More than 1 in 10 patients are harmed in the course of their medical care, and half of those injuries are preventable. Among the preventable errors, 12 percent led to a patient’s permanent disability or death, according to the report published Wednesday in The BMJ, a medical journal.

The study, which included information on more than 300,000 patients from 70 earlier reports, highlights how serious the problem is, said the study’s lead author, Maria Panagioti, a senior lecturer at the University of Manchester.

“We need strategies in place to detect and correct the key causes of patient harm in health care,” Panagioti said in an email. “Our study finds that most harm relates to medication, and this is one core area that preventative strategies could focus on.”

While the study was international in scope, the findings would be applicable to the U.S., Panagioti said.

The new findings come two decades after a jarring report from the Institute of Medicine concluded that medical errors resulted in the deaths of as many as 98,000 Americans each year.

“It’s a reminder that 20 years into our realization about the problems with patient safety, the rate of preventable harm caused by health care continues to be unacceptably high, causing a huge burden of unnecessary patient suffering and even death,” said Dr. Albert Wu, an internist and professor of health policy and management at the Johns Hopkins Bloomberg School of Public Health, who was not involved in the new research.

“This is one of the largest studies ever conducted on the frequency and severity of patient harm,” Wu said. “And it provides evidence that these harms occur in all medical care settings. It’s a problem that needs our attention.”

For the new study, Panagioti and her colleagues combed through the medical literature looking for studies that examined medical errors and patient harms. They settled on 70 studies that contained information on 337,025 mostly adult patients, 28,150 of whom experienced harmful incidents, of which 15,419 were preventable.

While 49 percent of the harms reported in the study were “mild,” 36 percent were considered to be “moderate,” and 12 percent “severe.”

Incidents relating to drugs and other therapies accounted for 49 percent of the harms, and injuries related to surgical procedures accounted for 23 percent. Health care infections and problems arising from diagnoses each accounted for 16 percent of the harms.

There’s no “silver bullet” for reducing medical errors, experts say. It requires a combination of patient and staff engagement, consistent management focus and, sometimes, technology, said Tami Minnier, chief quality officer of UPMC, Pittsburgh.

In 2005, UPMC established “Condition H” — for Help — so patients and families could call for a rapid response team to the bedside for any care concerns, including communication breakdowns, Minnier told NBC News. "While infrequently used, we believe that Condition H has averted significant patient harm over the years," she said.

Other hospitals have made changes in hopes of diminishing the numbers of errors and harms, said Dr. Karl Bilimoria, director of surgical outcomes and quality improvement at Northwestern University’s Feinberg School of Medicine.

"For example, registries have been created to measure harms of various kinds and to allow hospitals to compare themselves to other institutions," Bilimoria said.

When possible, patients and their families can protect against medical errors by becoming their own advocates.

“The more people observing and participating in the patient’s medical care the better,” Bilimoria said. “I would encourage patients to ask physicians to explain things and make sure all have a common understanding.”

Don’t be intimidated by busy doctors or other medical staff, advised Minnier.

“There are some basic things to keep track of,” she said. For example, “make sure they are washing their hands to prevent infections and are using the right protective equipment.”

If you’re not comfortable with what’s happening, “make them pause so you can ask questions,” Minnier said. “Checklists have become very popular. One of the important purposes of checklists is that they force people to pause and think about what is happening.”