Patients’ Skepticism About Medical Treatment Is Warranted

Dr. Vinita Parkash, professor of pathology at Yale School of Medicine, recently wrote a commentary featured in WBUR-Boston’s opinion section, Cognoscenti. In the commentary, she recalls a mistake she made earlier in her career: She failed to identify cancer cells when examining a tissue sample from a 42-year-old woman. That woman later died of cancer.

Parkash notes that diagnostic errors receive less attention than other types of medical errors, such as surgical devices left inside patients, or medication mistakes. But diagnostic errors account for between 40,000 and 80,000 deaths per year. The challenge in understanding how to prevent diagnostic errors is that many doctors do not report their mistakes; therefore, no one else can learn from their experience.

Why Diagnostic Errors Occur

A diagnosis that is missed, incorrect, or delayed is considered a “diagnostic error.” An incorrect diagnosis may lead doctors to prescribe unnecessary and harmful medication or procedures. A missed or delayed diagnosis – especially with progressive illnesses like cancer – could lead to a patient’s death.

Diagnostic errors may occur for a multitude of reasons, such as:

  • Lack of awareness regarding patient’s background – Doctors must ask good questions to help them identify possible causes of symptoms. For example, if an older person complains of shortness of breath and is a life-long smoker, doctors may order tests to look for cancer and emphysema.
  • Failing to consider unusual causes – Some diseases are uncommon, and when attempting to diagnose a patient, doctors may fail to consider illnesses that are considered “rare.”
  • Confirmation bias/anchoring – When, based on a few symptoms, doctors make a quick diagnosis, they may be more inclined to ignore symptoms that don’t fit the assumption they’ve made.
  • Rushing – Many family physicians today see patients for only 15 minutes at a time. Feeling pressure to resolve every patient’s illness, doctors may rush to diagnosis, without taking time to order additional tests.
  • Failing to rule out other conditions – When a symptom could be caused by two (or more) similar illnesses or conditions, confirming that one illness exists isn’t enough. Doctors should also rule out other conditions, to ensure that patients are not suffering from multiple illnesses.
  • Miscommunication – Diagnostic test results may change hands many times in a healthcare setting. Those results could be incorrectly communicated among staff or be improperly logged.

Prevalence of Errors Could Be Much Higher

Researchers at Johns Hopkins University in 2013 released a report on diagnostic errors in the medical profession. The research team found that of all medical errors, diagnostic errors caused the most severe harm to patients and accounted for the largest proportion of malpractice claims. Between 1986 and 2010, malpractice payouts for diagnostic errors amounted to $38.8 billion.

Researchers noted that their study included only diagnostic errors that resulted in malpractice claims and that the actual number of patients who suffer “significant permanent injury” or death from diagnostic errors could be between 80,000 and 160,000. Some incorrect, missed, or delayed diagnoses are likely never discovered, as patients may die of presumably natural causes, without ever knowing they had an underlying disease or condition.