Operational definition of heuristics:
For the operational definition of the Representativeness and Availability heuristics, the study protocol published by some of the authors was used, which analyses the cognitive aspects of the diagnostic process of dyspnoea by primary care physicians,20 and whose definition is described below: (Fig.1)
Representativeness : the final diagnosis of the dyspnoea picture coincides with the first diagnostic impression made by the physician when identifying a new episode of dyspnoea, prior to performing the anamnesis, physical examination or request for diagnostic tests (”this patient is representative of…”). It would be part of what has been called ”gut feeling”,22 hunch or ”first diagnostic impression”,23 identifying the degree of similarity of the sample (the new case) with the population (the set of cases of that specific diagnosis).
A representative heuristic is identified when the first diagnostic impression (FDI) does or does not coincide with the Final or Confirmatory Diagnosis (CD). This definition is consistent with that established by Klayman24 and allows the heuristic to be quantified in real clinical decision contexts.
Availability : inclusion of the final diagnosis of the case of dyspnoea among the list of three possible diagnoses (in order of priority) included in the question of Differential Diagnosis in the case of dyspnoea after anamnesis and physical examination. It would identify the diagnostic options that are most quickly rescued from memory.25 Therefore, there is an availability heuristic when the final or confirmation diagnosis (CD) is included among the three hypotheses of differential diagnosis (DD).
Overconfidence: The doctors were expressly asked what level of confidence (between 0 and 100%) they had in their diagnostic proposal (the ”diagnostic judgment” proposed after performing the anamnesis and physical examination on the first visit facing a new case of dyspnoea). The possible presence of overconfidence in the diagnosis was estimated, if the confidence in the diagnosis was greater than 75% (data that represents the average presence of overconfidence in the subjects of the study).