Effectiveness of school-based CPR training among adolescents to enhance knowledge and skills in CPR: A systematic review

Background Cardiac arrest is responsible for 5% – 10% of all deaths among children age 5–19 years; therefore, strategies to prevent poor outcomes post cardiac arrest among children are critical within schools. Objectives The purpose of this study was to systematically review the effectiveness of cardiopulmonary resuscitation (CPR) training on CPR knowledge and skills among adolescent school children. Method This systematic review was conducted and reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. The complete bibliographic databases of PubMed, Cochrane Library, CINAHL and Web of Science were searched from January 2012 to August 2021. Included studies met all the eligibility criteria. The Effective Public Health Practice Project Quality Assessment Tool for Quantitative Studies (EPHPP) and Mixed Method Appraisal tool were used to appraise the quality of the included studies. Results Fourteen studies were included in the review, and 5418 participants were found in the databases. The studies were mainly conducted during the last decade, which suggests that the public’s attention has been directed toward training schoolchildren in CPR. The most common interventions were taught in video simulation training courses. They also used subjective assessments to evaluate the participants’ knowledge and skills. Conclusion Findings from this systematic review reveal that CPR training within school settings effectively promoted a change in CPR knowledge and skills among adolescents. Hence, continuous training of CPR among schoolchildren should be encouraged by policymakers, school authorities, parents and teachers to optimise the prompt usage of the skills in any cardiac event. However, a high-quality randomised controlled trial would enhance the strength of evidence in this area.


Introduction
Out-of-hospital cardiac arrest (OHCA) has remained a significant public health concern. Out-ofhospital cardiac arrest accounts for a substantial number of death worldwide (Pivač, Gradišek & Skela-Savič 2020). Every year, over 700 000 people in Europe and the United States of America suffer from OHCA. The survival rate remains alarmingly low, ranging from 5% to 10% (Wingen et al. 2018). In Australia, an estimated 24 373 cases of OHCA were reported in 2017, with a survival rate of 12% (Pivač et al. 2020). In London, from May 2012 to December 2017, 1055 patients were reported to have OHCA (Reveruzzi, Buckley & Sheehan 2016). These studies prove that OHCA remains the leading healthcare concern worldwide, influencing the morbidity and mortality rates of the population across the world. About 90% of patients who are victims of OHCA die before reaching the hospital; this can be attributed to poor knowledge of cardiopulmonary resuscitation (CPR) (Van Rensburg et al. 2021). According to the Utstein definition, cardiac arrest is a sudden cessation of cardiac mechanical function as evidenced by the absence of detectable pulse, absent or gasping breath and loss of consciousness (Sandroni et al. 2007). external defibrillator use are crucial for saving patients in cardiac arrest. However, the implementation rate for bystander CPR is reported to be low (Xu, Zhang & Chen 2017). Furthermore, resuscitation limits neurological damage caused by cardiac arrest when promptly performed (Chocron et al. 2021). The key strategies to improve survival from OHCA are described as the links in a chain of survival; early recognition of OHCA requires observing signs of poor circulation such as pale face and cold extremities, no breathing and no pulse. The second stage is activating the emergency response by calling the emergency response team for advanced medical assistance, followed by early CPR with chest compressions. Cardiopulmonary resuscitation aims to provide blood circulation to the brain, heart and other vital organs deprived of the circulation caused by cardiac arrest. The last action is rapid defibrillation to rectify the abnormal heart rhythm caused by the cardiac arrest and post-CPR care in the hospital (Chocron et al. 2021). Collectively, these interventions provide the best opportunity to improve OHCA survival.
In OHCA, these critical linked interventions mostly rely on a layperson, who is often the first on the scene (Chocron et al. 2021). However, sporadically when the layperson witnesses the cardiac arrest and commences with the chain of survival links, there is a greater chance that the patient can regain signs of circulation when the emergency response team arrives . Therefore, it would be immensely beneficial if these life-saving skills were introduced at places of employment and learning. Pharaoh, Frantz and Smith (2011) report that life skills are a group of psychosocial competencies and interpersonal skills that help adolescents make informed decisions and deal effectively with the demands and challenges of everyday life. Life skills, according to Hawkins et al. (1999), are a great way to empower adolescents to make educated and responsible decisions about their own lives and well-being, which may be directed toward personal actions. Therefore, introducing CPR training to adolescents who are in school has served as an effective intervention to improve CPR rates and increase survival rates of OHCA (Cave et al. 2011).
Furthermore, early CPR training enhances the safety culture of schools and the role of the teachers to the pupils. For example, should one of the adolescent learners experience cardiac arrest on the soccer field while the teacher is absent, the pupil trained in CPR can save another pupil's life by acting promptly according to the chain of survival links. This can result in long-term structural changes of accountability and confidence in performing in such emergency situations. Furthermore, the pupils trained in CPR can serve as CPR multipliers, as they may pass on the acquired CPR knowledge and skill to family members and friends.
As recommended by the American Heart Association (AHA), the drive for CPR training is a golden opportunity to improve school and community health (Nordheim 2019). Thus, this systematic review aimed to systematically review the effectiveness of CPR training in schools and its impact on CPR knowledge and skills among adolescents.

