80 is not the new 70: Age may bias heart care, study finds

In this Thursday, April 19, 2001, file photo, a surgeon and assistants perform open heart bypass surgery on a patient at a hospital in Mesa, Arizona. oru Kawana/East Valley Tribune via AP photo

People are more likely to buy things when prices end in 99 cents rather than when rounded up to the next dollar, or they choose cars with mileage under 1,000 instead of past that mark. Now researchers said something similar might be happening with age perception and heart surgery.

A U.S. study out Wednesday, Feb. 18, found that heart attack patients who turned 80 within the previous two weeks were less likely to get bypass surgery than those who were two weeks shy of that birthday, even though the age difference is less than a month.

Guidelines do not limit the operation after a certain age, but doctors may be mentally classifying people as being “in their 80s” and suddenly much riskier than those “in their 70s,” study leader Dr. Anupam Jena of Harvard Medical School said.

The reason may be “left-digit bias,” which is the tendency to focus on the first number.

“When you go to a store and the item is $4.99, you’re more likely to buy it than if it’s $5,” but there’s no similar effect when prices are $4.50 versus $4.51, Jena said.

“That penny matters more when you’re crossing a threshold” to a new dollar amount, he said.

It poses a serious concern in health care. Although a less invasive treatment, an artery-opening stent procedure, is often the treatment for a heart attack, bypass surgery is preferred when many arteries are affected or in some other situations.

To see if left-digit bias affects who is offered that option, researchers studied Medicare records from 2006 through 2012 on 70,000 heart attack patients, including about 10,000 within two weeks of their 80th birthday. They found that 5.3% of the group that just turned 80 had bypass surgery versus 7% of those slightly younger.

They also looked at other birthdays, such as 77 versus 79 and 81 versus 83 and saw no difference in rates, suggesting that crossing 80 was a key mark.

Death rates during the first two months after the heart attack were higher among those over 80, suggesting they might have been harmed by not being offered surgery, Jena said.

The New England Journal of Medicine published the work.

It can’t prove that mental bias is affecting surgery rates but an independent expert, Dr. John Spertus, director of health outcomes research at Saint Luke’s Mid America Heart Institute in Kansas City, Missouri, said it makes a strong case.

“I believe that these types of cognitive biases are rampant in medical decision-making, and this is a very clear demonstration of the phenomenon,” he said.

Spertus has developed risk assessment tools that rely on more objective factors to guide care.

Marilynn Marchione can be followed on Twitter at http://twitter.com/MMarchioneAP.

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The Associated Press is solely responsible for all content.