(Matthew Staver/Bloomberg)

BOSTON — I’m at the New America Foundation conference on how to avoid avoidable care, and things here are getting grim.

It turns out we’re in the middle of an epidemic — a tonsillectomy epidemic, to be more specific. Tonsillectomies are the most common procedure, for children, requiring anesthesia. And we’re doing more of them: The number of tonsillectomies performed spiked by 74 percent between 1996 and 2006. In 2006 alone, more than a half-million children in the United States got their tonsils removed. The only problem is there’s no evidence they work for most children.

The procedure does show some benefits for those with really serious symptoms — very sore throats, fevers and other symptoms at least seven times in the past year — but no improvement for those whose indications are milder.

Tonsillectomies are often used to treat sleep apnea, a condition where an individual has trouble sleeping. Not a single, randomized study, however, has actually tested whether that’s true.

“It’s a silent epidemic of unnecessary care,” says the Dartmouth Atlas’s David Goodman, who spoke here this morning. “In most instances, it’s done for patients with much less recurrent symptoms than should be indicated. I think a lot of this is unbeknownst to providers.”

The aim of this conference, which lasts through tomorrow, is to better understand why we use medicine that doesn’t make us any healthier. And it’s a pretty tough question to answer, even when you focus on just one, simple procedure. At the same time, it’s an important one: Unnecessary health care is estimated to cost at least $158 billion every year.

“Is it about parent demand? Patient preferences? I think some of this occurs within a fog of ignorance,” says Goodman. “Often these patients are led by well-meaning clinicians along this path.”

Patient demands have emerged as one driver of unnecessary care in discussions here this morning; doctors often find themselves acquiescing to patients’ demands for a given test or treatment. Economics have come up a lot: Most doctors are paid for the volume of services they provide, creating an incentive to provide more care even if it might not be indicated.

That does not quite explain the surge in tonsillectomies: As a relatively simple procedure, it’s not one that will bring in significant revenue, in the way that more complex treatments, such as those for cancer and end-of-life issues, would. “There’s not a lot of money in tonsillectomies compared to end of life care,” says Goodman. “Providers are by and large well-meaning here.”

Goodman and others have focused a lot on the medical education system as one key culprit. Medical school often focuses on teaching how best to treat patients, with little time spent discussing when treatment doesn’t make sense.

“Our biggest failure today,” he says, “Is our educational system. Medical schools and graduate schools are failing us deeply. We need to move some of these ideas about the evidence being uncertain into the beginning of education. There’s been such little work on that.”