Call to rethink diagnosis methods

Many patients are being “overdiagnosed” and given unnecessary medical treatment for problems that will never harm them, says new research. The study has featured prominently in the press, with the Daily Mail reporting “a plague of overdiagnosis”, and The Independent saying that “an over-reliance on healthcare threatens to bankrupt the world”.

The article, published in the British Medical Journal, argues that overdiagnosis poses a significant threat to human health by labelling healthy people as sick and wasting resources on unnecessary care. Overdiagnosis is when somebody is diagnosed and treated for a condition that is unlikely to cause them harm.

The authors of the report say there is growing evidence that “too many people are being overdosed, overtreated and overdiagnosed”. For example, they say, research has found that almost a third of people diagnosed with asthma may not have the condition, while up to one in three breast cancers detected by screening may actually be harmless.

The authors state that overdiagnosis is when a person without symptoms is diagnosed with a disease that will not cause them to experience symptoms or early death. More broadly defined, overdiagnosis refers to the related problems of increased dependence on medical care and overtreatment, which leads to healthy people with mild problems or at low risk being “reclassified as sick”.

As a result of overdiagnosis people potentially face the harms of unnecessary tests and side effects from treatment, and resources that could be directed at other patients are wasted.

The authors of this new article say that many different factors are driving overdiagnosis, but a key contributor is technological advance. Tests and diagnosis methods are now so numerous and sensitive that even the tiniest of harmless abnormalities can be detected, they argue.

The authors say that people can be overdiagnosed and overtreated in a number of ways:

The authors say there is evidence that the problem of overdiagnosis may exist across many conditions (including those for which underdiagnosis may also be a problem) and cite research on overdiagnosis in several different areas. The authors provide their opinions on various examples of what they see as overdiagnosis:

To clarify, the above statements reflect the opinions of the study’s authors, not Behind the Headlines or NHS Choices.

The authors say that overdiagnosis is being driven by several factors, including:

The authors argue that action is needed to tackle the problem of overdiagnosis. They say that medical professionals should aim to differentiate between benign abnormalities and those that will go on to cause harm, while the public and professionals should be given “more honest” information about the risks of overdiagnosis, particularly related to screening.

The authors say new protocols are being developed to bring a more cautious approach to the treatment of incidental abnormalities. They say consideration should be given to raising the thresholds of what is defined as abnormal – in breast cancer screening, for example. At a policy level, reforming the process of defining disease is urgently required, they argue, to rule out financial or professional conflicts of interest.

The authors point out that concern about overdiagnosis does not preclude awareness that many people with genuine illness miss out on healthcare. They argue that resources wasted on unnecessary care can be much better spent treating and preventing genuine illness. “The challenge is to work out which is which.”

This is a powerfully argued and controversial article that claims that many people are being overdiagnosed and overtreated for mild problems that may never cause them harm. It is timed to coincide with the announcement of an international conference on the topic, which will take place next year, partly hosted by the BMJ and Bond University, where some of the authors are based. It should be noted that the article is not a systematic review of the evidence on screening or on overdiagnosis, but a strong opinion piece that cites research in support of the authors’ argument.

Nevertheless, the paper is a useful contribution to the complex debate about how far healthy people should be screened or tested, and how far conditions that may or may not cause harm in the future should be treated. It’s a difficult subject that provokes strongly opposing views among doctors and researchers. For example, a recent paper published in The Lancet argued that everyone over 50 should be given statins because they have been found to reduce the risks of heart attacks even in healthy people.

The article raises a number of concerns about cancer screening in particular, and it should be noted that in the UK the Department of Health announced last October that a full review of the potential risks and benefits of the NHS Breast Cancer Screening Programme is to take place. In terms of cancer screening, much will depend in the future on how far researchers are able to discriminate between ‘harmless’ slow growing cancers that do not need to be treated and those that are more aggressive.

The article should be seen in the context of previous advances in technology and treatments that have brought established benefits in terms of detecting certain conditions early. For example, high blood pressure is symptomless, but it is a recognised risk factor for cardiovascular disease, and there is good research to show that treatment to reduce high blood pressure saves lives.

Overall, the concept of overdiagnosis is one that needs careful consideration, particularly how its potential harms relate to the potential harms of failing to diagnose a disease. Is it better to risk side effects in patients than to risk missing a serious health problem? The issue is perhaps too big to cover in a single article, although this latest opinion paper raises some extremely interesting and thought-provoking points on the issue. Perhaps the key thing now is to look at overdiagnosis on a condition-by-condition basis, for example in the way that alleged overdiagnosis in breast cancer screening is being examined in the UK.

Although there are clearly strong feelings on both sides of the overdiagnosis debate, examinations of the issue should be as comprehensive, objective and evidence-based as possible and focus on specific topics. Overdiagnosis of one condition could be problematic, while it might produce few negative results for other conditions. Next year will see an international conference on the issue of overdiagnosis, which should stimulate both debate and research on this important issue.