There’s an excellent article published in the BMJ this week highlighting the increasing problem of “over diagnosis” (defined as “when people without symptoms are diagnosed with a disease that ultimately will not cause them to experience symptoms or early death”)
Medicine’s much hailed ability to help the sick is fast being challenged by its propensity to harm the healthy. A burgeoning scientific literature is fuelling public concerns that too many people are being overdosed, overtreated, and overdiagnosed. Screening programmes are detecting early cancers that will never cause symptoms or death, sensitive diagnostic technologies identify “abnormalities” so tiny they will remain benign, while widening disease definitions mean people at ever lower risks receive permanent medical labels and lifelong treatments that will fail to benefit many of them. With estimates that more than $200bn (£128bn; €160bn) may be wasted on unnecessary treatment every year in the United States, the cumulative burden from overdiagnosis poses a significant threat to human health.
Where’s the problem coming from? The authors discuss a number of the factors, but they pretty much boil down to an overly reductionist view of illness, commercial and vested interests in technologies and drugs, and fears of under diagnosis.
Drivers of overdiagnosis
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Technological changes detecting ever smaller “abnormalities”
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Commercial and professional vested interests
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Conflicted panels producing expanded disease definitions and writing guidelines
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Legal incentives that punish underdiagnosis but not overdiagnosis
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Health system incentives favouring more tests and treatments
- Cultural beliefs that more is better; faith in early detection unmodified by its risks
Heroes Not Zombies 
Thanks for posting this. I am concerned about the proposed DSM-V and changes to categories of disorder relating to cognitive loss.
Reply to Bad medicine: modern medicine: BMJ2012;344:e2346
From his frontline, Dr Spence states that he “fears soon all those with even mild cognitive impairment will be labelled with dementia.” Is this just another example of fear mongering by one of the most challenging feature writers for the British Medical Journal? Only time will perhaps tell, but for now let us consider what several authorities say about this subject.
Dr Allen Frances, chair of the DSM-IV Task Force has been a leading and vocal critic of the various draft releases of the forthcoming DSM-V classification. His very real fear is that that “DSM-V will cause further epidemics of ‘over-diagnosis’”. One area specific to such concern is the DSM 5 proposal to include Minor Neurocognitive Disorder as a “presumed prodrome” to Alzheimer’s Disease. Like me Dr Frances believes that biological testing for prodromal AD will be an important milestone in the clinical application of neuroscience. However to do so effectively we need to better understand the pathology behind Alzheimer’s disease. It is still the case that the details of the pathological cascade are not fully understood, far less the link with normal ageing processes and the role of environmental triggers.
Dr Frances believes that minor neurocognitive disorder “has necessarily to be based exclusively on extremely fallible clinical criteria that will have unacceptably high false positive rates – surely exceeding 50 percent. Why scare half the people taking the tests unnecessarily, especially when there is no effective treatment even for those who are true positives”’
In the Lancet Neurology, experts in the field of Alzheimer’s disease have attested that, whilst progress has undoubtedly been made on biological markers, much remains to be done in standardizing these tests, determining their appropriate set points and patterns of results, and negotiating the difficult transition from research to general clinical practice.
I cannot then reassure Dr Spence regarding this aspect of his “contagion of iatrogenic harm.” Furthermore, surely we can agree with Dr Spence that good medical practice should allow questioning of itself. Given such request, a blog article by Jesse Ballenger of March 2010 is worth reading: though two years old, it does not seem out of date.
“The draft of DSM-V does propose significant changes that, while well-intentioned, may greatly extend the medicalization of aging and worsen the stigma of age-associated cognitive decline.”