Measuring sociocultural engagement of health professions education students: a psychometric study.

BACKGROUND: Sociocultural engagement of students refers to broadening viewpoints and providing awareness of, and respect for, diverse backgrounds and perspectives. However, there are no existing validated instruments in the literature for measuring sociocultural engagement of health professions education (HPE) students. Therefore, the aim of this study is to develop and validate a questionnaire designed to assess sociocultural engagement among HPE students. METHODS: The study included undergraduate HPE students (n = 683) at Gulf Medical University. The initial version of the sociocultural engagement of students' questionnaire (SESQ) was developed after extensive literature review and guided by the Global Learning Qualifications Framework. We then tested the content validity of the questionnaire by using focus group discussion with subject experts (n = 16) and pilot testing with students (n = 20). We distributed the content-validated version of the SESQ (16 items) to undergraduate students in six HPE colleges. To examine the construct validity and construct reliability of the questionnaire, we conducted exploratory factor analysis, followed by confirmatory factor analysis. RESULTS: Confirmatory factor analysis supported the two-factor structure which consists of 13 items with good fitness indices (χ2 = 214.35, df = 61, χ 2/df = 3.51, CFI = 0.98, RMSEA = 0.06, SRMR = 0.025, and AIC = 208.00). The two factors were sociocultural interactions (8 items) and sociocultural adaptation (5 items). The construct reliability of the total questionnaire is 0.97 and the two factors were 0.93 and 0.92 for sociocultural interactions and sociocultural adaptation, respectively. In addition, there were significant weak correlations between both factors of sociocultural engagement scores and student satisfaction with the university experience (r = .19 for each, P = .01). CONCLUSIONS: The sociocultural engagement of students' questionnaire exhibits good evidence of construct validity and reliability. Further studies will be required to test the validity of this questionnaire in other contexts.

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.

Influence of tutor interventions and group process on medical students' engagement in problem-based learning.

INTRODUCTION: Student engagement is influenced by several variables, among which are the teaching styles employed by faculty. In problem-based learning (PBL), the role of faculty is to facilitate the learning of the tutorial group as they work through clinical problems. However, the influence of tutor intervention styles and group process on engagement of students in PBL tutorials is unclear. METHODS: The study was conducted with year 2 and 3 medical students (n = 176) in PBL tutorial groups at the end of an integrated PBL course. Students evaluated their behavioural, cognitive and emotional engagement in PBL tutorials using a pre-validated 11-item questionnaire. Students also filled in a modified version of a previously published tutor intervention profile (TIP) questionnaire. The modified TIP questionnaire represents three constructs (1) steering the learning process (6 items), (2) stimulating student autonomy (4 items) and (3) establishing relatedness with students (3 items). In addition, PBL group process was evaluated using a 5-item nominal scale: (1) tutorial atmosphere, (2) listening and information sharing, (3) group performance, (4) decision making and (5) reaction to leadership. RESULTS: Establishing sense of relatedness in the group by PBL tutors was the most important predictor of emotional engagement (F = 41.213, ΔR2 = 0.191, ß = 0.438, P = 0.000). On the other hand, steering the learning process was a significant predictor of behavioural engagement (F = 19.0, ΔR2=0.098, ß = 0.314, P = 0.000). However, stimulating student autonomy was not a significant predictor of student engagement in PBL tutorials. On the other hand, enhancing the group process in PBL tutorials significantly predicts student engagement with strong impact on emotional and cognitive engagement of students. CONCLUSIONS: Establishing the sense of relatedness in the group and steering the learning process by PBL tutors as well as improving PBL group process are significant predictors of student engagement in PBL tutorials with emotional and cognitive engagement being the most sensitive variables affected.

Serendipity in oto-rhino-laryngology.

INTRODUCTION: Serendipitous findings are findings that were initially unsought but nevertheless contribute to the development of the discipline. This article reviews eight serendipitous findings in oto-rhino-laryngology important to its advancement. METHOD: The following serendipitous findings are discussed: the accidental discovery of the laryngeal mirror and indirect laryngoscopy by Garcia (1854), the invention of direct oesophagoscopy by Kußmaul (circa 1868), Czermák's (1863) development of diaphanoscopy, the unintentional emergence of bronchography from a clinical error made by Weingartner (1914), adenotomy by Meyer (1869), the discovery of the causes of unbalance related to the vestibular nerve by Flourens (1830), Bárány's (1914) finding that the semi-circular canal reflex is involved in equilibrium, and the relationship between gastroesophageal reflux and middle-ear infections by Poelmans and Feenstra (2002). DISCUSSION: Based on these case studies we conclude that serendipity, defined as the art of making an initially unsought find, does not always appear out of nowhere. Often the researcher is already wrestling with a problem for which the serendipitous finding provides a solution. Sometimes the serendipitous finding enables the application of a known solution to a new problem. And sometimes a serendipitous finding is not recognized as such or considered unimportant. Since observations tend to be theory-loaded, having appropriate background knowledge is a conditio sine qua non to elaborate an unanticipated observation.

