Methods
This prospective cohort study was performed in Cork University Hospital in conjunction with University College Cork in April 2021. The participants were final year medical students from both the undergraduate and postgraduate programmes who had completed their educational curriculum. Students were invited to participate and receive supplementary ECG teaching. The participants were divided into 4 teaching sessions to comply with local public health guidelines which limited lecture theatre capacity at the time. The participants were allocated to their groups by university administrators and the investigators had no influence on this process. Ethical approval was granted by the Clinical Research Ethics Committee of the Cork Teaching Hospitals.
The ECG interpretation teaching was delivered by 3 cardiology trainees. The trainees were doctors with >5 years of clinical experience and at least 1 year of specialty experience. The teaching was delivered as live presentations with an interactive component and ECG examples were shown to illustrate all principles covered. The topics covered included: heart rate, rhythm, cardiac axis, bundle branch blocks, bradyarrhythmias, AV node block, atrial fibrillation, atrial flutter, tachyarrhythmias, acute coronary syndromes and distinctive ECG changes seen in various clinical emergencies.
Standardised examinations were given to all students before and after attending the teaching sessions. The examinations consisted of 10 questions, each with an accompanying ECG to interpret. A short clinical case was provided if necessary for accurate ECG interpretation. The examination format required participants to provide a free hand answer. There were no multiple choice answers. This was designed to reflect ECG interpretation in clinical practice. Two examination versions were used. There were equal numbers of questions on each aspect of ECG interpretation in each version, for instance there were 4 questions on identifying the rhythm in each version. Both versions were judged to be of equal difficulty by the investigators. A different examination version was given before and after the teaching session. The order in which these versions were given was alternated between teaching sessions.
A questionnaire was given to all students on completion of the teaching sessions to assess their confidence in ECG interpretation. Demographic data was taken from the examination papers returned at the end of the teaching sessions.
Statistical analysis was performed by a single investigator with a p value of less than 0.05 considered significant. A paired t-test was used to compare the examination results from before and after the teaching sessions. The null hypothesis of no difference between results was assumed. The association between receiving teaching and answering a question correctly was assessed using the log odds ratio. Subcategory analysis was performed on 7 aspects of ECG interpretation examined. Further subcategory analysis was performed to assess the impact of ECG teaching depending on the participants’ baseline knowledge (pre-course results). The secondary outcome of change in participants’ confidence was assessed using a paired t-test. The null hypothesis of no difference between confidence levels was assumed.