Peter Eisler and Barbara Hansen:

“If we ever learn about it at all, it’s only after the fact, if something goes wrong and the patient sees another doctor, or if Medicare or someone else comes in retroactively and does an audit,” says Rosemary Gibson, an authority on patient safety and author of The Treatment Trap, a book on unnecessary care. “The system, in my opinion, doesn’t want to know about this problem.”

Academic studies have discovered high rates of unnecessary surgery, particularly in spinal and cardiac operations.

A 2011 study in the Journal of the American Medical Association reviewed records for 112,000 patients who had an implantable cardioverter-defibrillator (ICD), a pacemaker-like device that corrects heartbeat irregularities. In 22.5% of the cases, researchers found no medical evidence to support installing the devices.

Another 2011 study, in the journal Surgical Neurology International, evaluated 274 patients with neck and back complaints over a one-year period: More than 17% had been told they needed surgery but had no neurological or radiographic findings that indicated an operation was necessary.

“I am seeing more and more patients who are told to have operations they don’t need,” says the spinal study’s author, Nancy Epstein, a neurosurgeon and chief of Neurosurgical Spine and Education at Winthrop University Hospital in Mineola, N.Y.