There's a growing pushback in American medical care -- and across the developed world -- to be less aggressive about looking for certain diseases in patients.
After decades spent developing and encouraging the use of a dizzying array of diagnostic tests and risk-classification schemes, many professionals are moving toward doing less because they fear patients are being harmed by overdiagnosis.
In some cases, harm may come from the tests themselves. Researchers have estimated that the more than 10,000 computerized tomography machines in the U.S. deliver unnecessary radiation doses 50 to 500 times greater than regular X-rays to more than 20 million people a year.
Although the radiology community has disputed those estimates, there has been a concerted effort by regulators and others to reduce dosage in the past few years, particularly for children.
But for most diagnostic tests, the worry is that benefits have been oversold, that screening may produce ambivalent results at best, or false positives that bring on more tests or needless treatment.
Several recent analyses calculate needless tests and resulting over-diagnoses cost the country's health care system $200 billion or more each year.
The greater concern, though, is that patients are worrying and receiving therapy for conditions that are unlikely to harm them, much less kill them.
One large Canadian study found recently that almost a third of people diagnosed with asthma might not actually have the condition. A recent mega-review indicates up to one in three breast cancers detected through screenings may be overdiagnosed. Millions of people have been added to the ranks of those afflicted with "pre" diabetes, hypertension, or dementia, with no guarantee in many instances that early markers will mean disease will follow.
"Increasingly, we've come to regard simply being 'at risk' of future disease as being a disease in its own right," said Ray Moynihan, a senior fellow at Bond University in Australia and one of three authors of a report on the threat to human health posed by overdiagnosis published online by the British Medical Journal in late May.
He and his colleagues argue that many factors are driving the trend, including more sensitive technology that detects smaller and smaller "abnormalities" along with broader disease definition and lower thresholds for care.
Critics have long blamed excessive testing on legal concerns, cultural issues, professional turf wars and commercial incentives. And doctors and patients have long wrangled over how many tests or procedures should be used, but only recently have both been forced to consider how expensive care may be and how worthwhile.
One person's evidence-based medicine is another's first step toward "rationing health care,"' with organizations like the U.S. Preventive Services Task Force being accused of undermining screening with suggested limits on things like mammograms for younger women or prostate specific antigen tests for men of any age.
Likewise, a recent recommended list of tests that should be dropped or restricted from a group of medical specialty organizations was also met with suspicion in many circles.
The next big session on overdiagnosis is set for September 2013, when Dartmouth University and several partners will hold an international conference on preventing it. Dartmouth researchers have been in the lead at spotting uneven trends in the way health care is provided here and abroad for several decades.
Moynihan and his coauthors said the worry about overdiagnosis doesn't mean that millions of people are not still endangered by not receiving enough medical and preventive care, too. The key is treating and preventing real illness, and not "pseudo disease" they contend.
"The challenge is to work out which is which, and to produce and disseminate evidence to help us all make more informed decisions about when a diagnosis might do us more harm than good," they conclude.
(Contact Scripps Howard News Service health and science writer Lee Bowman at BowmanLshns.com)