sent to LRB just now after this http://www.lrb.co.uk/v37/n06/letters

Professor June Andrews says, of dementia that “The sooner someone sues a GP for failure to diagnose as early as possible, the better.” It is disturbing that Andrews, responding to Francis on the subject of dementia screening, is seemingly not aware of the evidence base.

Screening is always a balance of benefit and harm. The UK National Screening Committee exists to scrutinise where the balance of benefit vs risk lies, and this year, and unchanged with its’ previous pronoucements, stated that screening for dementia should not be offered. Why? False positives are rife. If the background rate of dementia for 65 year olds is 6%, screening would find 4 of the 6 (meaning that two are given a false negative result) but 23 other people would be told they have dementia when they do not. (1) This is not just bad medicine, but harmful medicine, and is why the UKNSC do not recommend it.

Further, Andrews promotes the use of litigation to drive earlier diagnosis. This creates several problems. When it is possible to diagnose dementia ‘earlier’? We know that imaging can pick up signals from within the older brain which may or may not be abnormal. Most will never progress to a clear pattern of dementia. Would Andrews like each of these patients to be told that they ‘might’ have early – or earlier – signs of possible future dementia? Should doctors do this in order to prevent litigation against them? What about mild cognitive impairment, MCI?  This is not ‘dementia’, but is also not clearly ‘early dementia’ – given that while  5-10% of people with MCI progress to dementia each year, but 40-70% of people with MCI actually improve. (2)What then? Would Andrews like to stipulate that all should be under the dementia ‘net’, just in case?

And then there is the real life situation where people have noted memory problems. Would Andrews like me to tell my severely depressed patient, in whom I am almost certain that their minor memory difficulties are related to their overwhelming illness, that they ‘might’ have dementia? Will this prevent  me being sued, even if my patient, distressed by this news, comes to harm through my desire to protect myself?

Instead, it is far better to try and achieve ‘timely’ diagnosis, which ensures that diagnosis is done carefully, sensitively and appropriately. The truth is that making a diagnosis of dementia can be difficult, and even the experts that we call on to assist us often find the diagnosis uncertain, and use time itself as a useful way of making the diagnosis clearer and more certain. Andrews is of the view that threatening doctors with litigation will do good. I argue that a culture of fear and ‘covering ones’ professional back’ has a great capacity to harm patients through testing and ‘too early’ diagnoses which do little good, or indeed cause harm for patients, while taking resources from the people most likely to benefit. And this is usually the people who do have dementia and who are left with little support in the community. This is where the focus should be.

As for the assertion that early diagnosis can result in interventions that can prevent later disability: there is a good argument that all older people should take steps to plan their future care choices, including power of attorney,  and stopping smoking, physical activity, and a healthy diet and social interaction can benefit us whether or not we have dementia. A recent study has shown that an early psychosocial programme for people with mild Alzheimer’s disease did not improve people’s functioning. (3) We should not make promises we cannot deliver on. If professionals cannot support each other in the delivery of good care, what hope is there for patients?

Yours sincerely

1) Clinical Recognition of dementia and cognitive impairment in primary care: a meta-analysis of physician accuracy. Acta Psychiatr Scand 2011; 124;165-83

2) Political Drive to screen for pre-dementia: not evidence based and ignores the harms of diagnosis. BMJ 2013; 347;f5125

3) Efficay of psychosocial interventions in patients with mild Alzheimers’ disease: the multicentre, rater blinded, randomised Danish Alzheimer Intervention Study. (DAISY) BMJ 2012; 345:e4693