The study was conducted at the Faculty of Health Sciences, University of Maribor (Maribor, Slovenia) between March and May 2023. The study was registered in ClinicalTrials.gov (NCT05784675). The study protocol was written in accordance with the Consolidated Standards of Reporting Trials of Electronic and Mobile Health Applications and Online Telehealth (Multimedia Appendix 1) [32].

Ethical approval was obtained from the Slovenian National Medical Ethics Committee (0120-157/2018), and permission to conduct the study on the faculty premises was obtained from the Faculty of Health Sciences, University of Maribor. During an oral presentation of the study, nursing students were informed about the research protocol, and written consent was obtained afterward. Data confidentiality and anonymity were maintained throughout the study. Participants were rewarded for their participation in the study with a free beverage from a vending machine and a copy of the Game Changer painting by street artist Banksy [33].

All nursing students enrolled in the first-degree nursing program at the Faculty of Health Sciences, University of Maribor, during the 2022-2023 academic year were invited to participate in the study. Inclusion criteria to participate in the study were written informed consent, an age of at least 18 years, and ability to perform adult BLS on a manikin (eg, without injury). Our study had no exclusion criteria.

This study had a randomized wait list–controlled design, where nursing students were randomly assigned in a 1:1 ratio using a computer-generated list (Microsoft 365 Excel Enterprise) to either a MOBICPR intervention group (MOBICPR-IG) or a wait-list control group (WL-CG). The WL-CG was a group of nursing students who were assigned to a wait list and received the intervention (MOBICPR game for playing at home) 2 weeks after the MOBICPR-IG.

All assessments of the participants’ theoretical knowledge of and practical skills in adult BLS were conducted 3 time points: baseline, 2-week follow-up, and 4-week follow-up. At the baseline assessment, the investigators first collected demographic data from the participants. Additionally, the participants were questioned about their willingness to assist both family members and strangers during OHCA with CPR. Prior to practical skills in adult BLS, participants’ the theoretical knowledge of adult BLS was assessed using a questionnaire with 33 single- and multiple-choice questions [25,34-36] on an open source online survey app called 1ka (Ljubljana, Slovenia); see Multimedia Appendix 2. A back-translation approach was used for translating the questionnaire into the Slovenian language.

Prior to the assessment of adult BLS practical skills, each participant was given a scenario based on OHCA to read (Multimedia Appendix 3). After reading the scenario, the participants were given a smartphone for calling emergency services at the time of performing adult BLS. Instead of dialing the actual emergency number, the participants used the contact stored on the smartphone as 112 (ie, the Slovenian emergency number). After the call was placed by each participant, the investigator answered the phone and conducted a simulated dispatcher conversation [37]. The investigator was a registered nurse working at the local medical dispatch center. Each participant performed 2-minute adult BLS without any help in a staged kitchen on a manikin (Resusci Anne Quality Cardiopulmonary Resuscitation [QCPR], Laerdal Medical) using an AED (Defibtech, Trainer AED). The staged kitchen was a space surrounded by mobile walls in the hospital’s simulated room. A photo of a kitchen was projected onto the wall, and below it was an electric stove with a pot full of water (Figure 1). In each adult BLS scenario, the investigators turned on the electric stove, and the scenario began when the water started to boil, simulating a hazard. The kitchen was chosen because the majority of OHCAs occur there [38].

After 2 minutes of performing adult BLS, each participant received assistance from an outside person bringing in an AED and taking over CPR. The adult BLS practical skills of each participant were recorded using a Sony Handycam 4K AX53 camera and an Apple iPad Pro 3rd generation tablet. Two investigators with a background in emergency medicine and teaching laypersons adult BLS assessed the participants’ practical skills in adult BLS using a modified checklist [25,36,39] according to the ERC BLS guidelines of 2015 [40] and 2021 [34], with a total of 34 items (Multimedia Appendix 4). A back-translation approach was used for translating the checklist into the Slovenian language. Numerical data from the SkillReporter for Tablet version 1.4.1 (Laerdal Medical) app installed on a Samsung Galaxy Tab S6 Lite tablet was also included in the evaluation of the participants’ practical skills in adult BLS. Investigator debriefing was not conducted following the assessment of the participants’ adult BLS theoretical knowledge and practical skills. Instead, each participant (from MOBICPR-IG at baseline and from WL-CG 2 weeks after baseline) first played the MOBICPR game [31] on a Samsung Galaxy A13 smartphone in front of the investigator and then received the same smartphone to play at home. The objective of the MOBICPR game is for participants to interact with a smartphone using gestures (eg, tapping) and actions (eg, talking) to help save the life of a virtual patient with OHCA by performing evidence-based adult BLS. The MOBICPR game is based on the 2021 ERC BLS guidelines [34], and the BLS content was developed using the Delphi process. The patient’s chance of survival in the MOBICPR game reduced with each incorrect interaction by the participants. At the end of the MOBICPR game, each participant received a total score in the form of a gamification feature that corresponded to the risk of survival (score>50% meant the patient survived) [41]. Gamification, defined as “using game design elements in non-game contexts,” has been introduced into nursing education to promote engagement using features such as leaderboards, rewards, badges, and avatars [22]. After playing the MOBICPR game as much as they wanted for 2 weeks, participants in the MOBICPR-IG returned the smartphones. Participants in the W-CG then received the smartphones and followed the same protocol as participants in the MOBICPR-IG, that is, they played the MOBICPR game in front of the investigator before taking the smartphone home. Participants in the W-CG also returned the smartphones after playing the MOBICPR game at home for 2 weeks. Additionally, at the study’s conclusion, each participant was asked an open-ended question regarding the number of family members or friends with whom they shared the MOBICPR game for playing.