Overconfidence, Time-on-Task, and Medical Errors: Is There a Relationship?

Background: Literature suggest that physicians' high level of confidence has a negative impact on medical decisions, and this may lead to medical errors. Experimental research is lacking; however, this study investigated the effects of high confidence on diagnostic accuracy. Methods: Forty internal medicine residents from different hospitals in Saudi Arabia were divided randomly into two groups: A high-confidence group as an experimental and a low-confidence group acting as a control. Both groups solved each of eight written complex clinical vignettes. Before diagnosing these cases, the high-confidence group was led to believe that the task was easy, while the low-confidence group was presented with information from which it could deduce that the diagnostic task was difficult. Level of confidence, response time, and diagnostic accuracy were recorded. Results: The participants in the high-confidence group had a significantly higher confidence level than those in the control group: 0.75 compared to 0.61 (maximum 1.00). However, neither time on task nor diagnostic accuracy significantly differed between the two groups. Conclusion: In the literature, high confidence as one of common cognitive biases has a strong association with medical error. Even though the high-confidence group spent somewhat less time on the cases, suggesting potential premature decision-making, we failed to find differences in diagnostic accuracy. It is suggested that overconfidence should be studied as a personality trait rather than as a malleable characteristic.

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.

Construct validity of a questionnaire for measuring student engagement in problem-based learning tutorials.

BACKGROUND: Student engagement is student investment of time and energy in academic and non-academic experiences that include learning, teaching, research, governance, and community activities. Although previous studies provided some evidence of measuring student engagement in PBL tutorials, there are no existing quantitative studies in which cognitive, behavioral, and emotional engagement of students in PBL tutorials is measured. Therefore, this study aims to develop and examine the construct validity of a questionnaire for measuring cognitive, behavioral, and emotional engagement of students in PBL tutorials. METHODS: A 15-item questionnaire was developed guided by a previously published conceptual framework of student engagement. Focus group discussion (n = 12) with medical education experts was then conducted and the questionnaire was piloted with medical students. The questionnaire was then distributed to year 2 and 3 medical students (n = 176) in problem-based tutorial groups at the end of an integrated course, where PBL is the main strategy of learning. The validity of the internal structure of the questionnaire was tested by confirmatory factor analysis using structural equation modeling assuming five different models. Predictive validity evidence of the questionnaire was studied by examining the correlations between students' engagement and academic achievement. RESULTS: Confirmatory factor analysis indicates a good fit between the measurement and structural model of an 11-item questionnaire composed of a three-factor structure: behavioral engagement (3 items), emotional engagement (4 items), and cognitive engagement (4 items). Models in which the three latent factors were considered semi-independent provided the best fit. The construct reliabilities of behavioral, cognitive, and emotional factors were 0.82, 0.82, and 0.76, respectively. We failed however to find significant relationships between academic achievement and engagement. CONCLUSIONS: We found a strong evidence to support the construct validity of a three-factor structure of student engagement in PBL tutorial questionnaire. Further studies are required to test the validity of this instrument in other educational settings. The predictive validity is another area needing further scrutiny.

Physicians' duty to climate protection as an expression of their professional identity: a defence from Korsgaard's neo-Kantian moral framework.

The medical profession is observing a rising number of calls to action considering the threat that climate change poses to global human health. Theory-led bioethical analyses of the scope and weight of physicians' normative duty towards climate protection and its conflict with individual patient care are currently scarce. This article offers an analysis of the normative issues at stake by using Korsgaard's neo-Kantian moral account of practical identities. We begin by showing the case of physicians' duty to climate protection, before we succinctly introduce Korsgaard's account. We subsequently show how the duty to climate protection can follow from physicians' identity of being a healthcare professional. We structure conflicts between individual patient care and climate protection, and show how a transformation in physicians' professional ethos is possible and what mechanisms could be used for doing so. An important limit of our analysis is that we mainly address the level of individual physicians and their practical identities, leaving out important measures to respond to climate change at the mesolevels and macrolevels of healthcare institutions and systems, respectively.

