To evaluate alternative teaching methods for BLS, we performed a study comparing the widely practised and accepted 4-step approach with the newly developed media-supported approach (MSA) in a group of laypersons. This controlled trial tested if the new approach could achieve comparable performance concerning the acquisition of BLS skills.
The main result of this study is that the MSA for resuscitation training compared to the established methodology leads to comparable retention of skills both one week after the training and six months later. Both educational approaches result in comparable practical performance. Compared to baseline testing, the one-week evaluation showed a significant improvement for various parameters, including correctness of the initial assessment algorithm and no delay in CPR initiation; additionally, no significant differences between groups were identified for the mean compression depth and mean compression rate. Compared to the standard group, after one week, the participants in the MSA group had significantly more compressions that were “too deep” and fewer that were “too shallow”. It is promising that the MSA group tended to have deeper as opposed to shallower compressions. Hopefully, this fact will result in superior performance according to the newly recommended range for compression depth (50 to 60 mm instead 38 to 51 mm) in the 2010 ERC Guidelines . After six months, the MSA group did not exhibit significantly different results concerning practical performance data. In fact, correctness of the initial assessment algorithm (>60% correct) tended to be recalled better in this group (S: 83% vs. MSA: 81%; p = 0.933); the compression depth was also superior (S: 47% vs. MSA: 56%; p = 0.7965), but the difference was not statistically significant.
Furthermore, the participants reported significant improvements in self-confidence concerning the BLS algorithm and ECC performance in both groups. There were no significant differences in the self-confidence levels of participants regarding the observed skills between the groups at any time.
Our findings are consistent with other studies that have investigated using video-based teaching in CPR. Lynch et al. reported that a 30-min self-instruction program enables laypersons to become as good at performing CPR as laypersons trained with an instructor .
The high efficiency of this newly established MSA training method is based not only on equivalent practical skills of ECC but also on results regarding the individual self-assessments of participants between the groups, which were also equivalent. Analysis of BLS training needs to be undertaken from different points of view; thus, a 360-degree investigation should be the final goal.
Studies regarding the willingness of laypersons to perform bystander CPR with prior BLS training  confirm this finding. Similar studies have reported that laypersons with prior BLS training were more confident with CPR initiation  and were more willing to perform bystander CPR [13, 14]. According to this finding, the MSA training method may lead to the same bystander rate as the traditional 4-step approach.
The typical 4-step approach method is widely accepted and used by various organisations that teach, similar to the ERC (1;2;4) or the American Heart Association . This approach is dependent on qualified instructors who need to be taught and certified by extensive procedures. Not every organisation, company or medical institution has sufficient resources to provide enough instructors for teaching large groups of laypersons or medical staff. In addition, insecurity and variation in the quality and standardisation of the instructors will always exist. Importantly, almost 20 years ago, the instructor was identified as one possible reason for the poor retention of skills . The modified “media-supported 4-step approach” could represent one possibility for enhancing the range of training methods. Usage of media, including video, offers different capabilities for involving the learner in a self-directed learning process as part of a blended learning concept. Bobrow et al. showed that usage of an ultra-short hands-only CPR video improves CPR practical skills. This investigation revealed evidence that simply the usage of short educational videos has an impressive effect on the acquisition of ECC skills . If new technologies are used, such as videos or portable devices, learners can refresh themselves as often as needed. Our results regarding the retention of skills and usage of video-based teaching/training show that this tool could be useful and effective. In addition, Einspruch et al. showed that the retention of ECC skills is poor two months after training . It is possible that self-instructed video-based training could be very useful for refreshing important CPR skills.
Based on these results, it seems worthwhile to establish a concept that integrates videos for more self-directed BLS learning. Different study groups demonstrated that teaching methods, such as self-directed learning using video-based BLS self-instruction, is an appropriate approach for special groups of learners [18–20]. A study by Nishiyama et al. showed that watching a CPR instruction video as a self-directed learning tool encouraged people to perform CPR and to use an automatic external defibrillator. Moreover, the study showed that practical training in BLS is indispensable .
Further investigation should include the implementation of interactive learner software installed on portable devices. Methods such as MSA could support the shift from teacher-centred learning to learner-centred course concepts. However, there is no evidence that the typical 4-step approach leads to superior learning outcomes. Recently published work by Greif et al.  showed no advantage for skills acquisition compared to a traditional 2-step approach, as embodied by the “see one, do one” approach, for percutaneous needle-puncture cricothyroidotomy. Another study group also reported similar results in comparing the 4-step approach with a 2-step method for laryngeal mask insertion . Indeed, it might be questionable if these results are transferable to a comparably more complex “skill” (i.e., ECC) within a complete algorithm such as BLS. In fact, Greif et al. postulated that “…further investigations in more complex skills under different settings might show the superiority of the 4-stage approach …”.
Our results show that the investigated MSA method of teaching BLS, specifically as it pertains to ECC skills, is equivalent to the typical instructor-based 4-step approach. The quality of ECC performance was at the same level both after the training and six months later. Obviously, the MSA offers an additional alternative for teaching ECC among BLS skills, but more investigation into these findings is needed.
Furthermore, our study could demonstrate that this type of methodological approach is feasible and accepted by participants. Looking at the questionnaire data, the majority of participants belonging to the MSA group completely agreed that the BLS skills were demonstrated “explicitly” and that they were provided with sufficient explanations of the topic at hand. Only a minority would prefer to have a lecture on the topic.
However, more data need to be collected to determine how effective and efficient these methods are for improving the survival rate of patients with cardiac arrest.
Regarding possible limitations, the observed study group was not equally distributed with respect to gender (69% female), but the distribution was comparable between groups. Additionally, the participants were not chosen at random but rather represent inexperienced laypersons with regard to emergency medical issues because German medical students start medical school immediately after graduation from secondary school without any prior preparation. However, based on the reported baseline results, it is suitable to state that our participants did not differ; therefore, groups are comparable. Like previous studies, we argue that the participants are laypersons concerning CPR and are not representative of or similar to health-care professionals [21, 22].
Furthermore, in this kind of simulation study, each manikin used is unable to mimic a human, especially when representing an unconscious, breathless and pulseless victim. Nevertheless, the use of manikins as a tool for testing is appropriate, and multiple studies have previously described relevant methodologies [23–28].
A methodical limitation might be the dropout rate by the six-month evaluation; the main reason for this is that many participants had other mandatory appointments during these evaluation periods. We are aware that, in general, voluntary participants might initiate a positive selection bias, such that these volunteers would often outperform others . However, as described in the literature [30, 31], all of our study groups were exposed to this bias; therefore, they are still comparable.