To the Editor:
In their Perspective, Norman and colleagues1 contest the relative contribution of cognitive bias to medical error, and they challenge the efficacy of debiasing strategies in mitigating such error. They argue that “knowledge deficits,” rather than cognitive biases, underlie medical error.1 I would like to address key elements of their argument.
What Norman and colleagues include under the rubric of “knowledge” is unclear. Is it factual knowledge, or does “knowledge” also include cognitive attributes acquired through years of experience? They insist that “more experience will lead to greater knowledge.”1 But knowledge gained through experience may be different than the factual knowledge that rectifies “knowledge deficits.” Physicians’ factual “knowledge” base is arguably greatest shortly after they complete their fellowship and board exams, whereas their clinical “experience” is limited at this early stage. If “knowledge deficits” underlie most medical errors, then the most knowledgeable physicians should make the fewest errors. Evidence for such a claim is scant.2 “Experience,” conversely, encompasses the gradual acquisition of complex skills and attributes, such as the capacity to monitor and regulate one’s thinking (metacognition), which can play a critical role in catching and preventing errors before they occur.
In an experimental investigation, Norman and colleagues used hypothetical case vignettes to contest the effectiveness of cognitive debiasing strategies.3 Many physicians would argue that experimental conditions of short duration do not adequately reflect the clinical environments in which complex decision making, leading to medical error, occurs. Debiasing strategies are, however, difficult to test reliably under general experimental conditions, as they may need to be customized to specific contexts and require multiple interventions and sustained maintenance to demonstrate effectiveness.2 Debiasing strategies that are generally underappreciated include metacognitive skills, reflection, feedback, mindful attention, and checklists.
Norman and colleagues’ studies ostensibly demonstrating that physicians are unable to correctly identify cognitive biases are indicative of the lack of awareness and education among physicians about bias, rather than disproving the existence of such biases.
Norman and colleagues are nonetheless right to criticize the assumption that “relatively simple and quick strategies directed at identifying and eliminating biases can reduce errors … [or] that a magic bullet will emerge to eliminate all errors.”1 But this has never been the assumption of Croskerry2 and others who believe cognitive bias is real and debiasing strategies feasible. The debate about cognitive bias has not been settled. It is counterproductive to discourage much-needed ongoing investigation on this critically important topic.
Quentin Eichbaum, MD, PhD, MPH, MFA, MMHC
Professor of pathology, microbiology, and immunology; professor of medical education and administration; director, Vanderbilt Pathology Education Research Group; director, Vanderbilt Pathology Program in Global Health; and clinical fellowship director, Vanderbilt University Medical Center, Nashville, Tennessee; firstname.lastname@example.org.
1. Norman GR, Monteiro SD, Sherbino J, Ilgen JS, Schmidt HG, Mamede S. The causes of errors in clinical reasoning: Cognitive biases, knowledge deficits, and dual process thinking. Acad Med. 2017;92:23–30.
2. Croskerry P. From mindless to mindful practice—Cognitive bias and clinical decision making. N Engl J Med. 2013;368:2445–2448.
3. Zwaan L, Monteiro S, Sherbino J, Ilgen J, Howey B, Norman G. Is bias in the eye of the beholder? A vignette study to assess recognition of cognitive biases in clinical case workups. BMJ Qual Saf. 2017;26:104–110.