Measurement of student engagement in health professions education: a review of literature.

Student engagement is a complex multidimensional construct that has attained great interest in health professions education (HPE). Definition and conceptualization of student engagement is an important step that should drive the development of the instruments for its measurement. We have recently proposed a comprehensive framework for student engagement in HPE with a definition of engagement as student investment of time and energy in academic and non-academic experiences that include learning, teaching, research, governance, and community activities. The dimensions of student engagement in this framework included the cognitive, affective, behavioral, agentic, and socio-cultural. Guided by the student engagement framework, this non-systematic review aims to identify, critically appraise, and summarize the existing methods for measuring student engagement in HPE. Extrapolating from higher education literature, we attempted to link the theoretical perspectives of student engagement with the published methods of its measurement in HPE context. In addition, we have described the different methods of measuring student engagement including self-report surveys, real time measures, direct observation, interviews/focus groups, and the use of multiple instruments. The span of engagement dimensions measured by self-report surveys ranges from one to five dimensions. However, measurement of agentic and sociocultural dimensions of engagement in HPE is still limited and further research is required. We have also reflected on the existing methods of measuring engagement of students as active partners in HPE. The review also describes the advantages, limitations, and psychometric properties of each method for measuring student engagement. We ended the review with a guiding conclusion on how to develop and select an instrument for measuring student engagement in HPE. Finally, we addressed the gaps in the literature about measuring engagement of HPE students and future research plans.

"Studying cognitive reappraisal as an antidote to the effect of negative emotions on medical residents' learning: a randomized experiment".

BACKGROUND: Medical trainees often encounter situations that trigger emotional reactions which may hinder learning. Evidence of this effect on medical trainees is scarce and whether it could be counteracted is unclear. This study investigated the effect of negative emotions on medical residents' learning and whether cognitive reappraisal counteracts it. METHODS: Ninety-nine medical residents participated in a three-phase experiment consisting of: (1) watching a video, either a neutral or an emotion-induction version, the latter either followed by cognitive reappraisal or not (2) learning: all participants studied the same medical text; study-time and cognitive engagement were measured; (3) test: a recall-test measured learning. Data was analysed using Chi-square test and one-way ANOVA. RESULTS: Study time significantly varied between conditions (p = 0.002). The two emotional conditions spent similar time, both significantly less than the neutral condition. The difference in test scores failed to reach significance level (p = 0.053). While the emotional conditions performed similarly, their scores tended to be lower than those of the neutral condition. CONCLUSION: Negative emotions can adversely affect medical residents' learning. The effect of emotions was not counteracted by cognitive reappraisal, which has been successfully employed to regulate emotions in other domains. Further research to examine emotion regulation strategies appropriate for medical education is much needed.

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.

Improving diagnostic decision support through deliberate reflection: a proposal.

Digital decision support (DDS) is expected to play an important role in improving a physician's diagnostic performance and reducing the burden of diagnostic error. Studies with currently available DDS systems indicate that they lead to modest gains in diagnostic accuracy, and these systems are expected to evolve to become more effective and user-friendly in the future. In this position paper, we propose that a way towards this future is to rethink DDS systems based on deliberate reflection, a strategy by which physicians systematically review the clinical findings observed in a patient in the light of an initial diagnosis. Deliberate reflection has been demonstrated to improve diagnostic accuracy in several contexts. In this paper, we first describe the deliberate reflection strategy, including the crucial element that would make it useful in the interaction with a DDS system. We examine the nature of conventional DDS systems and their shortcomings. Finally, we propose what DDS based on deliberate reflection might look like, and consider why it would overcome downsides of conventional DDS.

Taking a moral holiday? Physicians' practical identities at the margins of professional ethics.

Physicians frequently encounter situations in which their professional practice is intermingled with moral affordances stemming from other domains of the physician's lifeworld, such as family and friends, or from general morality pertaining to all humans. This article offers a typology of moral conflicts 'at the margins of professionalism' as well as a new theoretical framework for dealing with them. We start out by arguing that established theories of professional ethics do not offer sufficient guidance in situations where professional ethics overlaps with moral duties of other origins. Therefore, we introduce the moral theory developed by Christine M. Korsgaard, that centres around the concept of practical identity. We show how Korsgaard's account offers a framework for interpreting different types of moral conflicts 'at the margins of professionalism' to provide either orientation for solving the conflict or an explanation for the emotional and moral burden involved in moral dilemmas.

