Specific Disease Knowledge as Predictor of Susceptibility to Availability Bias in Diagnostic Reasoning: a Randomized Controlled Experiment

Dual process models of clinical reasoning: The central role of knowledge in diagnostic expertise

RATIONALE

Research on diagnostic reasoning has been conducted for fifty years or more. There is growing consensus that there are two distinct processes involved in human diagnostic reasoning: System 1, a rapid retrieval of possible diagnostic hypotheses, largely automatic and based to a large part on experiential knowledge, and System 2, a slower, analytical, conscious application of formal knowledge to arrive at a diagnostic conclusion. However, within this broad framework, controversy and disagreement abound. In particular, many authors have suggested that the root cause of diagnostic errors is cognitive biases originating in System 1 and propose that educating learners about the types of cognitive biases and their impact on diagnosis would have a major influence on error reduction.

AIMS AND OBJECTIVES

In the present paper, we take issue with these claims.

METHOD

We reviewed the literature to examine the extent to which this theoretical model is supported by the evidence.

RESULTS

We show that evidence derived from fundamental research in human cognition and studies in clinical medicine challenges the basic assumptions of this theory-that errors arise in System 1 processing as a consequence of cognitive biases, and are corrected by slow, deliberative analytical processing. We claim that, to the contrary, errors derive from both System 1 and System 2 reasoning, that they arise from lack of access to the appropriate knowledge, not from errors of processing, and that the two processes are not essential to the process of diagnostic reasoning.

CONCLUSIONS

The two processing modes are better understood as a consequence of the nature of the knowledge retrieved, not as independent processes.

The inseparability of context and clinical reasoning

Early descriptions of clinical reasoning have described a dual process model that relies on analytical or nonanalytical approaches to develop a working diagnosis. In this classic research, clinical reasoning is portrayed as an individual-driven cognitive process based on gathering information from the patient encounter, forming mental representations that rely on previous experience and engaging developed patterns to drive working diagnoses and management plans. Indeed, approaches to patient safety, as well as teaching and assessing clinical reasoning focus on the individual clinician, often ignoring the complexity of the system surrounding the diagnostic process. More recent theories and evidence portray clinical reasoning as a dynamic collection of processes that takes place among and between persons across clinical settings. Yet, clinical reasoning, taken as both an individual and a system process, is insufficiently supported by theories of cognition based on individual clinicals and lacks the specificity needed to describe the phenomenology of clinical reasoning. In this review, we reinforce that the modern healthcare ecosystem - with its people, processes and technology - is the context in which health care encounters and clinical reasoning take place.

The influence of context on diagnostic reasoning: A narrative synthesis of experimental findings

AIMS AND OBJECTIVES

Contextual information which is implicitly available to physicians during clinical encounters has been shown to influence diagnostic reasoning. To better understand the psychological mechanisms underlying the influence of context on diagnostic accuracy, we conducted a review of experimental research on this topic.

METHOD

We searched Web of Science, PubMed, and Scopus for relevant articles and looked for additional records by reading the references and approaching experts. We limited the review to true experiments involving physicians in which the outcome variable was the accuracy of the diagnosis.

RESULTS

The 43 studies reviewed examined two categories of contextual variables: (a) case-intrinsic contextual information and (b) case-extrinsic contextual information. Case-intrinsic information includes implicit misleading diagnostic suggestions in the disease history of the patient, or emotional volatility of the patient. Case-extrinsic or situational information includes a similar (but different) case seen previously, perceived case difficulty, or external digital diagnostic support. Time pressure and interruptions are other extrinsic influences that may affect the accuracy of a diagnosis but have produced conflicting findings.

CONCLUSION

We propose two tentative hypotheses explaining the role of context in diagnostic accuracy. According to the negative-affect hypothesis, diagnostic errors emerge when the physician's attention shifts from the relevant clinical findings to the (irrelevant) source of negative affect (for instance patient aggression) raised in a clinical encounter. The early-diagnosis-primacy hypothesis attributes errors to the extraordinary influence of the initial hypothesis that comes to the physician's mind on the subsequent collecting and interpretation of case information. Future research should test these mechanisms explicitly. Possible alternative mechanisms such as premature closure or increased production of (irrelevant) rival diagnoses in response to context deserve further scrutiny. Implications for medical education and practice are discussed.

