Diagnostic Error

Dx errors are the most costly allegations, and nearly half involve high-severity harm.

Despite being ranked third in total cases, diagnostic (Dx) error claims are number one in cost, based on total percentage of cost. These claims account for 24% of all claim costs. The largest percentage (43%) of Dx error claims originate from care provided in the outpatient clinic setting. The second largest percentage (34%) of Dx error claims originate from care provided in the inpatient hospital setting. The remaining claims (23%) occur in the emergency department (ED). Also, a substantial 49% of all Dx error claims involve high-severity harm such as death and long-term disability. In the outpatient clinic setting, the majority of Dx error claims involve problems in the initial diagnostic assessment stage (60%), which can happen when differential diagnoses are not considered or tests aren’t ordered to help determine diagnosis. Many other Dx errors occur during follow-up and coordination of care (46%), where communication breakdowns within the care team or failure to refer to a specialist can lead to patient harm. The remainder of Dx errors in the outpatient clinic setting occur in the tests and results processing stage (20%), where various misinterpretations or errors can occur. A claim may have, and often does have, multiple breakdowns in care processes. In the ED, most Dx error claims involve problems during the initial diagnostic assessment (83%), and almost half also have problems with follow-up and coordination—similar to the outpatient clinic setting, as mentioned above. With a significant number of claims in the outpatient and ED settings involving follow-up system failures, Constellation’s analysis reveals that accurate and timely diagnosis depends nearly as much on systems and the health care team as it does on the diagnosticians themselves.

Dx errors in the outpatient clinic setting account for 42% of claims, making them the top in cost in this setting at a total of $49 million.

Claims in the Emergency Department Setting
In the emergency department (ED), Dx error claims account for nearly 46% of all ED allegations.
The diagnoses that are most-missed in the ED are vascular (32% of claims), fracture or dislocation (18%) and infection (16%).

Dx errors are involved in nearly half
of all ED allegations that result in claims.

Case by Case

Lead contributing factors in Dx claims, during the three stages of the Dx process of care are:

Patient assessment:
• Failure/delay in ordering a test
• Failure to appreciate or recognize signs/symptoms/ test results
• Narrow diagnostic focus by failing to establish a robust differential diagnosis list
• Failure to respond to repeated patient concerns/symptoms
Testing and results processing:
• Misinterpretation of diagnostic studies
Follow-up and coordination:
• Failure/delay in consult/referral
• Breakdowns in communication among care team members about the patient’s condition

Constellation leveraged CRICO’s Diagnostic Process of Care Framework to map where clinic diagnostic breakdowns most commonly occurred along the process of care.

Case 1

Lead contributing factors in Dx claims, during the three stages of the Dx process of care are:

A 37-year-old woman was examined by her gynecologist for an annual exam. She was breastfeeding her almost one-year-old child at the time. She complained of a painful lump in her right breast. The physician’s exam findings found the breasts to be normal and stated the painful breast lump was likely due to breastfeeding. The woman was instructed to return for a follow-up exam when she finished breastfeeding. One and a half years later, she presented with a complaint of a right breast lump that she described as chronic. She was still breastfeeding. Upon exam, the physician noted a small mobile mass on the right breast and referred her for an ultrasound, which revealed a 1.5 cm irregular mass suspicious for malignancy and a 7 mm round mass suspicious for malignancy. Ultrasound-guided biopsies of both masses revealed invasive ductal carcinoma. She received chemotherapy and had a bilateral mastectomy. The woman filed a malpractice claim alleging an 18-month delay in diagnosis, reducing her chances of survival. Experts who reviewed the care were critical of the follow-up instructions because they were not clear about the timing for follow-up examination. The case was closed with a payment to the patient on behalf of the gynecologist.

These contributing factors played a role in the allegation of Dx error:

Failure to appreciate or recognize signs/symptoms/ test results

Narrow diagnostic focus by failing to establish a robust differential diagnosis list

Failure to order test to rule out cancer

Case 2

ED misses diagnosis of vertebral aneurysm.

A 60-year-old woman presented to the ED with a complaint of sudden onset bilateral neck pain that began four days prior without any trauma. She also complained that she had dizziness and a headache that had since resolved. She rated her pain as a 9/10, described it as shooting pain up the sides of her neck and indicated that turning her head from side-to-side worsened the pain. The physician examined her and noted her spine and neck were nontender and that she had pain with side-to-side turning of her head. He diagnosed neck muscle spasm and prescribed tramadol. The next day, the woman presented to another ED with complaints of continued neck pain and a headache. The ED clinician heard a right carotid artery bruit and noted meningismus. He performed a lumbar puncture (LP) to rule out meningitis. During the LP, her cerebral spinal fluid returned bloody and did not clear. Shortly after the LP, the woman had seizure-like activity and became unresponsive.
She was intubated and a CT demonstrated a subarachnoid hemorrhage. She was transferred to a tertiary center where a large intracranial aneurysm arising from the distal vertebral artery was diagnosed. A neurosurgeon performed a coil intracranial embolization but unfortunately the woman remained unresponsive in the ICU for two weeks following surgery. Her family elected comfort care until she died a week later.
Her family filed a malpractice claim against the first ED physician and hospital alleging failure to diagnose and timely treat a vertebral aneurysm. The experts who reviewed the case were critical of the ED physician for failing to do a thorough exam and ruling out a vascular or neurologic cause of the woman’s sudden onset head and neck pain.

These contributing factors played a role in the allegation of Dx error:

Narrow diagnosis focus by failing to establish a robust differential diagnosis list

Failure/delay in ordering a test to rule out a serious condition

Constellation/SIDM Collaborative
Last July, Constellation and the Society to Improve Diagnosis in Medicine (SIDM) launched a quality improvement (QI) Collaborative focused on improving the diagnostic process during two of the three key stages of the diagnostic process of care: (1) test and results processing, and (2) follow-up and coordination.

The Collaborative was a virtual community where participants shared their QI work, raised questions, received consultative support and engaged in shared learning. Over the course of the year, Collaborative participants worked on a QI project to reduce diagnostic error caused by follow-up system failures in their organization.

Watch the Webinar
Our on-demand June 2022 webinar about what was learned during the Constellation/SIDM Collaborative on Dx error.

Red Our Blog Article
Read about challenges, barriers and lessons learned in year one of the Constellation/SIDM Collaborative on Dx error