Previous research has shown that paramedics form intuitive impressions based on limited “pre-arrival” dispatch information and this subsequently affects their diagnosis. However, this observation has never been experimentally studied.
This was an experimental study of 83 Australian undergraduate paramedics and 65 Australian paramedics with median 14 years' experience (Range: 1–32 years). Participants responded to written vignettes in two parts that aimed to induce an intuitive impression by placing participants under time pressure and with a secondary task, followed by a diagnosis made without distraction or time pressure. The vignettes varied the likelihood of Acute Coronary Syndrome (ACS) and measured self-reports of typicality and confidence. Answer fluency, which is the ease with which the answer comes to mind, was also measured.
More participants exposed to the likely pre-arrival vignette recorded a final diagnosis of ACS, than those exposed to unlikely pre-arrival information (0.85 [95%CI: 0.78, 0.90] vs 0.74 [95%CI: 0.66, 0.81]; p = 0.03). This effect was greater in paramedics with more than 14 years' experience (0.94 [95%CI: 0.78, 0.99] vs 0.67 [95%CI: 0.48, 0.81]; p = 0.01). Answer fluency and confidence were associated with the impression, while the impression and confidence were associated with final diagnosis.
The authors have experimentally shown that pre-arrival information can affect subsequent diagnosis. The most experienced paramedics were more likely to be affected.
This is the first experimental study of diagnostic decision-making in paramedics and paramedic students.