Role of knowledge and reasoning processes as predictors of resident physicians' susceptibility to anchoring bias in diagnostic reasoning: a randomised controlled experiment

BACKGROUND

Diagnostic errors have been attributed to reasoning flaws caused by cognitive biases. While experiments have shown bias to cause errors, physicians of similar expertise differed in susceptibility to bias. Resisting bias is often said to depend on engaging analytical reasoning, disregarding the influence of knowledge. We examined the role of knowledge and reasoning mode, indicated by diagnosis time and confidence, as predictors of susceptibility to anchoring bias. Anchoring bias occurs when physicians stick to an incorrect diagnosis triggered by early salient distracting features (SDF) despite subsequent conflicting information.

METHODS

Sixty-eight internal medicine residents from two Dutch university hospitals participated in a two-phase experiment. Phase 1: assessment of knowledge of discriminating features (ie, clinical findings that discriminate between lookalike diseases) for six diseases. Phase 2 (1 week later): diagnosis of six cases of these diseases. Each case had two versions differing exclusively in the presence/absence of SDF. Each participant diagnosed three cases with SDF (SDF+) and three without (SDF-). Participants were randomly allocated to case versions. Based on phase 1 assessment, participants were split into higher knowledge or lower knowledge groups.

MAIN OUTCOME MEASUREMENTS

frequency of diagnoses associated with SDF; time to diagnose; and confidence in diagnosis.

RESULTS

While both knowledge groups performed similarly on SDF- cases, higher knowledge physicians succumbed to anchoring bias less frequently than their lower knowledge counterparts on SDF+ cases (p=0.02). Overall, physicians spent more time (p<0.001) and had lower confidence (p=0.02) on SDF+ than SDF- cases (p<0.001). However, when diagnosing SDF+ cases, the groups did not differ in time (p=0.88) nor in confidence (p=0.96).

CONCLUSIONS

Physicians apparently adopted a more analytical reasoning approach when presented with distracting features, indicated by increased time and lower confidence, trying to combat bias. Yet, extended deliberation alone did not explain the observed performance differences between knowledge groups. Success in mitigating anchoring bias was primarily predicted by knowledge of discriminating features of diagnoses.

Insights into diagnostic errors in endocrinology: a prospective, case-based, international study

BACKGROUND

Diagnostic errors in internal medicine are common. While cognitive errors have previously been identified to be the most common contributor to errors, very little is known about errors in specific fields of internal medicine such as endocrinology. This prospective, multicenter study focused on better understanding the causes of diagnostic errors made by general practitioners and internal specialists in the area of endocrinology.

METHODS

From August 2019 until January 2020, 24 physicians completed five endocrine cases on an online platform that simulated the diagnostic process. After each case, the participants had to state and explain why they chose their assumed diagnosis. The data gathering process as well as the participants' explanations were quantitatively and qualitatively analyzed to determine the causes of the errors. The diagnostic processes in correctly and incorrectly solved cases were compared.

RESULTS

Seven different causes of diagnostic error were identified, the most frequent being misidentification (mistaking one diagnosis with a related one or with more frequent and similar diseases) in 23% of the cases. Other causes were faulty context generation (21%) and premature closure (17%). The diagnostic confidence did not differ between correctly and incorrectly solved cases (median 8 out of 10, p = 0.24). However, in incorrectly solved cases, physicians spent less time on the technical findings (such as lab results, imaging) (median 250 s versus 199 s, p < 0.049).

CONCLUSIONS

The causes for errors in endocrine case scenarios are similar to the causes in other fields of internal medicine. Spending more time on technical findings might prevent misdiagnoses in everyday clinical practice.

Deliberate reflection and clinical reasoning: Founding ideas and empirical findings

CONTEXT

The idea that reflection improves reasoning and learning, since long present in other fields, emerged in the 90s in the medical education literature. Since then, the number of publications on reflection as a means to improve diagnostic learning and clinical problem-solving has increased steeply. Recently, concerns with diagnostic errors have raised further interest in reflection. Several approaches based on reflection have been proposed to reduce clinicians' errors during diagnostic reasoning. What reflection entails varies substantially, and most approaches still require empirical examination.