Failure to demonstrate effects of interruptions on diagnostic reasoning: three experiments.

BACKGROUND: Diagnostic error is a major source of patient suffering. Researchshows that physicians experience frequent interruptions while being engaged with patients and indicate that diagnostic accuracy may be impaired as a result. Since most studies in the field are observational, there is as yet no evidence suggesting a direct causal link between being interrupted and diagnostic error. Theexperiments reported in this article were intended to assess this hypothesis. METHODS: Three experiments were conducted to test the hypothesis that interruptions hurt diagnostic reasoning and increase time on task. In the first experiment (N = 42), internal medicine residents, while diagnosing vignettes of actual clinical cases were interrupted halfway with a task unrelated to medicine, solving word-spotting puzzles and anagrams. In the second experiment (N = 78), the interruptions were medically relevant ones. In the third experiment (N = 30), we put additional time pressure on the participants. In all these experiments, a control group diagnosed the cases without interruption. Dependent variables were diagnostic accuracy and amount of time spent on the vignettes. RESULTS: In none of the experiments interruptions were demonstrated to influence diagnostic accuracy. In Experiment 1: Mean of interrupted group was 0.88 (SD = 0.37) versus non- interrupted group 0.91 (SD = 0.32). In Experiment 2: Mean of interrupted group was 0.95 (SD = 0.32) versus non-interrupted group 0.94 (SD = 0.38). In Experiment 3: Mean of interrupted group was 0.42 (SD = 0.12) versus non-interrupted group 0.37 (SD = 0.08). Although interrupted residents in all experiments needed more time to complete the diagnostic task, only in Experiment 2, this effect was statistically significant. CONCLUSIONS: These three experiments, taken together, failed to demonstrate negative effects of interruptions on diagnostic reasoning. Perhaps physicians who are interrupted may still have sufficient cognitive resources available to recover from it most of the time.

What happens to misunderstandings of biomedical concepts across a medical curriculum?

Research on the extent and nature of commonly misunderstood fundamental biomedical concepts across a medical curriculum is scarce. These misunderstandings could point toward robust misconceptions. We examined first whether common misunderstandings persist throughout a medical curriculum, followed by a fine-grained analysis to identify their nature. We designed and administered a 2-tier test to 987 medical students across our curriculum, with 8 questions covering the respiratory and cardiovascular systems, cell division, and homeostatic processes. Proportions of incorrect responses were computed. Four questions where misunderstandings persisted were further qualitatively analyzed. A one-way ANOVA showed the proportion of incorrect responses decreased significantly by students' academic year [F(6, 986) = 96.05, P < 0.001]. While novices and end-of -first-year students showed similar proportion of incorrect responses (P > 0.05), incorrect responses decreased significantly between first years and second years (P < 0.001). Thereafter, the proportion of incorrect responses remained stable from second to final year (P > 0.05), with ∼35% of incorrect responses. Five questions showed no decrease of incorrect responses between second and final years, with two questions where final year students performed marginally better than novices. A Chi-square analysis, with Bonferroni post hoc test, showed certain misunderstandings appeared frequently across the curriculum. The qualitative analysis of the open-ended questions yielded 15 categories of common misunderstandings of fundamental biomedical concepts in all years of training. If educators become aware of commonly misunderstood biomedical concepts, preventative measures could be taken to prevent robust misconceptions.

Promotion of knowledge transfer and retention in year 2 medical students using an online training exercise.

