What does research on clinical reasoning have to say to clinical teachers ?

Recebido em: 13 mar. 2020. Aprovado em: 05 abr. 2020. Publicado em: 19 jun. 2020. Abstract: Clinical reasoning is a crucial determinant of physicians’ performance. It is key to arrive at a correct diagnosis, which substantially increases the chance of appropriate therapeutic decisions. Clinical teachers face the daily challenge of helping their students to develop clinical reasoning. To select appropriate teaching strategies, it may be useful to become acquainted with the results of the research on clinical reasoning that has been conducted over the last decades. This article synthesizes the findings of this research that help in particular to understand the cognitive processes involved in clinical reasoning, the trajectory that leads the student from novice to expert, and instructional approaches that have been shown to be useful to facilitating this trajectory. The focus of the article is the diagnostic process, because it is about it that most research has been conducted. This research indicates that there is not a particular reasoning strategy that is specific to expert physicians and could be taught to students. It is the availability of a large knowledge base organized in memory in illness scripts of different formats that explains the expert’s better performance. The more, the richer, and the more well-structured are the illness scripts a physician has stored in memory, the more he/she would be able to make accurate diagnoses. These scripts are formed gradually over the years of education. To help develop them, students should be exposed to a wide variety of clinical problems, with which they must interact actively. Instructional approaches that require students to systematically reflect on problems, analyzing differences and similarities between them, explaining underlying mechanisms, comparing and contrasting alternative diagnoses, have proved useful to help refine disease scripts. These approaches are valuable tools for teachers concerned with the development of their students clinical reasoning.


What does research on clinical reasoning have to say to clinical teachers?
O que a pesquisa sobre raciocínio clínico tem a dizer a preceptores e professores de áreas clínicas?

Introduction
The physician in an emergency department sees a 27-year-old patient with non-productive cough and pain in the right hemithorax that started 24

How clinical reasoning leads the doctor to the diagnosis
The first research programs on clinical reasoning, in the 1970s, aimed to understand the reasoning process that an experienced doctor uses to solve problems, which could then be taught to the student [1]. From these programs emerged the idea that the 'hypothetical-deductive reasoning model' would characterize an expert doctor. At the beginning of the clinical encounter, the physician would generate diagnostic hypotheses and then obtain more information to confirm or refute these hypotheses [2]. However, difficulties emerged soon, when several studies showed that, in fact, from beginners to experienced doctors, everyone used more or less the same hypotheticaldeductive reasoning process [2,3]. The difference between experts and novices was simply that the experts generated better hypotheses. Rather than any peculiarity of the reasoning process, the accuracy of the initial hypothesis predicted the accuracy of the diagnosis [4]. Moreover, an expert's performance on one problem did not predict performance on another problem, even within the same specialty, a phenomenon that became known as 'content specificity' [2,5,6].
These findings brought substantial evidence against the idea that experts used a particular type of reasoning process and that a general reasoning skill existed that would explain their best performance and could be taught to students. Research then turned to the content, that is, expert knowledge, moving to examine types of knowledge, how 3/8 knowledge was organized in memory, activated and used in diagnostic reasoning [1].
Several theories exist about the cognitive structures that organize expert knowledgesemantic networks, examples, prototypes, scripts -and indeed different forms of organization probably coexist in memory and are used depending on the circumstances [7]. The basic idea is that a mental representation of a disease knowledge associates that disease with a set of 'findings' ('findings' in a comprehensive sense).
Briefly, what happens in the diagnostic process is that some findings of the problem activate in the physician's memory the knowledge of the disease to which they are associated, and a hypothesis is generated. This triggers a search, guided by the mental representation of the disease, for additional information to check if other findings associated with that disease are also present. When the search reveals findings that contradict the initial hypothesis, another hypothesis is generated, restarting the process.
In recent years, this basic model of clinical reasoning has gained support from research in psychology. This research has generated substantial empirical evidence for the existence of two different forms of reasoning, one that is based on pattern recognition, fast, automatic and largely intuitive, and another that depends on the application of rules, is slow, demands effort and is subject to conscious control [8][9][10]. The literature usually refers two these to reasoning modes as Type 1 (or System 1) and Type 2 (or System 2). They apparently apply well to the diagnostic process, with Type 1 involved in hypothesis generation and Type 2 in its verification. While some authors associate cognitive biases (and consequent diagnostic errors) with failures of Type 1 mode [11,12], others argue that such errors do not derive from a particular reasoning process but from specific gaps in knowledge about the disease at hand [13]. This debate is beyond the scope of this article, but recent reviews are available for those interested on it [14,15].
Note that the idea from the beginning of research on clinical reasoning of a hypothetical-deductive diagnostic reasoning process remains. However, it is now recognized that this is not a reasoning process independent of content, but rather a strategy to access and use knowledge organized in representations of diseases stored in memory [1,16].  [17,18]. In the initial years, the student quickly forms causal networks in memory, linking clinical findings to the pathophysiological processes that produced them. At this stage, students still do not yet recognize patterns of findings that usually come together and, when solving clinical cases, explain isolated findings based on pathophysiological processes [19].
As this knowledge is used to understand clinical problems, it is gradually 'encapsulated' in more generic explanatory models that group together different concepts and their relationships [17,20]. Practice with patients induces a second change in the way knowledge is organized, with the development of 'illness scripts' [17,21,22].
Scripts are cognitive structures that 'represent' a patient with that disease, containing knowledge of the conditions that make the disease more or less likely, the clinical manifestations of the disease, and its pathophysiological processes, the latter more succinct because of encapsulation.
There are scripts of different levels of specificity, representing disease prototypes, diagnostic categories, or even traces in the memory of real patients previously seen [17,23].
Illness scripts play a crucial role in the diagnostic process. In the first moments of a clinical encounter, patient characteristics activate an illness script in the doctor's memory, and a diagnostic hypothesis is generated. The script then guides the search for more information, with the doctor basically checking whether the patient's findings match the elements of the script [17,21].
As experience with patients with a certain disease grows, the physician tends to incorporate into his/her script not only the findings of the typical presentation of the disease, but also the atypical formats, which makes him/her able to recognize the disease even when it does not present as it appears in the textbooks. The more illness scripts the doctor has stored in memory and the richer and better structured the scripts are, the more well prepared he/she would be for the diagnostic process. Fostering the development of a large base of illness scripts is therefore crucial to help students develop clinical reasoning [16][17][18].

