There is no evidence base for proposed dementia screening

Although we welcome the government’s attention to dementia and its timely diagnosis, we are writing to express concerns about the potential consequences of the recent announcement by the health secretary of a “dementia case finding scheme.” The proposal is that doctors should “proactively” ask patients at risk of dementia—including all those aged 75 or over—about their memory, and offer a screening test.1 2

This proposal has moved beyond the raising of awareness about dementia and amounts to a clear intention to screen a section of the population for the condition, without the articulation of any evidence that it fulfils the established criteria for screening. This could lead to overtreatment, harm to patients, unnecessary expense, and diversion of precious resources away from other services, including support for people who are seeking help for a timely diagnosis of dementia or who have already been given a diagnosis. We argue that before any screening programme is introduced it must be shown that the benefits outweigh any potential harm.3 Screening for dementia must be assessed in the same way as any other screening intervention.

We acknowledge the prevailing view that early diagnosis (if an accurate diagnosis were possible) might allow more time for patients and families to make decisions on their living accommodation and other aspects of care while the patient is functioning at the highest possible level. However, until we have clear evidence from well designed trials of the benefits and harms and the cost implications of early—as opposed to “timely” (that is, at the right time for that person)—diagnosis, we believe that such decision making would be better accomplished by all patients, irrespective of any diagnosis, while they are still relatively fit and well. This might occur, for example, at the time of their eligibility for a free bus pass. This is particularly important given that a substantial proportion of the older population will die with dementia or severe cognitive impairment.4

Although we welcome the government’s emphasis in the NHS mandate on improving care of people with dementia,5 the proposal to assess a prescribed section of the population for memory problems amounts to a non-evidenced population screening programme that has not been subjected to the same scrutiny as other such programmes. In June 2010 the UK National Screening Committee, whose remit is to advise the government on all screening programmes, advised very clearly that screening for Alzheimer’s disease “should not be offered.”6 The full report analysed the case for screening against the widely accepted Wilson-Jungner screening criteria published by the World Health Organization. It concluded, “The analysis of the literature against the above criteria indicates that the implementation of an evidence based routine screening programme for Alzheimer’s disease that will reduce mortality and morbidity is not yet a possibility.”

We have to ask why the government has proposed a policy that is directly contrary to the advice from the National Screening Committee.

Unlike in most other NHS screening programmes, patients are not to be invited for screening for dementia; instead healthcare professionals would have to screen opportunistically, such as when patients were admitted to hospital or visited their general practitioner. This means that patients, or their relatives or carers, would not have prior warning of the screening test or an opportunity to be informed of the potential benefits or harms of screening. The lack of provision of information and of choice to patients in this proposal are major concerns. Of course, where general practitioners or other healthcare professionals had reason to believe that the patient’s symptoms might be due to dementia they could still carry out an assessment of memory and refer appropriately. However, this is very different from “screening” asymptomatic individuals identified just by virtue of attending the surgery.

While the healthcare profession needs to work together to help reduce the stigma associated with dementia, the diagnosis remains a frightening one, and one of which the public, thanks to the success of awareness campaigns, is now very mindful. We should not underestimate the potential negative effects of such a diagnostic label.

The NHS mandate itself states, “Dementia is the illness most feared by people in England over the age of 55.”5 And a recent study on the impact of a dementia diagnosis concluded, “Being told one had dementia had a big impact on a patient’s identity and often caused feelings of loss, anger, fear, and frustration.”7

If patients became aware that a visit to their GP could result in their being “examined” for a diagnosis of dementia, irrespective of the reason for their attendance, there would be a very real danger that some patients might avoid seeking help from their GP when it was needed.

Although drug treatment can help to improve the symptoms of dementia, WHO’s 2012 document Dementia: A Public Health Priority states, “No treatments are currently available to cure or even alter the progressive course of dementia,” reflecting the lack of evidence that early drug treatment alters the course of the disease.8 There is a danger that screening for dementia would result in patients simply being treated for longer, at extra cost to the NHS, but with no benefit to the patient.

We agree with the government that dementia services need to improve and should be based on evidence—otherwise we are likely to divert resources from those areas of proved benefit to those with only belief to support them. The priority needs to be on improving access to diagnosis and on support for patients and their families who are already seeking help—a huge challenge that will require major investment. The proposed screening programme not only lacks an evidence base or a proper assessment of potential harms but would divert much needed funds from this important work and overwhelm an already overstretched service.