Study aim
The aim of this study was to systematically review the effectiveness of CPR training in schools and its impact on CPR knowledge and skills among adolescents.

Methods
This systematic review was conducted and reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (Moher et al. 2010). The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) with the reference number CRD42021266518. According to Aromataris and Pearson (2014), a systematic review aims to provide an unbiased synthesis of relevant studies in a single document. A systematic review consists of the inclusion of study selection, critical appraisal and data extraction, which must be conducted by independent reviewers to reduce the risk of error, which may affect the results of the review. The systematic review in the context of this study was regarded as the best choice to employ because it enables the authors to explicitly comprehend the depth of existing knowledge on CPR training, CPR knowledge, CPR skill retention among adolescents and the impact it has on adolescents in schoolbased settings (Aromataris & Pearson 2014).

Search strategy
Independent reviewers B.B. and N.E.Z. searched the databases of PubMed, CINAHL and Cochrane Library to identify studies that were published from January 2012 until August 2021. Medical Subject Headings (MeSH) and free text terms were used in the search to the find studies. For the Web of Science search, a combination of terms and truncation was used. Only human studies that were peer reviewed and published in English were considered. A manual search was also conducted from the references of the studies and other sources to complete the review. See full search strategies in Figure 1.

Study eligibility criteria
Studies were eligible for inclusion if they examined the effects of CPR programs or basic life support (BLS) training (specifically, CPR programs), on CPR knowledge retention, skills, attitudes and perceptions of CPR usage in adolescents between the ages of 12-18 years ( Table 2). To be included in this review, studies had to meet the following eligibility criteria: • Population: generally adolescent schoolchildren aged 12-18 years. • Intervention: interventions or programs which include CPR or BLS. • Outcome: objectively or subjectively measured knowledge of CPR, CPR skills, safety and prevention of cardiac arrest skills, attitude and adolescents' perceptions of CPR usage.
• Design: randomised and nonrandomised trials were included; cross-sectional and qualitative studies, reviews, meta-analyses and guidelines were excluded.

Study selection
All identified articles were exported into EndNote (Clarivate Plc, London, United Kingdom) to remove duplicates and then uploaded onto the Covidence online software (Veritas Health Innovation Ltd, Melbourne, Australia) for screening. The identified articles were initially screened based on titles and abstracts, based on two researchers' eligibility criteria (B.B. and N.E.Z.). Then the same researchers screened the full-text copies of articles that scaled through the title and abstract screening after removing irrelevant articles. A third author (U.U.) resolved potential areas of disagreement on whether to include or exclude articles. Finally, the references of articles identified through database searches were examined to determine any further potentially relevant studies. See complete search strategies in Figure 1.

