Screening for Minor
Memory Changes Will Wrongly Label Many With Dementia, Warn Experts
A
political drive, led by the UK and US, to screen older people for minor memory
changes (often called mild cognitive impairment or pre-dementia) is leading to
unnecessary investigation and potentially harmful treatment for what is
arguably an inevitable consequence of ageing, warn experts.
Their
views come as the Preventing Overdiagnosis conference opens in New Hampshire,
USA today (10 September), partnered by BMJ's Too Much Medicine campaign, where
experts from around the world will gather to discuss how to tackle the threat
to health and the waste of money caused by unnecessary care.
They
argue this policy is not backed by evidence and ignores the risks, harms and
costs to individuals, families and societies. It may also divert resources that
are badly needed for the care of people with advanced dementia.
Dementia
is age related and with an ageing population is predicted to become an
overwhelming and costly problem. But the evidence suggests that while 5 -- 15%
of people with mild cognitive impairment will progress to dementia each year,
as many as 40 -70% will not progress and indeed their cognitive function may
improve.
Studies also show that the clinical tools used by doctors to diagnose
dementia are not robust, and that many people who develop dementia do not meet
definitions of mild cognitive impairment before diagnosis. But this has not
deterred countries from developing policies to screen for pre -dementia.
For
example, in the US, the Medicare insurance programme will cover an annual
wellness visit to a physician that includes a cognitive impairment test. In
England, the government has announced that it will reward general practitioners
for assessing brain function in older patients -- and has committed to have
"a memory clinic in every town and every city" despite no sound
evidence of benefit.
This
had led to the development of imaging techniques and tests that are
increasingly used in diagnosis, despite uncertainty over their accuracy, say
the authors. The researchers say however, that until such approaches are shown
to be beneficial to individuals and societies they should remain within the
clinical research domain.
Furthermore,
there are no drugs that prevent the progression of dementia or are effective in
patients with mild cognitive impairment, raising concerns that once patients
are labelled with disease or pre-disease, they may try untested therapies and
run the risk of adverse effects.
They
also question whether ageing of the population is becoming a "commercial
opportunity" for developing screening, early diagnosis tests and medicines
marketed to maintain cognition in old age.
The
desire of politicians, dementia organisations, and academics and clinicians in
the field to raise the profile of dementia is understandable, write the
authors, "but we risk being conscripted into an unwanted war against
dementia."
They
suggest that the political rhetoric expended on preventing the burden of dementia
would be much better served by efforts to reduce smoking and obesity, given
current knowledge linking mid-life obesity and cigarettes with the risk of
dementia.
"Current
policy is rolling out untested and uncontrolled experiments in the frailest people
in society without a rigorous evaluation of its benefits and harms to
individuals, families, service settings, and professionals," they
conclude.
Story Source:
The
above story is based on materials provided by BMJ-British
Medical Journal.
Note: Materials may be edited for content and length. For further
information, please contact the source cited above.
Journal Reference:
1.
D. G. L. Couteur, J.
Doust, H. Creasey, C. Brayne. Political drive to screen for
pre-dementia: not evidence based and ignores the harms of diagnosis. BMJ,
2013; 347 (sep09 21): f5125 DOI: 10.1136/bmj.f5125
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BMJ-British Medical Journal (2013, September 10). Screening for
minor memory changes will wrongly label many with dementia, warn experts.ScienceDaily.
Retrieved September 10, 2013, from http://www.sciencedaily.com/releases/2013/09/130910095406.htm