The primary outcomes were (1) assessment of the participants’ theoretical knowledge of adult BLS using a questionnaire with a total maximum score of 33 points, where each correct answer was awarded 1 point (Multimedia Appendix 2), and (2) assessment of the participants’ practical skills in adult BLS using a checklist with a total maximum score of 39 points (Multimedia Appendix 4).

The secondary outcome was a summary score of high-quality CPR components: (1) a chest compression (CC) rate of 100-120 beats per minute (bpm), (2) a CC depth of 50-60 mm, (3) CC fraction>80%, and (4) a rescue breath volume of 500-600 mL (Multimedia Appendix 4). All measures were taken as mentioned earlier [16,23,27,28]. A total QCPR score was also included, ranging from 0% to 100%. More detailed information about software scoring is available on the Laerdal Medical website [42]. Both primary and secondary outcomes were measured at 3 time points: baseline, 2-week follow-up, and 4-week follow-up.

Statistical analyses were conducted in October and November 2023. Data were analyzed using the R statistical programming language (R Foundation for Statistical Computing). The data presented in the summary table were prepared using frequency analysis, which also included a chi-square test to assess the similarity of the distribution between the intervention and control groups. Theoretical knowledge and practical skill assessments were averaged at the item level and subsequently analyzed using nonparametric statistical tests (Wilcoxon paired-sample test and Mann-Whitney U test) as the normality of the distribution was violated. As nonnormal distribution might represent a problem when calculating mean values, violin plots were also used for the purpose of visualizing aggregated scores due to their ability to visualize the distribution of the data. P<.05 was considered statistically significant. Effect size (η²) values >0.1 represented a small effect; 0.3, a moderate effect; and ≥0.5, a large effect. Continuous variables were analyzed according to the Gaussian distribution and reported as the mean (SD) or the median (IQR), whichever was appropriate.

Of 124 nursing students, 80 (64.5%) declined to participate in the study and 44 (35.5%) were enrolled into the study. At follow-up, 1 (5%) of the 22 participants in the WL-CG dropped out. In the end, 43 (98%) of 44 participants were included in the final analysis (Figure 2).

The mean age of the participants was 19 (SD 0.6) years, 38 (88%) were female, 35 (81%) had a background in health care and nursing education, 32 (74%) had an iOS smartphone, and the self-reported mean daily time spent on the smartphone was 3.8 (SD 1.2) hours (Table 1).

All participants had received some previous adult BLS training. However, only 2 (5%) had witnessed a cardiac arrest. Most of them (n=38, 88%) had already performed CCs on manikins, but only a few had also been giving rescue breaths (n=12, 28%) and used any kind of AED (n=13, 30%). All participants (n=43, 100%) expressed a willingness to assist a patient with OCHA and perform adult BLS. In addition, they all expressed a willingness to perform mouth-to-mouth resuscitation on a family member or acquaintance. However, only about half of them (n=19, 44%) were willing to do the same for a stranger. The predominant concern for not administering rescue breaths to unknown individuals was the uncertainty regarding the patient’s medical history and the risk for infectious diseases, as cited by 22 (92%) of the 24 (56%) participants who expressed reluctance. On average, each participant introduced and shared the MOBICPR game with 3 (SD 2) family members or friends for trial and play.

To assess the differences between the 2 groups at all 3 observed time points, we calculated the cumulative scores of adult BLS theoretical knowledge and practical skills for both groups.

