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Dementia – new data, old rhetoric?

The purpose of this blog is to respond to the headlines, reacting to health stories and trying to look beneath the surface - usually by asking the question ‘Why?’ The problem with this approach, of course, is that it relies on the important stories actually reaching the headlines in the first place. The sensationalist world we live in ensures that a study which shows that tomatoes/chocolate/phone masts might be linked to increased/decreased risk of cancer/heart disease/impotence, will always attract more media attention than, for instance, a technical study into the prevalence of dementia in the over 65’s.

For GPs, however, this particular study is of real life importance, because it affects diagnosis rates - something which is being continually used to bash us with, and a key driver of Government policy.

So it is with no sense of surprise that the publication of one of the most significant studies into the demographics of dementia has gone unnoticed by the press. Not only does it lack the ‘wow’ factor, but it is a good news story. For a headline to grab attention it needs to ‘make them laugh, make them cry, or make them angry’. Against these criteria, a news angle of ‘fewer of us are getting dementia than we thought’ doesn’t quite cut the mustard. Perhaps more importantly, it is not evidence that the Department of Health or the Alzheimer’s Society are likely to welcome - since it goes against their rhetoric. Both have pushed hard with the notion that dementia diagnosis rates are ‘shockingly low’ and used this to drive their quest to ‘case-find’ (the new, more palatable word for screening) in order to drive these rates up. If the rates are not as low as they have been telling us, this could question the direction of travel - so no one in Government or the charitable sector is pushing the press to report this study. They would rather it stayed quietly in the background, for academics to discuss and the rest of us to ignore.

The problem with estimating the diagnosis rate of dementia, is that while we know how many people have been diagnosed (the GP Quality and Outcomes Framework provides this data), we don’t know how many people are undiagnosed. How could we? By definition we don’t know about them. The denominator in the equation, therefore, has to be based on prevalence estimates: how many people would we expect to be diagnosed? 

Up until now, much of the data used for these estimates has been over 20 years old (five of the six studies included in the Delphi Expert Consensus Report into prevalence were published before 1994, and the sixth in 1998). A new study, led by Carol Brayne’s team in Cambridge, has brought these figures up to date by repeating a study first conducted in 1991. Part of the strength of the study is the use of the same methods, thus making the two pieces of research directly comparable. The key finding is that there has been a significant fall in the prevalence of dementia, from 8.3% to 6.5%, Which means the estimated number of people with dementia in the UK has fallen from 884,000 to 670,000.

If the denominator in the equation has fallen by nearly a quarter, then the diagnosis rates will go up by a factor of nearly 4/3 - meaning the oft-quoted rate of 46% has risen to over 50% in the blink of an eye, and the convenient sound bite that ‘less than half the people with dementia have a diagnosis’ no longer holds water.

Will the Government change its figures in the light of this significant research? I very much doubt it, but we should hold them to account every time they fail to do so and challenge policies that seek to achieve an arbitrary diagnosis rate, while failing to address what patients and their carers really want - which is quick access to a diagnosis when they need it and hands-on post-diagnostic support.

I would like to make one last prediction: the Government will come around and acknowledge this new data, but it will be in a couple of years’ time, probably just before the general election. When the time comes, they will quietly sneak in the new denominator to show how much the statistics have improved, and congratulate themselves on how well their plan is working. You heard it here first.

Dr Martin Brunet is a GP in Guildford and programme director of the Guildford GPVTS. You can tweet him @DocMartin68

The Mental Health Forum is a unique event bringing together GPs, senior registrars and consultants caring for people with mental health conditions.

It provides clinical updates on key topics as well as unparalleled networking opportunities. This year’s event will equip clinicians to deal with the clinical challenges they face in today’s NHS, including comorbidity and dementia.