Dangers of Overdiagnosis and Overtreatment
Sidney M. Wolfe, M.D.
The cover story this month presents clear evidence against
inappropriately-frequent screening for osteoporosis. The more often these tests
are done, the more likely it is that many women who do not really have
osteoporosis will be herded into using drugs to prevent fractures. The drugs
will not help most of them and also have adverse effects.
One of the most important books concerning the dangers of
undergoing too many tests for a variety of diseases and conditions is Overdiagnosed:
Making People Sick in the Pursuit of Health, by Dr. H. Gilbert Welch, an
internist and professor of medicine at Dartmouth College. Welch discusses the
downside of drug treatment for women who really do not have osteoporosis.
In the book, he reviews a study attempting, with drugs, to
increase the bone density of women who have, at the start, near-normal bone
density (osteopenia) and who have never had a fracture. The results are best
summed up in the example of 100 patients diagnosed with near-normal bone
density and treated with osteoporosis-prevention drugs for a lifetime.
- Winners (treatment saved them from a fracture): 5
- Treated for Naught (had fractures despite treatment): 44
- Losers (overdiagnosed: treatment couldn’t help them
because they never were going to have fractures): 51
These results show that for every 100 such women, there are
only five winners (saved from a fracture) but 95 women who had fractures
despite treatment or could not have been helped by treatment because they were
not going to have fractures.
Aside from the poor odds, for most such women, of benefiting
from drug treatment, there are other downsides. As Dr. Welch points out,
referring to bisphosphonates such as alendronate (Fosamax), which increase bone
density, “There is some concern about the long-term effects of these drugs;
they may actually make bones more brittle by changing the bone architecture.
They can also disturb calcium metabolism, lead to ulcers in the esophagus and,
very rarely, cause bone to die.”
This is but one of many examples of dangerous overdiagnosis
reviewed in this book. Heeding Welch’s clearly written advice will surely help
women with near-normal bone density, and others at risk of being overdiagnosed
and overtreated for other conditions, avoid the unnecessary tests, drugs,
surgeries and anxiety that are the inevitable outcome of our overdiagnosis