This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
Researchers have developed the first reliable test for dementia in people with hearing loss. The test is an adapted version of a standard test for dementia. It is accurate in people with and without hearing loss.
Hearing loss commonly occurs alongside dementia, yet tests for dementia often include verbal questions that rely on hearing. The new test replaces spoken questions with written ones. It was evaluated in a study of 256 people and found to be accurate and reliable. People scored similarly when they were tested 2 to 4 weeks after their first test.
The new test could accurately diagnose dementia in people with hearing problems. However, it needs to be explored further. Women tended to score lower than men, and it was less effective in different languages.
More information about cognitive assessment can be found on the NHS website.
What’s the issue?
More than 3 in 4 people aged over 75 years have hearing problems. Many people with dementia therefore also have hearing loss. But many standard tests for assessing memory, attention and language include spoken questions and rely on good hearing. People with hearing loss score worse in these tests, which could lead to a false diagnosis of dementia.
The Montreal Cognitive Assessment (MoCA) is commonly used to diagnose cognitive impairment or dementia. Other researchers have tried removing spoken questions from this test to accommodate hearing loss. However, this approach made the test less accurate.
In this study, the team replaced spoken questions with written questions.
What’s new?
Researchers removed 3 spoken questions (one assessing attention and two assessing language) from the MoCA test. They tested several alternative written questions, and replaced the spoken questions with those that performed best.
The next part of the study included 256 people aged 60 years or more from 7 sites in England, Ireland and Australia. 159 people had hearing loss and took the revised test only; 83 of this group were known to have dementia. The remaining 97 people (with no hearing problems) took both the revised and the original versions of the test. 30 people in this group were known to have dementia.
The researchers found the new test was:
- accurate; it identified people with dementia and hearing problems with only small differences between the new items and the rest of the standard test
- reliable; 28 people (10 with normal cognition and 18 with dementia) scored similarly when retested 2 to 4 weeks after their initial test.
People who had spent more than 12 years in education tended to score higher than those who hadn’t. This effect is also found for the standard MoCA test. Adding 2 points to the scores of people who had spent 12 years or less in education (the adaptation made for the standard test) increased its reliability.
Women were more likely to have lower scores on the revised test than men; this was not corrected by adding 2 points to women’s scores.
Why is this important?
The revised test is the first fully validated, sensitive and reliable cognitive test for people with hearing problems and is now available for use. It closely matches the standard test for identifying dementia in people with hearing loss. It asks similar questions, takes a similar length of time to complete and assesses the same cognitive areas.
Women had lower scores than men, so there could be sex bias in the new test. The researchers say the reasons for this need to be explored further, in line with a growing emphasis on sex and gender considerations in this field of research (cognitive neurosciences).
Translated versions of the revised MoCA test performed differently in other languages (French and Greek). This could be down to differences in how dementia is diagnosed; cultural or language differences could also have an effect. The researchers say this warrants further investigation.
To date, this test has been assessed only in people who developed hearing problems; it may not be an effective test in people who were born with hearing loss. Another test exists for people who use sign language. Research is needed to develop a test for people with visual problems.
What’s next?
The test meets an international need for a reliable test to identify cognitive impairment among people with hearing loss, the researchers say. The test is being translated and validated in Arabic, Greek, German and Portuguese.
You may be interested to read
This summary is based on: Dawes P, and others. Development and validation of the Montreal cognitive assessment for people with hearing impairment (MoCA‐H). Journal of the American Geriatrics Society 2023;1-10.
An article from the Social Care Institute for Excellence about hearing loss and dementia.
An article from the Royal National Institute for Deaf People about the increased risk of dementia with hearing loss.
A toolkit for clinicians can be found on the SENSE-Cog website.
The revised MoCA test, and the standard version, can be found online.
Funding: The study was funded by the European Union's Horizon 2020 programme. The lead author was supported by the NIHR Manchester Biomedical Research Centre.
Conflicts of Interest: One of the authors is the copyright owner of the original (MoCA) test.
Disclaimer: Summaries on NIHR Evidence are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that the views expressed are those of the author(s) and reviewer(s) at the time of publication. They do not necessarily reflect the views of the NHS, the NIHR or the Department of Health and Social Care.
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