The teaching of clinical reasoning
From all these years of research on clinical reasoning, one conclusion seems clear. Because there is neither a generic reasoning skill that is carried from one problem to another nor an expert's specific reasoning mode, it makes no sense to intend to teach the student 'how to reason' [16,24]. Since it is an extensive knowledge base that determines diagnostic performance, the primary task is to help students develop such base.
Although this conclusion is widely supported by empirical evidence, it is not always reflected in the literature on the teaching of clinical reasoning.
A recent review has shown that descriptions of curricula/courses that are intended to teach decision-making theory and/or a specific reasoning strategy are still common [24]. The literature on diagnostic error also often presents proposals for interventions that aim to reduce susceptibility to cognitive biases by teaching reasoning strategies to counteract them. The few studies that have evaluated the effects of such educational interventions on actual diagnostic performance indicate minimal impact or none [25,26]. In contrast, strategies aimed at increasing specific knowledge, for example of critical findings that help distinguish between similar-looking diseases, seem promising to 'immunize' against bias in reasoning [27].
Knowing that there seems to be no way to teach 'how to reason' may look disappointing to teachers. First, providing students with appropriate experience with clinical problems appears as an essential element for teaching clinical reasoning [1,16,24]. There seems to be nothing new here, because experience with patients or case reviews for example has always been highly valued in medical education. However, in order to facilitate the development of illness scripts, students must be exposed not to a few very elaborate or complex The cases should be at the appropriate level. On the one hand, students need to have enough knowledge to engage with the cases. On the other hand, the cases must be challenging, demand effort, reach the limits of the students' competence [6,16,24].
A second important issue is what is actually the practice with clinical problems. Studies from various fields [28][29][30][31] have shown that what students can learn from practice with problems depends on what they are requested to do with them [24].

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The student needs to actively engage in problem solving and actively process its information. There are substantial advantages in using instructional approaches that lead the student to compare similarities and differences between problems, identifying for example structural differences Instructional approaches based on these principles have shown to be effective in many experimental studies over the past few years. For example, 'self-explanation', a learning strategy originally studied in other areas, requires students to diagnose clinical cases by explaining to themselves the pathophysiological mechanisms underlying those manifestations [35]. In several studies, students who used self-explanation during practice with problems made more correct diagnoses when they encountered similar cases in the future than students who had used more conventional approaches, such as making differential diagnosis [36][37][38]. Another strategy, 'deliberate reflection' , makes it possible to compare and contrast clinical cases by following a systematic procedure. Deliberate reflection has been shown, in several experimental studies, to be more effective in developing diagnostic competence than more conventional approaches [39][40][41].
At this point, a teacher may be wondering how this evidence generated by research could be incorporated into teaching practice. In many schools, the teaching of clinical reasoning is still based on the assumption that the ability to reason clinically is acquired 'naturally' when students begin to apply the previously acquired knowledge to address patients' problems, observing the teacher as a model. This tradition is changing, perhaps due to the recognition of the limitations of real practice environments for teaching clinical reasoning [24]. In these environments, supervision and feedback are limited, and there is no way to guarantee experience with a wide variety of problems [42,43]. Experience with real patients has a key role in physicians' education and remains crucial to develop several dimensions of professional competence. However, the teaching of clinical reasoning cannot depend solely on the experience with real patients. Many medical schools have therefore created specific programs for teaching clinical reasoning, sometimes starting already in the first years, to ensure that students are provided with an extensive practice with appropriate supervision and feedback [24]. The essential learning resource in these programs consists of clinical cases. There are a wide variety of formats, with programs using written or video cases, others featuring simulated patients, real patients, or even virtual patients, and exercises with cases occurring individually or in groups, in classrooms or clinical settings, face-to-face or online. There is therefore much room for the teacher's creativity, especially because a program of exercises with clinical cases does not necessarily require special resources. Research has shown that the fidelity of simulations, which usually demands more developed technology, does not seem to substantially influence learning [44,45]. Much more crucial seems to be to align the practice with problems with the principles that research over the last decades has shown to be valid.
In summary, research on clinical reasoning in recent decades indicates that there are not reasoning strategies that are specific to the expert physician that could be taught to students.

Notes: Funding
This study did not receive financial support from external sources

Conflicts of interest disclosure
The authors declare no competing interests relevant to the content of this study.

Availability of data and responsibility for the results
The author declares to have had full access to the available data and they assume full responsibility for the integrity of these results.