More than 1 in 3 surgical patients has complications, study finds, and many are the result of medical errors

Despite decades of calls for more attention to patient safety in hospitals, people undergoing surgery still have high rates of complications and medical errors, a new study finds.

More than a third of patients admitted to the hospital for surgery have adverse events related to their care, and at least 1 in 5 of these complications is the result of medical errors, the researchers found.

Studies delving into adverse events and medical errors in hospital settings are few and far between, and each has slightly different methods, so their results aren't always an apples-to-apples comparison. But the latest study , which was published Thursday in the BMJ, fits into a pattern of evidence going back decades, suggesting that hospitals haven't made much progress on patient safety.

"It's pretty disturbing," said Helen Haskell, an expert who became a reluctant patient safety advocate after her son, Lewis Blackman, died at the age of 15 following complications from surgery to correct a condition called pectus excavatum, or a sunken chest. She wrote an editorial that was published alongside the new study.

A medication her son was given to control pain caused a hole in his digestive tract called a perforated ulcer, which led to internal bleeding, an infection and septic shock. Haskell says she watched as her previously healthy, athletic son deteriorated before her eyes.

"We couldn't get anybody's attention, and he just died. He was in agony for 30 hours, and then he died," she said.

If he had survived, she said, he would now be almost 40, something that's hard to think about.

After his death, Haskell founded the group Mothers Against Medical Error, which promotes patient safety in hospitals.

Haskell says it's frustrating to see continued harm to patients related to the care they receive in hospitals.

"These are longstanding issues that are not really being properly addressed, because I think they're not as high in the consciousness of either patients or health care providers as they should be," she said.

For the new study, a team of researchers based at Harvard University set out to copy the careful methods of the Harvard Medical Practice Study, a study conducted in the 1980s that was one of the first to detail rates of patient harm from health care. Its findings became the basis for a 1999 report from the National Academies of Sciences called "To Err is Human," which sounded the alarm on patient safety problems health care settings.

"We're trying to figure out, have things changed? Have they gotten better?" said Dr. David Bates, a professor of health policy and management at Harvard's T.H. Chan School of Public Health, who led the new research.

Since the original study, there have been important changes in hospitals that are designed to make surgery safer. Electronic medical records can send alerts, for example, if someone is prescribed two medications that might have dangerous interactions. Surgeons also routinely use presurgery checklists, something that wasn't always done four decades ago. There have also been campaigns to make doctors and patients aware of stealthy conditions like sepsis that can quickly turn deadly.

However, the new study found that safety issues persist.

"It's clear that the problem has not gone away. If anything, it's even bigger than it was," Bates said.

Bates says it's hard to directly compare the findings of the older Harvard study to the newer one because so much about health care delivery itself has changed over the past 40 years. For the older study, for example, the researchers combed through paper charts. This time, they used electronic medical records.

Patients are different, too. In many cases, people in hospitals are sicker than they used to be, and procedures have become riskier and more complex, said Dr. Kedar Mate, president and CEO of the nonprofit Institute for Healthcare Improvement, an organization that advocates for patient safety.

Given this higher degree of difficulty, "the fact that our overall adverse event rate is about the same as it was 20 years ago is in some ways an accomplishment, even though the rate of harm is still far too high and far too great," said Mate, who was not involved with the new study.

Akin Demehin, senior director of quality and patient safety at the American Hospital Association, said hospitals and health systems are continuously working to advance patient safety and quality. Demehin pointed to recent data from the US Centers for Disease Control and Prevention that showed a decline in health care-associated infections.

Assessing harm in hospitals The research looked at the outcomes of more than 1,009 people admitted to 11 hospitals in Massachusetts in 2018 for surgery.

The researchers say this was the most recent data they could have analyzed, given how long it took to get all the hospitals to agree to participate (11⁄2 years), collect all the records they needed (2 years), have nurses review the records and identify potential adverse events (1 year). Doctors then spent another four months verifying the events and ruling on whether these problems appeared to be preventable, according to study researcher Dr. Antoine Duclos, who directs the Research on Healthcare Performance Lab at Universite Claude Bernard in Lyon, France.

Of the 1,009 surgical patients, 383 (38%) experienced at least one adverse event. Roughly half of these events – 160 – were judged to be serious or life-threatening, the study says.

More than 250 surgery patients, or about 1 in 4, had at least one adverse even that was deemed to be potentially preventable, while 103, or about 10%, had events that were judged to be definitely preventable or the result of medical errors. By proportion of patients who had adverse events, about 60% were determined to be potentially preventable, and about 20% were ruled to be definitely preventable.

The most common types of complications were related to the surgery itself, followed by medication errors and health care-associated infections.

The risk of a complication increases with the patient's age, the study found, and with the type of procedure they had. Operations involving the heart and lungs had the highest rates of complications, followed by operations on the gut and digestive system, and procedures involving the bones and joints.

These incidents most commonly happened outside the operating room, usually once a patient had returned to their hospital room. They include things like falls and pressure ulcers, Bates said.

Most hospitals have a policy of regularly reviewing cases where patients were harmed with their doctors, but they do that for a tiny fraction of the total, Bates added.

Bates said standard approaches for finding adverse events identify only about 5% cases.

"It's just a lot bigger problem than most hospitals recognize," he said.

Mate agrees. "It is high, and it is terrible, and it should be alarming to everyone in the industry and that is paying attention."

The study has some important limitations. All the hospitals that participated were in Massachusetts, and even though researchers tried to include hospitals of different sizes in different parts of the state, it's not clear whether these results would be the same in other states or regions in the US.

The study authors also limited their focus to patients admitted to the hospital for surgery. They may not apply to other settings, such as outpatient surgery centers, which tend to handle less complex procedures.

The study also relied on electronic medical records, which are prone to errors, the researchers noted.

Still, advocates say the study should put renewed focus on patient safety.

Bates says that reducing surgical complications is a job for hospitals and doctors but that there are things patients can do to lower their risk of complications.

"It's useful, for example, to know what medications you're taking and to keep track of what the dosages are," he said.

It's also a good idea to bring someone with you to the hospital if you're going in for surgery.

"Often, people who are in the hospital are not that mentally alert," Bates said, "They're not their usual self or in pain. And so having someone else, either a friend or a loved one, there can be really helpful."