Study: 1 in 20 patients victim of preventable medical error

Say you go in for knee surgery and find the surgeon operated on the wrong leg. Or you received a drug you know you’re allergic to.

Preventable medical mistakes cost about $9.3 billion in extra healthcare costs, according to researchers. File Photo by Tareq Salahuddin/

It happens. In fact, about 1 in 20 patients is a victim of preventable medical errors, and 12 percent of such cases result in permanent disability or death, researchers say.

Most preventable harm is caused by medication and other treatments — 49 percent — and by invasive procedures, the study found.

Preventable medical errors are more common in surgical and intensive care units than in general hospitals, and lowest in obstetric units, said the U.K. researchers. They were led by Maria Panagioti, of the NIHR Greater Manchester Patient Safety Translational Research Center.


Preventable harm results in about $9.3 billion in extra health care costs in the United States, according to the study.

The findings are based on data from 70 observational studies involving more than 337,000 mostly adult patients. Of these, more than 28,000 experienced harmful incidents and more than 15,000 suffered preventable harms.

The findings suggest that reducing preventable patient harm could lead to significant improvements in medical care and considerable cost savings for health care systems worldwide, Panagioti and her colleagues said.


The study affirms “that preventable patient harm is a serious problem across medical care settings,” the researchers wrote. They added that “priority areas are the mitigation of major sources of preventable patient harm [such as drug incidents] and greater focus on advanced medical specialties.”

It’s also important to gather evidence across medical specialties such as primary care and psychiatry, vulnerable patient groups, and developing countries, they added.

The study was published July 17 in the BMJ.

In an accompanying editorial, experts at the London School of Economics and Harvard Medical School said the study “serves as a reminder of the extent to which medical harm is prevalent across health systems, and, importantly, draws attention to how much is potentially preventable.”

The editorialists said the ability to measure preventable harm must be improved. “This includes fostering a culture that allows for more systematic capturing of near misses, identifying harm across multiple care settings and countries, and empowering patients to help ensure a safe and effective health system,” they said in a journal news release.

ByHealthDay News