Objectives Script concordance tests (SCTs) can be used to assess clinical reasoning, especially in situations of uncertainty, by comparing the responses of examinees with those of emergency physicians. The examinee's answers are scored based on the level of agreement with responses provided by a panel of experts. Emergency physicians are frequently uncertain in the interpretation of ECGs. Thus, the aim of this study was to validate an SCT combined with an ECG.

Methods An SCT-ECG was developed. The test was administered to medical students, residents and emergency physicians. Scoring was based on data from a panel of 12 emergency physicians. The statistical analyses assessed the internal reliability of the SCT (Cronbach's α) and its ability to discriminate between the different groups (ANOVA followed by Tukey's post hoc test).

Results The SCT-ECG was administered to 21 medical students, 19 residents and 12 emergency physicians. The internal reliability was satisfactory (Cronbach's α=0.80). Statistically significant differences were found between the groups (F_0.271=21.07; p<0.0001). Moreover, significant differences (post hoc test) were detected between students and residents (p<0.001), students and experts (p<0.001), and residents and experts (p=0.017).

Conclusions This SCT-ECG is a valid tool to assess clinical reasoning in a context of uncertainty due to its high internal reliability and its ability to discriminate between different levels of expertise.