Figure 3 shows that playing the MOBICPR game at home for 2 weeks improved the overall adult BLS theoretical knowledge (median gain of 4 points, IQR 3, η²=0.113, P=.005) and practical skills (median gain of 4 points, IQR 7, η²=0.05, P=.04). However, in the WL-CG, which waited for 2 weeks to play the MOBICPR game at home, the theoretical knowledge of adult BLS improved by 2 points (IQR 4, η²=0.302, P=.001), whereas the practical skills in adult BLS increased by 3 points (IQR 3, η²=0.018, P=.14). In the MOBICPR-IG, after 2 weeks of not playing the MOBICPR game at home, the retention of theoretical knowledge gained an additional 2 points (IQR 2, η²=0.019, P=.13) and practical skills gained 3 points (IQR 3.75, η²=0.122, P=.003) compared to the 2-week follow-up.

To focus on the impact of playing the MOBICPR game on adult BLS theoretical knowledge and practical skills, we observed participants in both groups and calculated the difference in the cumulative points for both groups after they played the MOBICPR game at home for 2 weeks.

As demonstrated in Figure 4, in the WL-CG, only 3 (14%) participants improved their theoretical knowledge by ≥5 points and only 6 (29%) study participants who achieved this kind of improvement in the adult BLS practical skill score. In contrast, in the MOBICPR-IG, 9 (41%) participants improved their score by at least 5 points in both adult BLS theoretical knowledge and practical skills. The difference in improvement between the MOBICPR-IG and the WL-CG was not significant in practical skills (η²=0.021, P=.45), while in theoretical knowledge, we observed a statistically significant difference (η²=0.268, P=.04).

To obtain more detailed insight into the improvements due to playing the MOBICPR game, we observed the differences in item-level scores before and after playing. Table 2 compares the participants’ scores on questions used to test their theoretical knowledge. It is evident that there were notable differences in most items following engagement with the MOBICPR game. Of 33 scores, 13 (39%) decreased during MOBICPR game playing. For example, the score on question 3 (What is the second thing we check in a patient with cardiac arrest?) improved notably after MOBICPR game playing at home (P=.001). In contrast, the score on question 16 (You are alone. Will you go for the AED if it is 100 m away?) did not improve after MOBICPR game playing at home (P=.103).

Similarly, in the item-level score differences for practical skills, in 7 (21%) of 34 items, a significant increase was calculated (Table 3). For example, the score on item 1 (Approaches the patient safely) improved after MOBICPR game playing at home (P=.001). In contrast, the score on item 2 (Checks responsiveness: shouts and shakes the patient) did not improve after MOBICPR game playing at home (P=.81).

Table 4 shows a comparison of the high-quality CPR components between participants before and after MOBICPR game playing at home for 2 weeks. There were notable differences in the median (IQR) of the total QCPR score for MOBICPR game playing at home for 2 weeks for the MOBICPR-IG (before: median 41 (IQR 54); after: median 70 (IQR 41); P=.011). There was no difference for the MOBICPR-IG after not playing the MOBICPR game at home for 2 weeks.

In this study, playing the MOBICPR game at home for 2 weeks improved the theoretical knowledge of adult BLS in the participants but little their practical skills. These outcomes were expected, considering that the MOBICPR game was designed primarily to impart theoretical knowledge of adult BLS, rather than providing hands-on practice with an actual BLS manikin. To the best of our knowledge, only 2 studies have used data collected from manikin software to evaluate the practical parts of adult BLS as we did [27,28]. We observed in our study population that both the CC rate and the CC depth remain within the margins of the current ERC recommendation [34]; in comparison to our results, in the 2 studies [27,28], both the CC rate and the CC depth dropped below the margins after serious smartphone game playing. These 2 studies [27,28] also presented the total QCPR scores, and where our scores improved compared to theirs. Consequently, we recommend considering the MOBICPR game as a supplementary educational tool in future BLS course formats that incorporate immersive technologies [43,44] for retention of adult BLS knowledge.

