Epistemic tasks in clinical decision-making

The goal of clinical decision-making is to compose a diagnosis and treatment plan that is suitable to the patients’ personal situation, signs and symptoms and based on relevant and reliable evidence. Computer-based clinical decision support systems (CDSSs) are expected to improve clinical decision-making by making it faster, cheaper, less prone to human errors or more precise.6,12 In practice, clinician and computer can complement each other, each having different capacities to perform crucial but different epistemic tasks that together add up to a diagnosis or treatment plan. In order for CDSS to support clinical decision-making, the capacities of human and artificial intelligence need to be maximally utilized and aligned to each other. First, we will analyse which epistemic tasks can be better done by CDSS, and which by clinicians.

Clinical decision support systems

CDSS makes use of artificial intelligence (AI) that is designed to mimic or improve clinical decision-making. Two broad categories of AI uses in CDSS are usually distinguished:6,8,10‘knowledge-based’ AI (also called rules-based expert systems9) and data-driven AI. Knowledge-based AI systems have been in use since the late 1970’s, and aim to replicate human decision-making by programming the rules experts employ when they make decisions in their field in computational terms.10 As such, a knowledge-based system can best be thought of as a database of ‘best-practice’ rules that can be employed to find the most suitable procedure (e.g. examination or treatment) for an individual patient.9 The ‘logic’ employed by the system can be represented as formal rules, such as “when a patient with disease X also has symptom Y, use medication Z.” As such, the ‘reasoning’ employed by the system to arrive at a specific advice, can easily be backtracked and evaluated.
The data-driven use of AI has developed significantly over the last decade, and employs statistical machine learning algorithms to abstract patterns from large amounts of data. In the so-called supervised machine learning to develop a CDSS, the machine learning system is fed with a large amount of data about a group of patients labelled with the clinical diagnosis by medical professionals, the so-called ‘training dataset’. In this learning-phase, the CDSS learns to ‘recognize’ the patterns (represented by a ‘model’) in the training-set that fit best with the correct diagnoses. When a new case is entered into the system, it will use the patterns that it has inferred from the ‘training-set’ to make a prediction about an individual case.10 The ‘logic’ employed by this type of CDSS is (rather than rule-following as in knowledge-based CDSS), based on comparisons between cases, such as “other patients with disease X and symptom Y have benefited from using medication Z”.9 Because data-driven CDSSs are often trained using data from thousands of cases or more, a multitude of the amount of cases that a physician sees in a lifetime, these systems are able to detect very subtle and complex patterns in the data (e.g. Savage 202012). However, unlike knowledge-based AI, the decision made in a data-driven CDSS cannot easily be explained,6 which leads to critical questions about the robustness, explainability, reliability and accountability of these types of systems.10

Epistemic tasks by CDSSs: statistical reasoning and pattern recognition

Knowledge-based systems can be thought of as a database of best practice in terms of rules, such as evidence-based guidelines. The advantage of an automated system is that it can use the patient’s individual characteristics to find the most suitable guidelines and procedures. Data-driven systems do not use this type of rule-following, but have other capacities. Boon (2020) has analysed the epistemic tasks that machine-learning algorithms are capable of doing. According to her categorisation of epistemic tasks, machine-learning algorithms can match input data (e.g., an image or a set of data points such a clinical signs and symptoms) with similar cases in their database; interpret input data as belonging to a specific category, defined by humans or by a machine-learning algorithm;diagnose a set of input data as probably belonging to a certain class and from that infer other properties of the target;structure large amounts of data to find patterns, correlations and causal relations; calculate in a way that outperforms humans; and simulate complex dynamic process.15 In short, computers outperform humans when it comes to deductive and inductive reasoning, and are also rapidly improving at recognizing patterns and images. As such, the medical field in which CDSS has been most successful is radiology (and also other types of visual data, e.g., electrocardiograms), detecting conditions such as tumours and other lesions in large amounts of imaging data in short amounts of time.3,12,16 Furthermore, as humans are notoriously bad at statistical reasoning (for example, estimating odds based on quantitative information, see e.g. Kahneman 201117), CDSS can provide a valuable contribution to the process of clinical decision-making by comparing the information clinicians do have about a patient with the information about other (groups of) patients in the database of the CDSS. And, based on similarities with other cases, use this to make suggestions about the diagnosis and predictions of possible outcomes of a certain treatment.
However, as Boon contends, in most professional fields, the goal of performing epistemic tasks such as those listed above, is not (only) toidentify the most refined classification, or the most perfectly fitting class. Rather, the epistemic purpose is knowing how to control or interact with the targeted phenomenon (e.g., the symptoms or illness of a patient), which requires relevant understanding to begin with. Translated to clinical practice, the goal of performing epistemic tasks is to device interventions that contribute to making the correct diagnoses or actions that alleviate the patient’s symptoms or benefit the health of patients. This requires human intelligence, for example to collect, review and process data before it can be entered into the CDSS, to judge which information is relevant, and to evaluate the outcomes. In the next section, we will therefore elaborate on the epistemic tasks of clinicians.

