The story of a family devastated by two separate mistakes in diagnosis within five years highlights that numerous gaps exist in the diagnostic system for patients to fall through, often with truly tragic results.

When Susan S.’s son was born in 1995, he had jaundice, which is a red flag for the possibility of kernicterus, a severe neurological disorder. Despite repeated attempts to alert doctors and health care professionals, the newborn’s diagnosis and treatment were delayed. As a result, he developed cerebral palsy and a number of other neurological problems.

In 1999, a mass was discovered in the cervical section of Susan’s husband’s spine. They were told it was benign, and he underwent surgery to remove it. Six months later he required a second surgery, and this time doctors said the tumor was malignant. It was later discovered that a pathologist reported the tumor was cancerous shortly after the first surgery, but the report had not made it to her husband’s neurosurgeon.

“It was a double whammy, and it made me realize how very, very fragile our health care system is,” says Susan, who is now co-founder and president of a Chicago-based patient advocacy organization called Consumers Advancing Patient Safety.

Approximately 40 percent of medical malpractice lawsuits involve diagnostic errors — failure to diagnose, misdiagnosis or delayed diagnosis. Nearly one in every three adverse events reported involves a diagnostic error, and ten percent of those mistakes result in the wrongful death of a patient. In fact, diagnostic errors result in between 40,000 and 80,000 hospital deaths every year in the U.S., according to researchers.

In this two-part series, we will discuss the underlying causes of avoidable diagnostic errors and the ideas researchers believe could help reduce them.

Doctors Jump to Conclusions About Diagnoses for Identifiable Psychological Reasons

Hardeep Singh, MD, MPH, program chief of the Health Policy and Quality Program at the Houston Veterans Affairs Health Services Research and Development Center of Excellence, says that there are many opportunities for mistakes that can lead to mistakes in diagnosis, given the fragmented nature of the health system.

Cognitive mistakes by diagnosticians account for about a third of diagnostic errors, according to an analysis by the Archives of Internal Medicine. Cognitive errors are biases in a physician’s thinking due to mental shortcuts we all take when thinking through difficult problems. Some examples include:

• Anchoring bias: Locking on to an initial diagnosis and failing to adjust when later information indicates something else
• Confirmation bias: Looking for evidence to support an expected diagnosis and failing to notice evidence that contradicts it
• Overconfidence bias: Acting on incomplete information, intuition or hunches because we believe we know more than we do

“It’s possible that if one were continually vigilant and kept in mind that we tend to be overconfident, one could minimize the fact of these biases, but people just can’t be that vigilant,” said Dr. Arthur S. Elstein of the University of Illinois College of Medicine and a pioneer in psychological research on diagnostic errors.

“You get distracted. If you’ve got five patients in the waiting room, well, you’ve got to get through the day.”

Source: American Medical News, “Diagnostic errors: Why they happen,” Kevin B. O’Reilly, December 13, 2010