Frequently Asked Questions

What do we know about diagnostic error?

All told, diagnostic errors affect an estimated 12 million Americans each year, and likely cause more harm to patients than all other medical errors combined. Missed diagnoses also lead to higher healthcare costs—through treatment of sicker patients with more advanced disease; by overuse of unnecessary, expensive diagnostic tests; as a consequence of malpractice claims; and with the high costs of treatments for diseases patients do not actually have. Some have estimated that $100 billion or more may be wasted annually in the U.S. as a result of inaccurate diagnosis.

How often does it happen?

The National Academy estimates that all of us will experience a diagnostic error in our lifetime, some with devastating consequences.

How often does diagnostic error lead to adverse events and death?

Diagnostic errors affect an estimated 12 million Americans, and likely cause more harm to patients than all other medical errors combined. An estimated 40,000 to 80,000 people die each year from diagnostic failures in U.S. hospitals alone, and probably at least that many suffer permanent disability. The total across all clinical settings is likely much higher.

What is the cause of diagnostic error?

Diagnosis involves both human and system elements. The explosive growth in medical evidence and new technologies ends up being a double-edged sword, making diagnosis more accurate but also more complex at the same time.

From a human perspective, physicians are subject to the same cognitive limitations and biases that affect us all in our day-to-day lives. In medicine today, the complexity is astounding. There are more than 10,000 known diseases and more than 5,000 laboratory tests, but only a small number of symptoms in comparison. So, any one symptom may have dozens, if not hundreds, of possible causes and test options.

Healthcare systems link together hundreds or thousands of different processes, practices, procedures, and technologies. While these systems are built with patient safety in mind, the sheer number of connections increases the risk of miscommunication and other breakdowns along the way.

Is diagnostic error more closely associated with some specialties than others?

Yes, but it is a significant factor for malpractice claims across all specialties. It is the number one cause of claims in primary care disciplines, emergency medicine, radiology, and most of the medical sub-specialties. It is also the number one cause of claims in surgical specialties. Misdiagnosis is most common in primary care and emergency medicine, partly because there are so many visits to these settings, but also because patients are seen early on in an evolving disease process (when their symptoms may be less obvious and underlying diseases harder to diagnose).

Do rare diagnoses account for the majority of diagnostic errors?

No. In fact, three major disease categories—vascular events, infections, and cancer—account for roughly three-fourths of all disability and deaths due to diagnostic failures. Rare diseases are certainly misdiagnosed and can lead to long diagnostic journeys for patients, but misdiagnosis of more common diseases like stroke, sepsis, and lung cancer impacts many more patients. More needs to be done to improve the diagnostic process and reduce errors.

What are the obstacles to accurate diagnosis?

In 2018 SIDM launched ACT for Better Diagnosis, an initiative that identified obstacles to accurate and timely diagnosis. As part of that effort, the Coalition to Improve Diagnosis, made up of more than 50 leading healthcare and patient advocacy organizations identified several obstacles they believe impede diagnostic accuracy, including:

  • Incomplete communication during care transitions—When patients are transferred between facilities, physicians, or departments, there is potential for important information to slip through the cracks.
  • Lack of measures and feedback—Unlike many other patient safety issues, there are no standardized measures for hospitals, health systems, or physicians to understand their performance in the diagnostic process, to guide improvement efforts, or to report diagnostic errors. Providers rarely get feedback if a diagnosis was incorrect or changed.
  • Limited support to help with clinical reasoning—With hundreds of potential explanations for any one particular symptom, clinicians need timely, efficient access to tools and resources to assist in making diagnoses.
  • Limited time—Patients and their care providers overwhelmingly report feeling rushed by limited appointment times, which poses real risks to gathering a complete history that is essential to formulating a working diagnosis and allows scant opportunity to thoroughly discuss any further steps in the diagnostic process and set appropriate expectations.
  • The diagnostic process is complicated—There is limited information available to patients about the questions to ask, whom to notify when changes in their condition occur, or what constitutes serious symptoms. It’s also unclear who is responsible for closing the loop on test results and referrals, and how to communicate follow-up.
  • Lack of funding for research—The impact of inaccurate or delayed diagnoses on healthcare costs and patient harm has not been clearly articulated, and there is a limited amount of published evidence to identify what improves the diagnostic process.

What can be done to reduce diagnostic error and harm?

The Society to Improve Diagnosis in Medicine (SIDM) envisions a world where no patients are harmed by diagnostic error. SIDM recognizes that everyone has a role to play in improving diagnosis, including health systems, physicians, nurses, radiologists, laboratory physicians and scientists, patients and others. Our strategic priorities include:

  • Making improving diagnosis a strategic priority for healthcare at the practice, system, and policy levels.
  • Advancing research on diagnostic accuracy and error that will lead to reduced harm.
  • Transforming our nation’s medical education system to teach aspiring physicians and others what they need to know about both obstacles to accurate and timely diagnosis and potential solutions.
  • Improving diagnostic performance in clinical practice through greater engagement of patients, clinicians, and other healthcare professionals.
  • Ensuring that the voices of patients and their families are heard in all diagnostic improvement efforts.
Doctor Talking to Patient
Patient Safety Imperative

Patients and family members have a significant opportunity to contribute to diagnostic accuracy and timeliness by actively participating in the diagnostic process.

Reducing Diagnostic Error and Improving Patient Safety