A high percentage of medical errors taking place in non-emergency settings—ranging from a physician’s office to a radiology lab—cause serious harm and death to patients, according to a study by researchers from Brigham and Women’s Hospital, Harvard School of Public Health (HSPH), and the University of Texas Health Science Center.

The report, published Tuesday in Annals of Internal Medicine, found that 30 percent of missed, late, or wrong diagnoses resulted in death, and over 50 percent of the medical errors happened in cancer cases.

Though medical errors are an oft-studied subject, the researchers studied 307 medical malpractice claims that involved errors in an “ambulatory,” or non-emergency, setting—an area that “has been understudied,” according to co-author of the report, Eric J. Thomas, a professor at the University of Texas Health Science Center.

The study examined the different causes of diagnostic errors and categorized the resulting degree of harm to patients by five categories, ranging from emotional trauma to major physical injury to death.

The report concluded that breakdowns occurred at multiple points in the diagnostic process, resulting in a missed or delayed diagnosis.

In many missed diagnoses, two or more physicians contributed to the mistake.

Co-author of the report and an Associate Professor of Law and Public Health at HSPH professor, David M. Studdert said that “cognitive errors play a large role” in these types of medical errors.

The study also recommended ways to improve the diagnostic process, suggesting that systems reducing reliance on doctor’s memory, such as electronic test result tracking systems, be implemented.

Studdert also said that, in certain situations, physicians should consider consulting a specialist in a relevant field to assist with a diagnosis.

While a patient’s wellness is primarily the doctor’s responsibility, “the patient’s role is critical,” Studdert added. Patients should be “active participants” in the diagnostic process.

“People should try and follow up their lab results” to make sure their tests are executed and properly evaluated, according to Thomas.