Risk Management Tools & Resources


Diagnostic Overshadowing and At-Risk Patients

Diagnostic Overshadowing and At-Risk Patients

Laura M. Cascella, MA, CPHRM

Lapses in clinical judgment are a well-established contributing factor in diagnostic errors, and it is widely accepted that cognitive biases are a major cause of these lapses. Numerous types of cognitive biases exist, but certain patients might be particularly susceptible to a bias called diagnostic overshadowing.

Historically, “diagnostic overshadowing” referred to situations in which patients’ psychological or physical symptoms were wrongly attributed to already-diagnosed intellectual disabilities or behavioral health disorders. Now the term more broadly refers to situations in which clinicians misattribute a patient’s signs or symptoms to any known condition the patient has (whether physical, psychological, or cognitive).1

Diagnostic overshadowing can occur with patients of all ages and backgrounds who have a preexisting diagnosis; however, certain individuals are at increased risk, including those who have physical and cognitive disabilities, behavioral health disorders, neurodevelopmental and neurological disorders, obesity, low health literacy, and substance use disorders.2

Diagnostic overshadowing is closely related to other types of cognitive biases, including:

  • Anchoring, which is a tendency to “anchor” to, or rely too much on, a particular piece of information
  • Premature closure, which is the termination of the data-gathering process before all of the information is known
  • Implicit biases and affective influences, which refer to emotions and feelings (e.g., stereotypes) that can sway clinical reasoning and decision-making3

The common factor in all of these biases is the inability to overcome initial interpretations to further explore possible causes of a patient’s symptoms. “Once an initial diagnosis has been made, momentum sometimes takes hold and reduces a clinician’s ability to consider other alternatives.”4 Moreover, diagnostic overshadowing can spread along the continuum of care if it distorts “future patient workups and how handoffs to other providers are framed.”5

Diagnostic overshadowing can result in delayed or missed diagnoses of health conditions and subsequent poor outcomes and patient harm. Patients may suffer unnecessarily when conditions are not promptly diagnosed and treated. They also may lose confidence and trust in their providers and the healthcare system, which can lead to avoidance of care.

Beyond the individual impact, diagnostic overshadowing also can have broader public health implications, such as further stigmatizing certain conditions (particularly disabilities and behavioral health disorders), reinforcing existing health disparities, and perpetuating morbidity and mortality inequities for at-risk patients.

As with other cognitive biases, more research is needed to understand the complexities of diagnostic overshadowing and find effective ways to combat it. However, some helpful strategies for clinicians may include the following:

  • Be knowledgeable about the potential for diagnostic overshadowing and how it can lead to missed or delayed diagnoses. Acknowledging situations in which this bias can occur may help improve overall awareness and understanding.
  • Adopt a team-based approach to strengthen the diagnostic process. Make sure your practice environment is conducive to collaboration and has the technology, structure, and culture in place to support effective communication.
  • Use clinical guidelines, checklists, clinical pathways, evidence-based decision support systems, electronic health record alerts, and other technologies (e.g., trigger algorithms) to support the diagnostic process and team collaboration.
  • Engage patients and their families in the diagnostic process. Clearly explain the process, and encourage patients to provide thorough information about their health and medical histories, ask questions, and follow up on test and laboratory results.
  • Allow adequate time for dialogue, and repeat important information to confirm understanding of the patient’s reason for visiting, their concerns, and their point of view. Make an effort to allow the patient to fully voice their concerns without interruption.
  • Ask patients about what they perceive as barriers to their care and what works best for them in the care setting. Request that they provide feedback on how the practice can do better in the future. Review any feedback with staff to determine strategies for further improving cultural competence.
  • Make a purposeful effort to see each patient as a unique individual (looking beyond their existing conditions or personal characteristics), and respect their values, experiences, preferences, and expressed needs.
  • Update and review patients’ medical histories, problem lists, medication lists, and allergy information at each visit. Make sure patients’ health records reflect their most recent information.
  • Perform complete patient assessments, including establishing differential diagnoses, considering appropriate diagnostic testing, and carefully reviewing test results.
  • Incorporate a diagnostic review process into the workflow pattern. The review might include timeouts to (a) reflect on working diagnoses, (b) seek consultations, and/or (c) facilitate group decision-making to support clinical reasoning.
  • Engage in diligent follow-up when treating patients who have persistent symptoms or conditions that are difficult to resolve. Reconsider differential diagnoses of returning patients and patients who show no signs of improvement.
  • Explore group educational opportunities that allow members of the diagnostic team to better understand cognitive biases and develop solutions together. Learn about various de-biasing techniques, such as situational awareness, metacognition, perspective-taking, emotional regulation, and partnership-building.
  • Consider using structured tools or approaches to identify the types of diagnostic errors occurring in the practice and the root cause of the errors. Use this information to educate the clinical team and develop countermeasures to improve quality of care.

Diagnostic overshadowing is one type of cognitive bias that can lead to diagnostic errors, patient harm, and broader public health implications. As with other types of cognitive errors, diagnostic overshadowing does not have one simple solution. More research is needed on developing effective and feasible strategies to tackle this issue in various practice settings. However, building awareness of the potential risks related to diagnostic overshadowing can help healthcare providers mitigate them through development of policies and procedures, workforce and workflow evaluation, and ongoing training.

For more information about diagnostic overshadowing, see the following resources:


1 Hallyburton A. (2022). Diagnostic overshadowing: An evolutionary concept analysis on the misattribution of physical symptoms to pre-existing psychological illnesses. International Journal of Mental Health Nursing, 31(6), 1360–1372. doi: https://doi.org/10.1111/inm.13034

2 Rader, R., & McGaffigan, P. (2022, July 27). Diagnostic overshadowing worsens health disparities. The Joint Commission. Retrieved from www.jointcommission.org/resources/news-and-multimedia/blogs/advancing-health-care-equity/2022/07/diagnostic-overshadowing-worsens-health-disparities/

3 Hallyburton, Diagnostic overshadowing: An evolutionary concept analysis on the misattribution of physical symptoms to pre-existing psychological illnesses.

4 Rader, et al., Diagnostic overshadowing worsens health disparities.

5 Ibid.

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