Quality assessment of studies
The Cochrane Collaboration recommended tool for quantitative studies, Effective Public Health Practice Project Quality Assessment Tool for Quantitative Studies (EPHPP), was used to appraise the quality of the included quantitative studies (EPHPP 2009). In this study, two researchers (B.B. and N.E.Z.) reviewed each study using the EPHPP tool. The tool consists of eight items assessing selection bias, study design, confounders, blinding, data collection methods, withdrawals and dropouts, intervention integrity and analysis. Each item was rated as 1 = strong, 2 = moderate or 3 = weak. For any study that failed to present a clear and transparent description, the item was rated 3 = weak (EPHPP 2009). A 'strong' study connotes studies without weak ratings on any of the eight items. Studies with one weak rating were termed 'moderate', and two or more weak ratings connote 'weak' studies. In the included 14 studies, one used mixed methods. The researchers used the Mixed Method Appraisal Tool (MMAT) to appraise the study. The MMAT is designed to appraise systematic mixed studies reviews and also permits appraisal of the methodological quality of five research categories, namely qualitative, quantitative, randomised control trials (RCTs), nonrandomised, quantitative descriptive and mixed methods studies (Hong 2018). The results of the quality assessment are summarised in Table 1.

Ethical considerations
This article followed all ethical standards for research without direct contact with human or animal subjects.

Results
A total of 143 articles were retrieved from the databases. After the 41 duplicates were removed, 102 were screened for abstract and title, and 81 were excluded. Twenty-one of these were considered for full-text eligibility, and 12 were rejected because they did not meet the eligibility criteria. Fourteen studies (nine RCTs and five non-RCTs) were included in this systematic review. The majority of the studies were of moderate to weak quality.  Kraus et al. (2016), the sub-Saharan African countries have a high prevalance of cardiac arrest with poor clinical outcomes, which are associated with recurrent hospitalisation and a substantial healthcare expenditure. This is in contrast to Western countries, where cardiac arrest affects mostly older persons; in Africa, even adolescents are at risk. The limited literature on school-based CPR intervention in Africa is alarming. In the participating schools, the interventions used to assess the effects of CPR among adolescents in the majority of the studies were mainly instructor-led basic CPR training with video simulations of chest compressions or basic CPR theoretical training. Few studies used virtual reality and video gaming to teach CPR to students (Barsom et al. 2020;Fonseca Del Pozo et al. 2016). The outcome measure used by most of the studies was subjective questionnaires used to assess CPR knowledge and skill. For example, Cortegiani et al. (2017) used Laerdal QCPR 1 software (Laerdal, Stavanger, Norway) to measure chest compressions pre-and post-CPR training. All the included studies had a high risk of bias in the blinding of the participants and assessors. Table 2 details the evidence of synthesis and the characteristics of the included studies.

Effects of interventions on cardiopulmonary resuscitation knowledge and skills
Only one study (Suss-Havemann et al. 2020) out of the 14 included studies reported a lack of significant effect on CPR knowledge and skill retention among adolescents post CPR training. This may be because the study measured self-efficacy in helping students with cardiac arrest and did not directly measure the post-training effect on knowledge of CPR. In resuscitation, self efficacy is defined as the judgement of perceived capability to organise and execute CPR (Roh et al. 2012). According Riggs, Franklin and Saylany (2019), selfefficacy may be associated with improved skills; however, that varies from one population to another. The same authors emphasised that skills detoriate more rapidly than knowledge, and frequent training to effectively ensure self-efficacy is advised, especially among adolescents within the schools (Riggs et al. 2019). In the study by Suss-Havemann et al.
(2020), a nine-point standardised checklist was used to measure self-efficacy using practical skills evaluated during a 3-min scenario testing. This checklist does not explicitly measure the CPR knowledge or skills, but rather it assesses the students' self-efficacy by measuring their readiness to help in three domains: (1) in general, (2) helping in cardiac arrest and (3) diminished emotional arousal to cardiac arrest; the assessment used a four-point Likert scale as follows: 1 = not at all true; 2 = hardly true; 3 = moderately true; 4 = exactly true.

