Medicine has become so narrowly specialised that clinicians focused on a single organ system are losing the ability to diagnose outside their core area, it has been claimed.
The inability to make a broad differential diagnosis in the face of uncertainty is becoming a real concern in an era when patients are becoming older and have more co-morbidities, argues Associate Professor of Medicine Ian Scott in an opinion piece for the MJA.
Single-domain specialists tend to be less experienced and skilled than generalists at managing the diagnostic pathway for patients presenting with complex problems and co-morbidities, writes Professor Scott, Director of the Department of Internal Medicine and Clinical Epidemiology at Princess Alexandra Hospital in Brisbane.
“Clinicians trained as generalists seem better at navigating this complex mixture of issues than single content domain specialists. Lack of experience in diagnosing and managing such patients may explain more cross-referrals to other specialists, longer stays and higher resource use incurred by single domain specialists compared with generalists within hospital settings,” he says
Single-domain specialists are prone to generating diagnostic hypotheses relevant to their own specialty, even though a diagnosis outside it may be equally or more valid, he says.
Other forms of cognitive bias such as premature closure compound the problem, he writes, pointing to one study which found that half of all patient-initiated second opinion requests to specialists related to diagnosis and of these, 15% involved a change in diagnosis.
“Further, when diagnostic errors made by one doctor are recognised by other doctors who subsequently see the patient, such errors are rarely communicated back to the original doctor for fear of endangering professional relationships”, he writes.
Evidence also suggests patients under a single-domain specialist may be left undertreated for a second disorder unrelated to their primary condition, he notes.
If the condition remains undiagnosed, the specialist may opt for a “best guess” as to which organ system is affected in order to make a cross referral, writes Professor Scott.
As a flow on effect, diagnostic uncertainty can lead to patients becoming caught in a ‘pass the parcel’ sequence of referrals.
“Each consecutive consultation carries the risk of each different specialist overestimating the predictive value of symptoms and signs as portending serious conditions related to their specialty, which may lead to over-ordering and over-interpretation of diagnostic tests.”
“Given that specialists now outnumber GPs there may be a need to be a commensurate step back from (over) specialisation to generalism, in recognition that of the fact that diagnostic acumen in the face of increasing complexity is a specialisation in its own right,” he argues.
When it comes to enhancing diagnostic skills outside of the narrow domain, Professor Scott points to the example of the 15% of physician trainees who are currently undertaking dual training in a specialty beyond their core interest.
Theres is also a need for specialists to receive feedback on their diagnoses, he adds.
“Health care is moving from a disease-centred model towards a patient-centred model, and this will increasingly blur the boundaries and accountabilities between the different specialties in regards to diagnostic expertise applied to patients with multimorbidity.
“Greater interspecialty communication and more continuous oversight of the care of individual patients by GPs and specialists with generalist training will be required in minimising diagnostic error,” he concludes.