One in four hospital patients suffers adverse events, and some can be avoided

Researchers found about a quarter of adverse events are preventable, according to a new study. But many hospitals rely on voluntary reporting, so some adverse events likely aren't being captured.

Patients suffer an adverse event in nearly one out of four hospital admissions, pointing to a need to improve patient safety, researchers say.

Among those adverse events, nearly a quarter were judged to be preventable, according to the study published Wednesday in the New England Journal of Medicine.

“These findings underscore the importance of patient safety and the need for continuing improvement,” the authors wrote.

Researchers examined admissions at 11 Massachusetts hospitals during 2018, so the study period came before the COVID-19 pandemic. Federal officials have said patient safety has suffered during the pandemic, as evidenced by increases in hospital-based infections.

Adverse drug events were the most common type of adverse events (39%), followed by events related to surgeries or other procedures (30.4%); patient care events, such as falls or pressure ulcers (15%); and healthcare-associated infections (11.9%), researchers found.

Researchers examined a random sample of 2,809 admissions and found at least one adverse event in 23.6% of the admissions.

Among the 978 adverse events, researchers identified nearly a quarter (22.7%) as preventable. A preventable adverse event occurred in 191 admissions (6.8% of all the admissions studied).

The researchers said nearly a third (32.3%) caused harm that required “substantial intervention or prolonged recovery,” the researchers noted. There were seven deaths, and one death was deemed to be preventable, according to the study.

Dr. David Bates, the chief of general medicine at Brigham and Women’s Hospital and the medical director of clinical and quality analysis for Mass General Brigham in Boston, was the lead author of the study. He talked about the findings with NBC News.

“These numbers are disappointing, but not shocking,” Bates told NBC. “They do show we still have lots of work to do.”

While the numbers underscore the need to improve patient safety, hospitals may not be capturing the full scope of events that are harming patients, the researchers acknowledged.

“Even today, many U.S. hospitals rely solely on voluntary reporting of adverse events, which results in substantial undercounting and, in some cases, misleading reports of zero harm,” the authors wrote.

The researchers noted that it’s easy to measure some problems, such as infections, but it’s more difficult to track adverse drug events. The authors noted the fluctuations over time is unclear, since “hospitals do not routinely measure the frequency of such events.” Adverse drug events likely occur more often than voluntary reporting indicates, they wrote.

In the future, adverse events in electronic health records will be analyzed more closely by automated triggers and artificial intelligence, the researchers wrote. While some tools identify adverse drug events and hospital-associated infections, the authors suggested that it’s time to expand the harms assessed by those tools.

The researchers examined admissions from large and small hospitals. Three hospitals had more than 700 beds, while two hospitals had less than 100 beds.

The study also mirrors other troubling indicators on patient safety. One in four Medicare patients (25%) experienced harm in a hospital, according to a report issued last year by the U.S. Department of Health and Human Services Office of Inspector General.

In that study, the most common type of harmful event was related to medication, followed by events related to patient care and infections. The inspector general’s study examined Medicare beneficiaries in 2018 and estimated the costs of the harm events reaching hundreds of millions of dollars.

Hospitals had been making significant progress in improving patient safety in the years before the pandemic, Leah Binder, president and CEO of the Leapfrog Group, told Chief Healthcare Executive in a November interview.

“We have some cautious optimism. We think as a country we might be on the right track in addressing patient safety effectively,” Binder said. “We haven’t gotten there. There’s a lot more work to do.”

Health systems must make patient safety a greater area of focus, the researchers in the NEJM study suggested.

“Other key organizational elements such as safety culture and strong leadership with respect to safety and quality are also needed to advance performance,” the authors wrote. “Our findings are an urgent reminder to all health care professionals of the need for continuing improvement in the safety of the care we deliver.”