Why you should care
Because mortality statistics guide how public health resources are allocated.
New York City, in the early aughts, had one of the highest rates of heart disease deaths in the nation. Nearly 40 percent of deaths there were attributed officially to heart disease, according to Bob Anderson, chief of the mortality statistics branch at the National Center for Health Statistics.
But the statistic didn’t align with New York’s risk factors for heart disease — most notably, smoking, obesity and high blood pressure — which should’ve put the city at or below the 2003 national average of roughly 28 percent. So the NYC Health Department launched a validation study of death certificates across the area’s 70 hospitals in 2010. It found a 91 percent overreporting of coronary heart disease (CHD) as the cause of death.
Finding mistakes on death certificates is not just a New York City problem — it’s widespread. In fact, according to various studies:
Roughly a third of U.S. death certificates include an inaccurate cause of death.
It’s bad enough to imagine doctors or coroners getting such details wrong. But it’s also a concern because mortality data is used to track common and emerging illnesses, which can influence how resources are allocated. That means overreported conditions, like heart disease, can be disproportionately weighted in public health decisions, while underreported conditions may be overlooked and underfunded.
“We don’t really have a good sense for how accurate death certificates are,” admits Anderson. Based on “well-conducted studies,” he sets his own estimate of inaccurate causes of death nationwide at 20 to 30 percent.
Other recent reports paint a bleaker picture. A 2017 study of Missouri hospitals, for example, found that 48.5 percent of death certificates reported an incorrect cause of death. A smaller 2017 study in Maine came back with a 33 to 40 percent inaccuracy rate, while a startling report from Vermont found “major errors” in 51 percent of death certificates.
“Most of us trained at similar institutions, so it’s not necessarily a question of the location of the patient,” says Dr. Emily Carter, author of the Maine study and a physician at Maine Medical Center. “It’s almost more of a question of where did the provider train, and did their institution have teaching around certification.”
Anderson argues that studies on death certificate inaccuracies are poor indicators of the true extent of the problem because results vary so widely. But where they help, he says, is by underscoring how hard it is to accurately assign a cause of death.
Most doctors don’t wake up in the morning and think, ‘I want to lie on a death certificate today.’
Dr. Barbara Wexelman, TriHealth Cancer Institute
Dr. Barbara Wexelman, a breast surgeon at the TriHealth Cancer Institute in Cincinnati, says that determining the underlying cause of death for a certificate can be especially difficult if a patient dies suddenly or at a hospital where doctors are unfamiliar with his or her medical history.
At most hospitals, Wexelman continues, it falls to the lowest person on the totem pole to fill out the death certificate — she did her share as a resident in New York City. Not only had she never been taught how to complete the form, the electronic system, she says, didn’t even list every possible cause of death. In one case, Wexelman recalls, a patient’s immediate cause of death was sepsis, but the system required her to enter what had caused the sepsis. Unsure of the underlying cause, she made her best guess.
“Most doctors don’t wake up in the morning and think, ‘I want to lie on a death certificate today’ … Everyone’s trying to be as accurate as possible,” Wexelman says. “Many times we don’t know why a patient died, but the system sort of forces you to put something, and that may not be the most accurate diagnosis.”
Still, Wexelman’s experience spurred her to run a study on what NYC resident physicians thought of the death certification reporting system, and the result was shocking: Nearly half of the residents said they had knowingly reported an inaccurate cause of death. Wexelman says this stems either from being forced to enter a cause of death when the resident simply didn’t know the right answer or entering a cause of death that was the best of the limited choices on the form but didn’t exactly match their understanding of why the person had died.
Inadequate training is an obvious part of the problem, but there also needs to be better communication about why these certificates are so important for mortality statistics, Carter says. As for the fundamental hurdle — the difficulty in identifying a cause of death — that may never be cleared. The process, Anderson explains, is “part art, part science,” which suggests that some inaccuracy is inevitable.
“We have to, I think, accept a certain amount of error,” Anderson says. “But if everyone does their best, I think we’re in pretty good shape.”