In 2002, the New England Journal of Medicine published a landmark study that found a common knee surgery used to alleviate joint pain was no more effective than a fake procedure in which a surgeon simply pretended to operate.

What was even more surprising was that over a decade later, the number of these procedures performed in the U.S. was still growing­ — and had reached over 700,000 a year. And this scenario is not unique to knee surgery. Very few studies like the New England Journal of Medicine study are ever performed, and when they are, their results don’t always change how doctors treat patients.

Hundreds of billions of dollars are spent each year on tests and procedures that are either completely useless or not effective enough to justify the cost, estimates Eric Patashnik, who teaches public policy and political science at Brown University. He is also a co-author of the book "Unhealthy Politics: The Battle Over Evidence-Based Medicine." 

“Some experts believe that less than half of all medical care is based on adequate evidence of its effectiveness,” Patashnik said.

In 2009, there was an effort, tied into the Affordable Care Act, to allocate government funding toward research that would compare the effectiveness of different treatments for the same condition. However, this became a partisan issue when then-Gov. Sarah Palin claimed that it would lead to “death panels” that judged who was worthy of medical treatment.

“There was a strategic incentive to attack that effort as leading to rationing and death panels or all the kinds of negative associations,” Patashnik said. “One of the casualties of the debate over the Affordable Care Act was this bipartisan technocratic idea got caught up in this other debate.”

Patashnik says part of the challenge with changing the medical system is that the industry oversees itself.

“What we found in our research is that the American health care system is really based on a social contract where we sort of delegate authority to the medical profession to govern our health care system,” Patashnik said. “The question then becomes, if doctors don’t exercise their professional authority consistently to make sure treatments are based on sound evidence, can politicians step in and correct that problem?”

Patashnik found that the answer to that question is no. If doctors do not accept the results of studies about the effectiveness of procedures, politicians have very little incentive to step in because their reputation almost always suffers.

“If you’re a politician, essentially, you cannot get on the opposite side of doctors, even if the science is on your side,” Patashnik said. “That is just a really risky place to be.”