Diagnostic overshadowing among people with mental illness: views and experiences of emergency department staff

Background/Objectives: One factor suggested to contribute to the health inequalities suffered by people with mental illness is discrimination by health care professionals. One form of this discrimination has been described as ‘diagnostic overshadowing’. This refers to the process by which a person with a mental illness receives inadequate or delayed treatment due to the misattribution of their physical symptoms to their mental illness. The concept of diagnostic overshadowing as it affects people with learning disabilities has been investigated over the past 20 years but has only recently received attention as a phenomenon occurring in people with mental illness. One recent study identified attitudes of treatment staff and diagnostic overshadowing as two areas of concern among mental health service users, who reported feeling „labelled and triaged as ‘psychiatric’ regardless of their presenting complaint“. It is important to explore clinicians’ perspectives of this phenomenon so that training or other interventions can be developed. After we were unable to find any literature on clinician perspectives on diagnostic overshadowing, we undertook a qualitative study of emergency department clinicians at a local hospital. Our aim was to explore their views and experiences regarding diagnostic overshadowing: what factors made it more and less likely to occur; its frequency; and what might be done to reduce the likelihood and rate of its occurrence.

Methods: We conducted individual in-depth interviews on barriers and facilitators to a diagnosis of physical illness in people with severe mental illness in the emergency department. Interviews were audio recorded, transcribed and subjected to thematic analysis using NVivo software. We then conducted a focus group of participants to review and validate the results of the qualitative analysis of the one-to-one interviews.

Results: Twenty-five emergency department staff took part: 15 nurses (including those involved in triage and management), 8 doctors, and 2 nurse practitioners. Diagnostic overshadowing was described as a significant issue with minor to severe consequences. Estimates of frequency were higher for less severe incidents of diagnostic overshadowing, while severe cases were described as less frequent. Three groups of factors influencing frequency of diagnostic overshadowing were described: (1) patient-clinician interactions, (2) patient-environment factors and (3) clinician-environment interactions.

Discussion/Conclusions: Many participants felt that diagnostic overshadowing was a problem in the context of the emergency department and that there were unique challenges to making a physical illness diagnosis in a patient with a mental illness. Factors that made diagnostic overshadowing more likely included challenges in patient-clinician interactions, and the stressful nature of the emergency department for patients and clinicians. Greater parallel working between psychiatric staff and emergency department staff was described as a change that could address the problem of diagnostic overshadowing.

Funding: This presentation presents independent research commissioned by the National Institute for Health Research (NIHR) under its Programme Grants for Applied Research scheme (grant no. RP-PG-0606–1053). The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health.

Keywords: Discrimination, diagnostic overshadowing, emergency care.