Routine testing for dementia could find three times as many cases

Researchers say everyone should be screened when they reach a certain age. Flickr/Guig25

A routine test could triple the rate of detection of cognitive impairment and dementia, according to researchers who argue that screening should be mandatory for older people.

The controversial proposal would dramatically boost early diagnoses of dementia, “a common and costly problem”, the researchers say. But one Australian expert has described it as “a blatant example of age discrimination”.

A US team assessed the impact of screening - coupled with further evaluation - on diagnoses in people aged 70 and older who had no indication of memory loss.

Participants were given a brief test, in which they had to perform tasks such as drawing a clock and recalling certain words.

Of the 8,063 people who accepted screening, 2,081 failed and 580 agreed to further evaluation. In total, 902 - or 11% - of people were diagnosed with cognitive impairment, compared with 4% in clinics without the program, the researchers said.

Among those who failed the screening and accepted further evaluation, 432 were diagnosed with dementia. Of 118 patients who passed the initial screen but still requested further evaluation, 82 were diagnosed with dementia.

The findings were published in the Journal of the American Geriatrics Society.

Instead of offering to some people a definitive assessment for cognitive impairment, which required the time and skill of an experienced clinician, the health system should provide a simple, brief screen to all people of a certain age - “the quickest and most reliable way to identify individuals in need of further evaluation,” the authors wrote.

The study leader, Dr John Riley McCarten from the University of Minnesota, said: “Our study demonstrates that proactive strategies such as routine screening are well-accepted and effective in diagnosing cognitive impairment, and that primary care providers value the diagnostic and management services involved.”

The recommendation runs counter to recommendations by government and medical bodies in the US and Australia. A previous study has suggested that routine testing is more trouble than it is worth.

But Professor Colleen Cartwright, who directs ASLaRC Aged Services at Southern Cross University, went further and described it as “a blatant example of age discrimination that would frighten the life out of frail people for no good reason”.

Routine screening was notoriously inaccurate, she said, and produced as many false positive results as false negatives.

“Approximately 18% of people over 80 have dementia. Over 90 it’s 34%. But to listen to a lot of people, you’d think that absolutely everyone over 80 or 90 has dementia. And when older people hear that kind of talk, understandably it’s very frightening and depressing.

"You should only do screening when there is a good reason - a trigger. Just because someone is 80 or 90 does not mean they should be screened. Just because someone made a bad decision is not enough. Hands up anyone who hasn’t made a bad decision.”

Professor Cartwright said that routine screening “medicalised” the normal process of aging, and had the potential to induce enough distress in some people that it tipped them “in that direction when they might not have gone that way”.

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