Jayne O'Donnell

USA TODAY

Medical errors kill about 250,000 people a year, a new study from a well-known Johns Hopkins medical school professor and author said Tuesday.

The study by surgeon and Johns Hopkins professor Martin Makary is the second to report the mistakes represent the third-leading cause of deaths in the U.S.

Death certificates in this country don't have a place for hospitals to acknowledge medical error, which the authors say shows reporting needs to be improved so the problem can be better estimated and addressed.

Death certificates in the United States, Canada, Great Britain and more than 100 other countries rely on what's known as International Classification of Disease (ICD) code, so human and system errors can't be recorded, according to the World Health Organization.

"People don’t just die from billing codes," said Makary, author of the 2013 book Unaccountable: What Hospitals Won't Tell You and How Transparency Can Revolutionize Health Care. "We do not have an open and honest way of measuring medical error."

Death certificates should include an additional form field where it could be noted whether patients' deaths stem directly from care they received and what type of problem it was.

Makary and co-author Michael Daniel wrote that strategies to reduce death from medical care should include making errors "more visible" when they occur, having remedies available to "rescue patients," and making errors less frequent by following principles that take "human limitations" into account.

Calculating how many mistakes in hospitals actually caused deaths has been the subject of debate since the National Academy of Science's Institute of Medicine first estimated in 1999 that up to 98,000 are attributable to medical mistakes.

In 2010, the Department of Health and Human Services' inspector general reported that up to 180,000 Medicare patients alone died a year from medical errors.

John James, a NASA toxicologist whose son died of what he believes was a hospital error, did the last report on the subject in 2013 and estimated between 210,000 and 440,000 deaths a year could be attributed to medical error.

Among the problems associated with calculating medical errors is that some are errors of omission rather than commission, James said in an interview Monday. Others include the fact that people are typically in hospitals because they aren't well, which means several factors can lead to death.

James would know. His son died at age 19 in 2003 after he collapsed while running, because his potassium was depleted. No one at the hospital where he was treated replaced his potassium, as a guideline said they should. James blames a series of medical errors — of omission, diagnostics and communication.

Makary says medical and legal protections are needed, as with hospital quality information, so causes of death are accurately reported. Doctors and others may not acknowledge mistakes for fear of malpractice suits, he says.

It's complicated, says James, adding, "I don't know what the right answer is."