This study highlights two important points: BLS skill decays rapidly in previously competent medical students, and one-to-one instruction is the optimal way to enhance refresher learning.
The decay in BLS performance worsens as time elapsed since the original BLS training increases, with the pass rate (compliance with ERC BLS guidelines during formal assessment by a trained examiner) decreasing to 34.5% even 1 year following the primary course and declining further thereafter. Such findings highlight that in order to prevent significant skill decay, refresher training should commence at some stage within the first 12 months of initial BLS teaching. Of note, as students in our institution become more senior they move from lecture theatres to clinical placements, and are more likely to be exposed to cardiac arrests in hospital. Many students in their fourth year of study (three years following initial BLS training) receive CPR training in their hospital. This may account for their small improvement in pre-refresher training BLS performance when compared to students 2 years after their initial training.
Our study also investigated the most effective method of refresher teaching. We found that one-to-one training between student and instructor served as the most effective means, with post-refresher training compliance during skill assessment meeting ERC guidelines in 100% of individuals re-assessed. The use of an information sheet alone improved BLS performance, albeit to a lesser-degree than one-to-one training, and sole use of video-assisted training showed an even smaller improvement in BLS performance (non-significant).
Each method of refresher training carries advantages and disadvantages. Although one-to-one teaching incurs the best improvement in post-refresher competency, it is the most resource-heavy option, requiring the presence of suitably qualified instructors. In our study, we trained students in a 1:1 ratio with instructors - larger instructor to student ratios may allow greater efficiency, and reduced resource use. That said, larger group sizes increase risk of Covid-19 exposure, and safely moving large groups into and out of training venues whilst practicing social distancing will be challenging.
In contrast, video-assisted training with the opportunity for self-practice requires less resource, and is much less likely to encourage Covid-19 transmission. The use of a pre-recorded video offers a reproducible alternative to one-to-one instruction. Large numbers of students are able to watch the video at once and resources could easily be disseminated via an online platform for quick and easy access. Use of technology in this way may be a scalable refresher training option for centres with limited resources or larger cohorts. Disadvantages of video-assisted training include the lack of instructor interaction with students and the subsequent inability to ask questions in order to further understanding and consolidate knowledge. Similarly, without having a qualified instructor present to observe practice, students are unable to receive feedback on their performance and they are left to self-determine their competence. In our study, video-assisted refresher training as a sole modality failed to meaningfully improve candidates’ performance. Though high quality, the British Heart Foundation’s Heartstart video we used during training only runs for 6 minutes and is not interactive – it is intended to be followed by group or individual hands-on practice. An alternative interactive option is the Lifesaver video produced by the Resuscitation Council (UK). (23) A randomised controlled trial comparing Lifesaver to face-to-face training in school children demonstrated broadly similar performance following initial training, though combination of face-to-face training and Lifesaver outperformed both modalities in isolation. (24) The British Heart Foundation has developed an alternative video curriculum titled “Call Push Rescue” which is designed to be displayed in a classroom with candidates performing CPR together, using their own individual manikins. (25) It was beyond the scope of this study to compare different video modalities, though it is possible candidates’ performance would have been different had we chosen to use either Lifesaver or Call Push Rescue.
Participants who received refresher training via a written information sheet to read showed significant improvement in their post-refresher BLS performance, albeit to a lesser extent than seen with one-to-one training. One implication of this method of refresher training is that no Laerdal Little Anne® manikins are required. On one hand, this potentially puts candidates at a disadvantage as they have no opportunity to practice hands-on CPR. On the other hand, it may be a suitable option for those centres who have very limited resources and funds, where manikins are reserved for de novo BLS training only.
Overall, BLS refresher training involving one-to-one teaching with a qualified instructor is the optimal way of refreshing BLS skill in terms of pass rates, yet uses the most resources and therefore may not be suitable for all centres. Given the current Covid-19 pandemic, it may be undeliverable in many contexts. Using video-recordings and written information sheets in combination with - or in lieu of - one-to-one refresher training may allow rapid, effective skill refreshment whilst minimising risk of Covid-19 transmission. It is feasible that skill retention following different refresher training modalities may differ – for instance, participants re-trained using video assisted self-learning may require more frequent refresher sessions than those re-trained using instructor led face-to-face methods. The optimum window in which to schedule further refresher training following each modality of refresher training is a topic for future study.
Our study has several important limitations. Firstly, despite achieving our recruitment target from a power calculation based on pilot data, our relatively small sample size (42) limits the study’s generalisability. There are unequal numbers of participants in each refresher group given the increased instructor resource required to run one-to-one training. The use of the same examiner to assess participants both pre- and post-refresher training introduces the risk of observer bias, limiting the value of comparisons drawn from both pre- and post-refresher training. However, blinding with regard to group allocation means that methods of refresher training can be safely compared. Some of the improvement in scores between the initial and post-refresher assessment may be attributable to practice participants obtained in sitting the initial assessment itself, though this would not explain differences observed between groups. Finally, the study is temporally limited with regards the amount of time elapsed since participants’ original BLS training. As such, our results may not be generalisable to the wider population outside of the medical student cohort, or to those for whom a greater amount of time has elapsed since their initial BLS training.
Future research should aim to recruit a more representative cross-sectional sample of the overall lay population, specifically including non-healthcare students, members of the public and/or school children. Although our study only investigated three methods of refresher training, it still provides a valuable comparison that highlights clear differences in effectiveness of these methods. This study is the first of its kind on this subject, and clearly demonstrates that BLS skill decays in medical students after as little as one year. Additionally, it has shown the variation in efficacy of three different refresher teaching methods that are simple, adaptable and inclusive.