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.