This week’s BMJ provides a useful overview of the issue of screening for dementia. I have always argued that a push for “early” diagnosis, using what are in effect screening tools for cognitive impairment, carries with it risks of mis-diagnosis and over-diagnosis. I have found it very difficult to make my voice heard in raising these concerns about potential harm to patients. Several years down the line, following significant personal consequences of persistently arguing this point, I find that the UK National Screening Committee has come to exactly the same conclusion:
In the section highlighted above the Committee identifies twice as many false-positive as genuine diagnoses of dementia using current tests.
Dr McCartney raises one possible explanation of why the UK National Screening Committee’s advice regarding dementia, which is no different from its advice of 2010, was effectively ignored by governments, charities and healthcare professionals. My concerns about conflicts of interest influencing policy developments led me to petition the Scottish Government for a Sunshine Act.
I have a continuing concern that the figures quoted by the UK National Screening Committee refer to people aged 65 years and over. A considerable proportion of the people that I see are over 80 years. Given the parabolic distribution of cognition with age it is possible that the rates of false-positive diagnosis could be higher in this age group.