Epistemic tasks by clinicians: constructing a ‘picture of a patient’

In an earlier paper, we have argued that good quality decision-making involves highly complex and refined ways of clinical reasoning, of which several examples can be given.11 First, while considering the available information, clinicians continuously deduce and verify options – this is because they understand, for instance, that one effect can have multiple causes and one cause can have multiple effects. Second, in addition to algorithmic and deductive, rule-based reasoning, “creative” thinking and nuanced styles of reasoning are an important part of good clinical decision-making. For example, clinicians make use of case reports, descriptions of individuals or small groups with ‘surprising’ or ‘problematic’ symptoms18 to come up with a possible diagnosis. Or they use narrative techniques to logically integrate all available information.19Third, an understanding of the mechanisms of a disease is necessary to translate general statistical information to the situation of individual patients.20,21 Finally, Khushf (1999) argues that the diagnostic process involves both determinative judgement(bringing a particular instance under a general concept) andreflective judgement (beginning with a particular and seeking out a concept). When a patient visits a medical professional, this expert develops an initial insight into what is the matter with that patient (a set of possible diagnoses based on integration of the patient’s specific signs and symptoms), thus providing a reflective judgment. A diagnosis is then established by a determinative judgment, i.e. by determining under which diagnosis the observed (but usually incomplete) signs and symptoms fit best.22 These epistemic tasks (i.e., making these judgments) cannot be outsourced to a machine learning system because it concerns reasoning which is not algorithmic or statistical. It is therefore important that clinicians have developedexpertise , which includes tacit knowledge andcognitive skills , enabling them to draw up a diagnosis or treatment plan, despite incomplete information and uncertainty.14 In addition, clinical decisions are often based on the integration of pieces of evidence generated by medical professionals with different expertise. Interpreting and adjusting the pieces of evidence into a coherent diagnosis takes place in interaction between different experts. This requires specific skills to enable the (social and epistemic) interaction between experts, i.e. opening up and explaining their deliberation to others and justifying to others how they come to a certain interpretation, while being sensitive to deliberations and interpretations from others.23

Epistemological responsibility

In the previous sections we have analysed which epistemic tasks concerning clinical decision-making CDSS are well-equipped to perform, and which epistemic tasks require human intelligence. Additionally, we need to explain why clinicians remain responsible for the decisions made in clinical practice, for which we give epistemological reasons. Earlier, we have pointed out that clinicians have the epistemic task to develop a ‘picture’ of a patient that is logically coherent and consistent with contextual and personal information as well as general, scientific and statistical knowledge.11 Clinicians together with the patient, and usually in collaboration with other medical experts, use this ‘picture’ in their clinical reasoningabout the diagnosis and treatment of the patient. Usually this involves a process in which the clinician, based on the formed picture so far, forms hypotheses about the illness and asks new questions. This leads to additional diagnostic tests and searches in medical literature, which in turn produces new information that is added to the picture, leading to new hypotheses and questions, etc. In other words, the clinician enters into a search process (exploration and investigation) in which new information is adapted and integrated with the existing information. In this process, clinicians continually update the ‘picture’ they have of their patients, and use it to direct the next step in the search process.
Collecting, interpreting, adapting and integrating the data into a coherent picture involves a considerable amount of choice, deliberation and justification by clinicians, for example about the relevance and quality of the information. Clinicians are epistemologically responsible for these choices and deliberations, although CDSS can help by providing information in ways suggested above. As a consequence of this epistemological context, clinicians are responsible for the way they construct and use the ‘picture’ of the patient. This also means that clinicians need to be able to explain and justify their decision-making. We have therefore argued that clinicians should consider themselvesepistemologically responsible to produce good quality knowledge about their patients.11 The idea of epistemological responsibility is based on Lorraine Code’s (1984) insight that cognitive agents (such as doctors) have an important degree of freedom when it comes to reasoning (e.g., in deciding which information is relevant and which not in their argument; and how to interpret specific information) and that they are accountable for how they deal with this freedom.24 Therefore, in contrast to passive information processors (such as CDSS or other algorithms) that are at best reliable and fast, clinicians, as cognitive agents, should be evaluated in terms of responsibility. With the notion of epistemological responsibility we aim to grasp the specific epistemic challenges faced by clinicians to perform epistemic activities involved in clinical decision-making concerning diagnosis and treatment. As CDSSs outperform clinicians in some specific, well-defined tasks, their applications may still comply with the epistemological responsibility of clinicians. This requires, however, that the CDSS is fitted into the clinical reasoning process , and that the clinician is still able to take responsibility for this process. In Section 3 we will analyse what this means for the development of CDSSs, the required properties of a CDSS, the required skills of the clinicians and the role that a CDSS can play in clinical reasoning.