Diagnostic failure is a major threat to the medical consultation, but there are practical measures that help to mitigate its impact. These are broadly classified into two; the first are cognitive forcing strategies that improve the diagnostic decision-making skills of doctors. The second are strategies which improve the knowledge and expertise of doctors.
Many of the cognitive forcing strategies that reduce diagnostic failure aim to minimise the effect of uncertainty on the diagnostic process. As highlighted by Donald Redelmeier in a paper titled Improving patient care. The cognitive psychology of missed diagnoses, one of the consequences of uncertainty is to set doctors on an ‘unnecessary search for rare diseases or diagnostic zebras, a practice which he said ‘can cloud the obvious’. On the contrary, he advised that rare disorders should only be considered in unusual and complex cases, or when the diagnosis has remained elusive. Similarly, he cautioned against ‘the assumption that a diagnosis must be made at all costs‘, warning that ‘this is often impractical or unnecessary‘. Arguing that ‘time is often a good diagnostic test’, Redelmeier advocated the use of good communication, good follow up‘, the tolerance of uncertainty‘ and sharing uncertainty with patients in place of requesting tests just to pre-empt litigation. Further cautioning against the inordinate pursuit of diagnostic mimics or masquerades, Redelmeier pointedly remarked that ‘the tendency to leave no stone unturned, to tie up all the loose ends, to believe that time is of the essence, belongs more appropriately in the solving of a murder mystery than in medical diagnosis and treatment’.
Another cognitive approach discussed by Eta Berner and Mark Graber in their paper titled Overconfidence as a cause of diagnostic error in medicine is aimed at making doctors better at formulating comprehensive differential diagnoses. They particularly urged doctors to regularly ask themselves ‘what diagnosis can I not afford to miss‘, and to always consider the opposite diagnosis to the one they have made. One method they advocated to force clinicians to consider alternative diagnoses is the practice of prospective hindsight, a method by which doctors imagine ‘a future where their initial diagnosis turns out to be wrong‘.
Reflective practice is another key approach to minimising the risk of diagnostic failure. This was also advocated by Berner and Graber who defined it as ‘the ability of physicians to critically consider their own reasoning and decisions during professional activities’. Arguing that this type of reflection is a proven technique in reducing diagnostic error, they identified 5 components of reflective practice: metacognition (thinking about your thinking); openness toward reflection to improve ‘toleration of uncertainty‘; testing ‘any related predictions against the known facts’; searching for alternative hypotheses in complex and unfamiliar problems; and exploring the consequences of alternative diagnoses.
Silvia Mamede and colleagues also addressed the role of reflective practice in their paper titled Effects of reflective practice on the accuracy of medical diagnoses. They compiled a checklist of 11 reflective practice items which they said helps to improve the accuracy of diagnoses. These items included re-reading the case; listing the findings that support and oppose the primary diagnosis; listing alternative hypotheses if the first hypothesis proves to be incorrect; listing the findings that support and oppose the alternative hypothesis; ranking the diagnostic hypotheses in order of likelihood; and then presenting a final diagnosis.
Another major strategy for reducing diagnostic error is the use of clinical decision support systems to overcome the limitations of human cognitive capacity. In his commentary titled Physician self-examination, Lucian Leape strongly recommended the use of computers to aid the diagnostic process, arguing that they enable ‘the accumulation and dissemination of vast amounts of information‘. Because of this capacity, he said computers help the physician ‘to obtain all the necessary information, to process it efficiently, to consider all alternatives, and to make the right decisions‘. Robert Wachter also recommended the use of clinical support systems in his article titled Why diagnostic errors don’t get any respect – and what can be done about them.
Another effective technique of minimising the risk of diagnostic failure is to enlarge the circle of practitioners making the diagnosis. A typical example of this is the seeking of second opinions as advocated by Berner and Garber. John Scarpello also discussed other ways of minimising the inherent risks of a single person making the diagnosis in his article titled Diagnostic error: the Achilles’ heel of patient safety? The strategies he advocated included the early review of patients by more experienced clinicians, open cross-specialty review of cases, multidisciplinary team meetings for clinical decision-making, and sharing responsibility for the care of patients.
Amongst the other recommendations for reducing diagnostic error are the use of comparative thinking, advocated by Thomas Mussweiler and Ann-Christin Posten in their paper titled Relatively certain! Comparative thinking reduces uncertainty, and the use of enhanced follow-up, suggested by Tejal Gandhi and colleagues in their paper titled Missed and delayed diagnoses in the ambulatory setting: a study of closed malpractice claims.
In the next blog we will look at the second strategy for minimising the risk of diagnostic failure – the nurturing of clinical expertise.