Discussion
This review showed that CPR training within school settings among adolescents effectively enhances adolescents' knowledge, skills and confidence in providing CPR for peers and bystanders with OHCA. The only strong quality RCT in this systematic review demonstrated a lack of selfefficacy scores for helping students with OHCA. This could be because the authors measured self-efficacy in assisting students with cardiac arrest, not participants' CPR knowledge post-training. Previous studies (Pivač et al. 2020;Reveruzzi et al. 2016) had shown that introducing early CPR training among adolescents is essential in enhancing their CPR knowledge, readiness to help others and confidence to provide CPR to peers and bystanders with OHCA.
Western countries have shown that children can learn these basic CPR skills and prevent sudden OHCA. However, findings from this review showed that no country in sub-Saharan Africa had carried out CPR intervention in school settings among adolescents.
Unfortunately, in sub-Saharan Africa, approximately 5 million deaths each year are attributable to conditions that could have been addressed by prehospital care, which is underdeveloped in most low-and middle-income countries, such as cardiac arrest (De Buck et al. 2020). The AHA recommends that CPR training be offered to children in schools starting at 12 years (Weidenauer et al. 2018). The present review indicates that most schools in Africa are yet to key into this rule.
The studies revealed that the training intervention typically targeted adolescents from ages 14 to 18, mainly due to their physical structure and maturity to demonstrate the skill required and retain the theoretical component of the training.
In the 14 studies included in this review, the duration of activity ranged from 50 min to 4 h, including the practical and didactic components. Research by the AHA supports effective CPR training intervention; the longer the duration, the more significant improvement is observed in knowledge and retention of information (Cave et al. 2011).
In this review, the most common interventions used in adolescents' CPR training were instructor-led basic CPR   The studies' predominant tool for outcome measure was questionnaires combined with technical skills assessed by the instructors after the CPR training interventions (Haseneder et al. 2019;Li et al. 2018;Meissner et al. 2012;Wingen et al. 2018). In that way, the researchers could ascertain what steps to perform when witnessing a person with cardiac arrest after the training. Subsequently, the AHA or European Resuscitation Council questionnaire mainly was used to assess the adolescents' CPR knowledge and skills pre-and post-training (Barsom et al. 2020;Nord et al. 2017;Pivač et al. 2020). The assessment included evaluation of scene safety and the consciousness of the victim, calling for emergency assistance, performing chest compressions and airway management. These outcomes influence the adolescents to increase their confidence around CPR, develop their competence and facilitate understanding of the diffusion of responsibility during CPR. Furthermore, the combination of the theory and didactics in training enables them to promptly address the needs of a cardiac arrest victim even though the scenarios they were assessed.
This systematic review revealed vast numbers of CPR schoolbased training interventions offered to adolescents, especially in Western countries. Tsai et al. (2019) followed up with the participants three months post-intervention and found that there was a slight drop of 1% of the participants' CPR knowledge. That was the minimal duration of follow-up in all the included studies. Other follow-up periods of 6 months and 1 year post-intervention showed that overall, the participants' CPR knowledge and CPR technical acquisition remained at a sufficient level. However, it is recommended to have refresher courses more frequently and in shorter intervals for optimal retention of the CPR skills and knowledge (Chien et al. 2020).

Limitations of the study
The major limitation of this review was the lack of any study from the African continent that reported on school-based CPR training among the adolescents, which made it impossible to compare what training intervention strategy works best for resource-limited settings. The other limitation included not having much information that could realistically provide data of the adolescents providing CPR for a real-life scenario post-training.

Implications and future research
Firstly, there should be an urgent and immediate need for CPR training among adolescents in Africa. Secondly, research should focus on the best implementation strategy that would be sustainable in a low-resource setting. Thirdly, high-quality RCTs would be needed to provide evidence-based intervention on the effectiveness of CPR training implemented within school settings to promote change in CPR knowledge, skills and behaviour among adolescents. Lastly, low-and middleincome countries should allocate resources and funds to purchase mannikins and other training materials that would help enhance CPR training among adolescents in schools.

Conclusion
The findings from this study showed that CPR training within school settings effectively promoted a change in CPR knowledge and skills among adolescents. Hence, continuous training of CPR among schoolchildren should be encouraged by policymakers, school authorities, parents and teachers to optimise the prompt usage of the skills in any cardiac event.
http://www.curationis.org.za Open Access review of the manuscript. M.M. was also involved in the software, validation and editing and review of the manuscript. U.U. was involved in the project administartion, methodology, supervision and editing and review of the manuscript.

Funding information
Faculty of Health Care Science dean at North-West University (NWU) provided the authors funding for the CPR manikins and Quality in Nursing and Midwifery (NuMiQ) research focus area for funding the publication fees.

Data availability
The data of this manuscript will be readily available on the North West University repository as soon as it is published.