How Johns Hopkins researchers found a way to curb excessive skin cancer surgery

BALTIMORE—When patients have skin cancer, their doctors will often perform what's called Mohs micrographic surgery (MMS)—a technique of removing cancerous tissues from the skin one layer at a time.

But there are wide variations between surgeons when it comes to just how much tissue is removed, with some doctors regularly removing more amounts of tissue than others. It's a phenomenon that not only creates large cost differences for some patients but raises questions about the appropriateness of the care patients are receiving.

A recent study looking to curb the extreme overuse of MMS found a way to cut overuse of the procedure and save Medicare $11 million in about a year's time: Send letters directly to surgeons telling them how much more they were doing compared to what other surgeons were doing.

Of the group of surgeons that received a "Dear Colleague" letter, 83% of surgeons who were identified as outliers improved their MMS behavior by the first quarter of 2017, according to the study published this week in the journal JAMA Dermatology. When researchers returned a year later, that decrease had been sustained, they said.

RELATED: Medical errors officially the 3rd leading cause of death in U.S., study finds

The estimated cost of sending the letter was about $150,000, or about $144 per surgeon.

"Where else do you get that kind of return on investment or surgeon behavior change?" said Martin Makary, M.D., senior author of the study and a professor of surgery at Johns Hopkins University School of Medicine, speaking at the Association of Healthcare Journalists Conference in Baltimore on May 5. 

Changing behavior

The study was part of the Improving Wisely effort and was supported by a grant from the Robert Wood Johnson Foundation.

The researchers decided to look at the MMS procedure—which was developed by Frederic Mohs at the University of Wisconsin in the 1930s, because it is seen as a highly effective and efficient approach to addressing one of the most common types of cancer. There are more than 5.4 million cases of skin cancer diagnosed a year at a cost of $8.1 billion. 

But there also is some wide variation in its use, and while some surgeons may overtreat the patients using the MMS procedure due to insufficient technical expertise, researchers point out overuse may also be tied to the current fee-for-service payment model.

Surgeons are paid based on the number of stages performed per tumor, "creating a perverse incentive for a surgeon to use an excessive number of staged resections to remove a lesion," the team wrote in the study. In other words, they may cut too much during surgery, quite possibly, because they'll get paid more to do it.

RELATED: Study: Artificial intelligence can diagnose skin cancer as well as doctors do

To conduct the study, researchers looked at more than 2,300 U.S. surgeons that conduct the MMS procedure. Researchers used Medicare Part B claims data that showed surgeon-level data and the claims forms for how many stages were performed per MMS procedure to identify which surgeons were outliers in their profession.

In the non-randomized controlled intervention study, they selected a group of surgeons who were outliers and sent a letter to some of them informing them of their performance. The other portion of the group did not receive a letter.

They also selected a group of surgeons who were within the appropriate range of surgery use and sent some a performance evaluation letter while sending the others no letter.

Performance among surgeons who were considered "inliers" and received notification letters remained largely unchanged. But among those who were outliers and received the notification, they observed the sustained drop.

They also found a drop in the non-notified outliers of about 69% and attributed the drop to an awareness campaign held by the American College of Mohs Surgery (ACMS) at the same time the letters went out, as well as the possible communications between surgeons who got the letters and those who didn't.

"We observed an immediate and sustained improvement in quality with a simple intervention based on the spirit of physicians helping one another," Makary said in a statement.

Similar efforts would benefit from the backing of a well-respective peer physician leadership group, as well as a clear achievable benchmark that is supported by leaders in the field, researchers said.