dementia, is expected to live for about 10 years after the diagnosis. For patients with Huntington’s disease or Lewy body dementia, the answers are different, as the table below shows. In fact, the answers change depending on a variety of factors, which is why we’ve developed a Life Expectancy Calculator, which you can use now by clicking here. Keep reading to learn more about life expectancy in dementia patients, why it’s important, what affects it and how it changes by stage.

Below are the average life expectancies for the most common types of dementia:

Keep in mind that everyone with dementia experiences its impacts and symptoms differently. People have lived more than 25 years after being diagnosed with Alzheimer’s disease. Mitigating factors include gender, overall health and the severity of early symptoms.

Why Knowing Life Expectancy is Useful

Calculating the life expectancy of a loved one can be sad and deeply emotional, and it may feel cold. However, knowing what to expect is beneficial in a number of important ways. It will impact budgeting, estate planning and scheduling events. Knowing how quickly the dementia is expected to progress can significantly influence care decisions, including where an individual will live, from assisted living residences to memory care communities or nursing homes.

If a move into a memory care facility or nursing home seems like it will be necessary, knowing in advance will give families time to make financial plans for the move. That will include applying for Medicaid for many families: it’s estimated that 50% of nursing home residents have some level of dementia and over 60% of nursing home residents’ care is paid for by Medicaid. But it might take years for a loved one to become Medicaid eligible, and it takes time to apply for Medicaid, and even after an application is accepted some seniors end up on a waitlist before receiving benefits. So, understanding life expectancy and knowing when care might be required can prove financially beneficial for the dementia patient and their family.

Evidence that Life Expectancy Calculators for Dementia Actually Work

A 2014 Columbia University study proved it is possible to accurately predict life expectancy and other key healthcare moments for people with people dementia. The study followed more than 500 Alzheimer’s disease patients for a 10-year period. During that time, researchers predicted when the patients, who started with mild symptoms, would need full-time care, when they would need to move into an institution like a memory care facility or a nursing home, and when they would die. Their predictions were 95% accurate.

The predictions in the Columbia study were based on semiannual assessments of the Alzheimer’s patients. There were evaluated for:

• Cognitive abilities
• Motor skills
• Overall health
• Awareness of self, place and time
• Behavior
• Emotional stability

The results from these assessments, as well as scores from the Mini-Mental State Exam, were then plugged into an algorithm that would calculate the predictions for life expectancy and the need for long-term care.

These results are backed up by a 2012 University of Kentucky study that analyzed the records of more than 1,200 people with dementia and found that it was possible to predict their life expectancy accurately. Researchers looked at multiple variables, including family history and medical problems like high blood pressure and heart disease. In the end, the study showed life expectancy came down to three factors: gender, age when the first symptoms appeared and the strength of symptoms when first diagnosed, which are detailed below.

To be clear, these models are only predictors. There is no way to pinpoint the moment someone will die. But it is possible to see patterns in groups of dementia patients that can help individuals and families in similar situations plan for the future.

Variables Impacting Life Expectancy Calculations

• Gender – Men don’t live as long with Alzheimer’s as women. A University of Washington study conducted between 1987 and 1996 with more than 500 people diagnosed with Alzheimer’s disease found that women with Alzheimer’s live, on average, 20% longer than men.
• Age at diagnosis – Someone diagnosed at 65 lives an average of about eight years, while someone over 90 who gets a diagnosis typically lives about three-and-a-half more years.
• Strength of symptoms at diagnosis – If someone is showing especially severe dementia-related problems at the time of diagnosis (wandering, falling, incontinence), their life expectancy is typically shorter than someone who only shows mild symptoms (forgetfulness, mild mood swings) at diagnosis.
• Other health problems – A person with any significant health issues like diabetes, heart problems or asthma, for example, will probably not live as long as someone without those underlying issues.

Life Expectancy by Stage of the Disease

As mentioned, people with Alzheimer’s disease will live for about 10 years after their initial diagnosis. However, it’s important to keep in mind that there’s a gap between when dementia symptoms begin and when they are diagnosed. The first symptoms of Alzheimer’s disease —forgetting names, misplacing items, difficulty performing simple tasks — usually arrive two to three years before a diagnosis is made.

The scale most health professionals use to differentiate the stages of dementia is the Global Deterioration Scale (GDS). , which is also known as the Reisberg Scale. The table below shows a patient’s average life expectancy in the context of the GDS stages of dementia. These figures are based on studies done with large numbers of Alzheimer’s patients.

People with early onset or young-onset dementia live for about the same number of years, 10, after diagnosis as those with more common forms of dementia. About 5% of cases of Alzheimer’s disease are young-onset, meaning symptoms develop between the ages of 30 and 60.

Do Treatments Add Time to Life Expectancy?

Experts do not know whether treatments will help people with dementia live longer. Alzheimer’s and other dementias are progressive diseases, meaning they continually worsen. Some medications and therapies have been conclusively shown to help manage dementia symptoms, making it easier to live with the disease, but they do not eliminate the disease or reverse its course.