PURPOSE

The present essay aims to help clarify the role of deliberate reflection in diagnostic reasoning. Deliberate reflection is an approach whose effects on diagnostic reasoning and learning have been empirically studied over the past 15 years. The philosophical roots of the approach will be briefly examined, and the theory and practice of deliberate reflection, particularly its effectiveness, will be reviewed. Lessons learned and unresolved issues will be discussed.

DISCUSSION

The deliberate reflection approach originated from a conceptualization of the nature of reflection practice in medicine informed by Dewey's and Schön's work. The approach guides physicians through systematically reviewing the grounds of their initial diagnosis and considering alternatives. Experimental evidence has supported the effectiveness of deliberate reflection in increasing physicians' diagnostic performance, particularly in nonstraightforward diagnostic tasks. Deliberate reflection has also proved helpful to improve students' diagnostic learning and to facilitate learning of new information. The mechanisms behind the effects of deliberate reflection remain unclear. Tentative explanations focus on the activation/reorganisation of prior knowledge induced by deliberate reflection. Its usefulness depends therefore on the difficulty of the problem relative to the clinician's knowledge. Further research should examine variations in instructions on how to reflect upon a case, the value of further guidance while learning from deliberate reflection, and its benefits in real practice.

Does a suggested diagnosis in a general practitioners' referral question impact diagnostic reasoning: an experimental study

BACKGROUND

Diagnostic errors are a major cause of preventable patient harm. Studies suggest that presenting inaccurate diagnostic suggestions can cause errors in physicians' diagnostic reasoning processes. It is common practice for general practitioners (GPs) to suggest a diagnosis when referring a patient to secondary care. However, it remains unclear via which underlying processes this practice can impact diagnostic performance. This study therefore examined the effect of a diagnostic suggestion in a GP's referral letter to the emergency department on the diagnostic performance of medical interns.

METHODS

Medical interns diagnosed six clinical cases formatted as GP referral letters in a randomized within-subjects experiment. They diagnosed two referral letters stating a main complaint without a diagnostic suggestion (control), two stating a correct suggestion, and two stating an incorrect suggestion. The referral question and case order were randomized. We analysed the effect of the referral question on interns' diagnostic accuracy, number of differential diagnoses, confidence, and time taken to diagnose.

RESULTS

Forty-four medical interns participated. Interns considered more diagnoses in their differential without a suggested diagnosis (M = 1.85, SD = 1.09) than with a suggested diagnosis, independent of whether this suggestion was correct (M = 1.52, SD = 0.96, d = 0.32) or incorrect ((M = 1.42, SD = 0.97, d = 0.41), χ2(2) =7.6, p = 0.022). The diagnostic suggestion did not influence diagnostic accuracy (χ2(2) = 1.446, p = 0.486), confidence, (χ2(2) = 0.058, p = 0.971) or time to diagnose (χ2(2) = 3.128, p = 0.209).

CONCLUSIONS

A diagnostic suggestion in a GPs referral letter did not influence subsequent diagnostic accuracy, confidence, or time to diagnose for medical interns. However, a correct or incorrect suggestion reduced the number of diagnoses considered. It is important for healthcare providers and teachers to be aware of this phenomenon, as fostering a broad differential could support learning. Future research is necessary to examine whether these findings generalize to other healthcare workers, such as more experienced specialists or triage nurses, whose decisions might affect the diagnostic process later on.

TRIAL REGISTRATION

The study protocol was preregistered and is available online at Open Science Framework ( https://osf.io/7de5g ).

Learning from Missed Opportunities Through Reflective Practice

Identification of diagnostic errors is difficult but is not alone sufficient for performance improvement. Instead, cases must be reflected on to identify ways to improve decision-making in the future. There are many tools and modalities to retrospectively reflect on action to study medical decisions and outcomes and improve future performance. Reflection in action-in which diagnostic decisions are considered in real-time-may also improve medical decision-making especially through strategies such as structured reflection. Ongoing regular feedback can normalize the discussion about improving decision-making, enable reflective practice, and improve decision making.