It was recently shown that novice medical students could be trained to demonstrate the speed-to-diagnosis and diagnostic accuracy typical of System-1-type reasoning. However, the effectiveness of this training can only be fully evaluated when considering the extent to which knowledge transfer and long-term retention occur as a result, the former of which is known to be notoriously difficult to achieve. This study aimed to investigate whether knowledge learned during an online training exercise for chest X-ray diagnosis promoted either knowledge transfer or retention, or both. Second year medical students were presented with, and trained to recognise the features of four chest X-ray conditions. Subsequently, they were shown the four trained-for cases again as well as different representations of the same conditions varying in the number of common elements and asked to provide a diagnosis, to test for near-transfer (four cases) and far-transfer (four cases) of knowledge. They were also shown four completely new conditions to diagnose. Two weeks later they were asked to diagnose the 16 aforementioned cases again to assess for knowledge retention. Dependent variables were diagnostic accuracy and time-to-diagnosis. Thirty-six students volunteered. Trained-for cases were diagnosed most accurately and with most speed (mean score = 3.75/4, mean time = 4.95 s). When assessing knowledge transfer, participants were able to diagnose near-transfer cases more accurately (mean score = 2.08/4, mean time = 15.77 s) than far-transfer cases (mean score = 1.31/4, mean time = 18.80 s), which showed similar results to those conditions previously unseen (mean score = 0.72/4, mean time = 19.46 s). Retention tests showed a similar pattern but accuracy scores were lower overall. This study demonstrates that it is possible to successfully promote knowledge transfer and retention in Year 2 medical students, using an online training exercise involving diagnosis of chest X-rays, and is one of the few studies to provide evidence of actual knowledge transfer.

Improving Handoff by Deliberate Cognitive Processing: Results from a Randomized Controlled Experimental Study.

BACKGROUND: Although a number of successful handoff interventions have been reported, the handoff process remains vulnerable because it relies on memory. The aim of this study was to investigate the effect of deliberate cognitive processing (i.e., analytical, conscious, and effortful thinking) on recall of information from a simulated handoff. METHODS: This two-phased experiment was executed in the Netherlands in 2015. A total of 78 pediatric residents were randomly divided into an intervention group (n = 37) and a control group (n = 41). In phase 1, participants received written handoffs from 8 patients. The intervention group was asked to develop a contingency plan for each patient, deliberately processing the information. The control group received no specific instructions. In phase 2, all participants were asked to write down as much as they recalled from the handoffs. The outcome was the amount and accuracy of recalled information, calculated by scoring for idea units (single information elements) and inferences (conclusions computed by participants based on two or more idea units). RESULTS: Participants in the intervention group recalled significantly more inferences (7.24 vs. 3.22) but fewer correct idea units (21.1% vs. 25.3%) than those in the control group. There was no difference with regard to incorrectly recalled information. CONCLUSION: Our study revealed that deliberate cognitive processing leads to creation of more correct inferences, but fewer idea units. This suggests that deliberate cognitive processing results in interpretation of the information into higher level concepts, rather than remembering specific pieces of information separately. This implies better understanding of patients' problems.

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

BACKGROUND: Bias in reasoning rather than knowledge gaps has been identified as the origin of most diagnostic errors. However, the role of knowledge in counteracting bias is unclear. OBJECTIVE: To examine whether knowledge of discriminating features (findings that discriminate between look-alike diseases) predicts susceptibility to bias. DESIGN: Three-phase randomized experiment. Phase 1 (bias-inducing): Participants were exposed to a set of clinical cases (either hepatitis-IBD or AMI-encephalopathy). Phase 2 (diagnosis): All participants diagnosed the same cases; 4 resembled hepatitis-IBD, 4 AMI-encephalopathy (but all with different diagnoses). Availability bias was expected in the 4 cases similar to those encountered in phase 1. Phase 3 (knowledge evaluation): For each disease, participants decided (max. 2 s) which of 24 findings was associated with the disease. Accuracy of decisions on discriminating features, taken as a measure of knowledge, was expected to predict susceptibility to bias. PARTICIPANTS: Internal medicine residents at Erasmus MC, Netherlands. MAIN MEASURES: The frequency with which higher-knowledge and lower-knowledge physicians gave biased diagnoses based on phase 1 exposure (range 0-4). Time to diagnose was also measured. KEY RESULTS: Sixty-two physicians participated. Higher-knowledge physicians yielded to availability bias less often than lower-knowledge physicians (0.35 vs 0.97; p = 0.001; difference, 0.62 [95% CI, 0.28-0.95]). Whereas lower-knowledge physicians tended to make more of these errors on subjected-to-bias than on not-subjected-to-bias cases (p = 0.06; difference, 0.35 [CI, - 0.02-0.73]), higher-knowledge physicians resisted the bias (p = 0.28). Both groups spent more time to diagnose subjected-to-bias than not-subjected-to-bias cases (p = 0.04), without differences between groups. CONCLUSIONS: Knowledge of features that discriminate between look-alike diseases reduced susceptibility to bias in a simulated setting. Reflecting further may be required to overcome bias, but succeeding depends on having the appropriate knowledge. Future research should examine whether the findings apply to real practice and to more experienced physicians.