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).