In evaluating study participants performing adult BLS on a manikin, we observed 5 learning points (all reported in Tables 2 and 3), which could be useful for debriefing topics after BLS courses. Initially, a large number of participants struggled with checking the manikin’s response as it lay face down. Some checked the response without turning the manikin onto its back, while others did so with the manikin still face down. After playing the MOBICPR game at home, only a minority checked the response after turning the manikin onto its back. Studies show that two-thirds of all patients are found in positions unsuitable for performing CCs, such as the recovery position [45]. The second learning point concerned the right time for chest exposure during CPR. Many participants removed the clothing before looking, listening, and feeling for signs of breathing, while others did so before applying AED electrodes to the manikin’s bare chest. Studies indicate that exposing the chest during CPR can improve the rescuer’s ability to locate the center of the patient’s chest, leading to more effective CCs and reducing the risk of inaccurate compressions [46]. The third point was about shouting for help. A recent study revealed that almost all European BLS instructors teach laypersons to shout for help [47], even though it was removed from the ERC BLS guidelines [34,40]. Despite playing the MOBICPR game at home, the participants still tended to shout for help before calling emergency services. As a fourth point, we noticed that some participants attempted to multitask by calling the dispatcher and performing CCs simultaneously. This practice resulted in lower-quality CCs, as the focus was divided between providing information to the dispatcher and maintaining the 30:2 CC-to-rescue-breath ratio. Generation Z, like the participants in our study, tends to multitask and is more engaged in independent work [48]. Considering this insight, we are re-evaluating the recent ERC BLS guidelines, particularly their recommendation to activate the speakerphone or another hands-free feature on a mobile device before promptly initiating CPR [34]. Finally, we observed that almost all study participants failed to ensure safety before defibrillation when using an AED on the manikin. Issues arose before pressing the shock button, either because they did not check whether someone was touching the manikin or because they pressed the shock button prematurely. This highlights that using an AED is not intuitive for laypersons, as studies suggest, and special training should be considered [49].

The International Liaison Committee on Resuscitation provides a scientific statement on teaching laypersons adult BLS and suggests using TEL, such as serious smartphone games, to engage, motivate, and educate children and adolescents in saving more lives [34]. Several legitimate smartphone games have been identified as suitable for teaching adult BLS, but their content is questionable because it does not follow current BLS guidelines [50,51]. Moreover, most of them teach only hands-on CPR. Some also include ventilation and AED use [51]. However, the MOBICPR game was developed based on recent ERC BLS guidelines [34] and includes all the recommended BLS steps. In a recent MOBICPR study, students agreed that it was beneficial to play the MOBICPR game before practicing adult BLS on a manikin [41]. They also highly rated the usability of the MOBICPR game for providing adult BLS theoretical knowledge and practical skills. The results show that the MOBICPR game could be a novel, interactive, evidence-based BLS educational tool for playing at home after adult BLS training [41,52]. Moreover, our study revealed that the MOBICPR game could be an effective method for enhancing bystander willingness and awareness in performing CPR. This potential is demonstrated by the fact that all study participants introduced the MOBICPR game to their family members, relatives, or friends, as seen in similar studies where enhanced technology was used teaching adult BLS [53].

This gamified learning approach fits well with the educational theory heutagogy, also known as self-determined learning, where learners determine what they want to learn [8]. In the case of the MOBICPR game, learners can play it at any time to refresh their adult BLS knowledge without waiting for the next training session [54]. Moreover, the use of do-it-yourself manikins made from everyday items, such as plastic bottles, toilet paper, or even a pillow, for practicing CC techniques at home, especially in low-resource settings, coupled with the MOBICPR game, can potentially improve and solidify practical skills in adult BLS [55-58]. The MOBICPR game also includes gamification features, such as avatars, points, and various audio, textual, and graphical feedback. These gamification elements could motivate learners to engage with the game more frequently than they normally would [59]. Future educational tools, such as the MOBICPR game, should align with the 5 key messages outlined in the recent ERC BLS guidelines, ranging from recognizing cardiac arrest to learning the proper techniques for performing CPR [34]. This adherence is crucial for the effective education and retention of adult BLS skills, particularly following adult BLS courses in a home environment.

This study has several limitations. First, because the study participants were only followed for 4 weeks, we were not able to show that the MOBICPR game improved their long-term retention of resuscitation knowledge and skills. Second, the sample size was small due to the lack of interest of participants in participating in the study and because only 1 generation of participants was able to be included at that time. Third, this was a single-faculty study, which limits the generalizability of the results. Fourth, in this study, participants were familiar with smartphone games. It is unclear how effective the MOBICPR game would be in children or older populations. Fifth, because this was a simulation-based study, the performance results may not be generalizable to real-life situations and could not present the impact on patient outcomes. Finaly, the content in the MOBICPR game was developed by researchers based on recent ERC BLS guidelines [34]. In the future, there are plans to introduce the MOBICPR game to the Slovenian National Resuscitation Council, with the goal of securing its certification, a process akin to that followed by the Italian Resuscitation Council for its smartphone-based serious games [60].

The home use of the MOBICPR game shows promise in enhancing the theoretical knowledge of adult BLS. Although there was no significant improvement in performing adult BLS or in retaining the related knowledge and skills, the study yielded important learning objectives for the enhancement of future adult BLS training. Further research is necessary to explore its lasting effects across various demographics and to determine the most effective use of the MOBICPR game in teaching adult BLS.