Effectiveness of a video-based refresher on cardiopulmonary resuscitation skill retention in college students: A single-blind randomized controlled trial

ERCT Criteria Breakdown

• Level 1 Criteria

  • C

    Class-level RCT

    • Randomization was at the individual student level within one cohort, not at the class or school level, and the video intervention is not one-to-one tutoring.
    • "Each participant was assigned a unique identification number (1-73), which was entered into the program to generate a computer-produced simple randomization sequence (no stratification or blocking)."
    • Relevant Quotes: 1) "This study was a single-blind randomized controlled trial evaluating 6-month CPR skill retention after initial Basic Life Support (BLS) training among college students." (p. 117) 2) "Participants were randomized 1:1 via a web-based randomizer to either an experimental group, which received a 2-min video refresher at 3 months posttraining, or a control group, which received no refresher." (p. 117) 3) "Each participant was assigned a unique identification number (1-73), which was entered into the program to generate a computer-produced simple randomization sequence (no stratification or blocking)." (p. 118) 4) "In total, 73 students enrolled and underwent BLS training and baseline assessment in small groups of 15-18 to maximize hands-on practice." (p. 117) Detailed Analysis: The C criterion requires randomization at the class level (or the stronger school level), unless the intervention is a personal tutoring / one-to-one teaching design that qualifies for the exception. Here the unit of randomization was clearly the individual student: each of the 73 participants was assigned a personal ID and allocated by a simple computer randomization sequence, not by class or school. All students were drawn from a single 2nd-year cohort at one university and trained in shared small groups, so treatment and control students coexisted in the same environment, creating a plausible contamination risk (e.g., control students could receive the emailed video from treated peers). The intervention is a pre-recorded 2-min self-study video, not interactive one-to-one tutoring, so the personal-teaching exception does not clearly apply. Criterion C is not met because randomization was performed at the individual student level within a single cohort rather than at the class or school level, and the intervention does not qualify for the tutoring exception.
  • E

    Exam-based Assessment

    • Outcomes used a study-derived CPR skills checklist and sensor metrics, not a standardized widely recognized exam.
    • "Secondary outcomes were assessed using a structured checklist derived from KACPR guidelines and organized into three domains with predefined score ranges."
    • Relevant Quotes: 1) "CPR performance was assessed immediately after training (baseline) and at 6 months (follow-up) using a standardized checklist." (p. 117) 2) "Performance was evaluated using (i) a structured checklist and (ii) objective sensor-based metrics captured on an adult Laerdal Little Anne manikin ... retrofitted with the IMLAB CPR Add-on Kit (AoK)." (p. 118) 3) "Secondary outcomes were assessed using a structured checklist derived from KACPR guidelines and organized into three domains with predefined score ranges." (p. 119) 4) "Adequacy thresholds for compression quality followed KDCA-KACPR guidance (e.g. depth >=50 mm [~5 cm], rate 100-120/min, full recoil >= 90%)." (pp. 118-119) Detailed Analysis: The E criterion requires a standardized, widely recognized exam-based assessment that was not specially designed for the study. The outcome here is a practical CPR skills test scored with a structured checklist "derived from KACPR guidelines" plus sensor-based manikin metrics. While the thresholds follow national CPR guidance, the instrument is a study-specific competency checklist and sensor readout, not a standardized, externally validated academic examination with established reliability and norms. This is a bespoke skills assessment, which the standard treats as not satisfying the exam-based requirement. Criterion E is not met because outcomes were measured with a study-derived skills checklist and sensor metrics rather than a standardized, widely recognized exam.
  • T

    Term Duration

    • Outcomes were measured about six months after training, exceeding the one-term tracking requirement.
    • "This study was conducted between October 2023 (training and baseline assessment) and April 2024 (6-month follow-up) among 2nd-year students in the College of Education at a university in Seoul, South Korea."
    • Relevant Quotes: 1) "This study was conducted between October 2023 (training and baseline assessment) and April 2024 (6-month follow-up) among 2nd-year students in the College of Education at a university in Seoul, South Korea." (p. 117) 2) "At 3 months posttraining (January 2024), participants randomized to the intervention arm received a 2-min video refresher via Email and mobile messaging." (p. 118) 3) "Data were collected at two time points: Immediately after the initial BLS training (October 2023) and at 6 months (April 2024)." (p. 118) Detailed Analysis: The T criterion requires outcomes to be measured at least one full academic term (approximately 3-4 months) after the intervention begins, and it explicitly allows naturally short interventions provided follow-up tracking spans at least a term. The initial BLS training began in October 2023 and the outcome was measured in April 2024, an interval of about six months, well beyond one term. Even if the video refresher (January 2024) is taken as the intervention start, the follow-up assessment in April 2024 is about three months later, which meets the minimum term length. The 2-min refresher is a naturally short intervention, but the study tracked retention over a term-length (indeed 6-month) window. Criterion T is met because outcomes were measured approximately six months after initial training (and roughly three months after the refresher), covering at least one full academic term.
  • D

    Documented Control Group

    • The control group's size, demographics, and baseline characteristics are clearly documented in Table 1.
    • "Table 1 summarizes baseline characteristics for the video refresher (n = 33) and control (n = 30) groups ... were similar between groups."
    • Relevant Quotes: 1) "Thus, 63 participants were included in the final analysis (video group n = 33; control n = 30)." (p. 118) 2) "The control group received no refresher." (p. 118) 3) "Table 1 summarizes baseline characteristics for the video refresher (n = 33) and control (n = 30) groups. Age (years, mean +/- SD), sex (n, %), prior CPR experience (n, %), and CPR training within the past 12 months (n, %) were similar between groups." (p. 119) 4) "Table 1: Homogeneity analysis of baseline characteristics ... Control group (n=30) ... Age 20.7+/-1.4 ... Male 13 (43.3), Female 17 (56.7) ... Previous CPR experience No 30 (100) ... CPR training in the last 2 years 3 (10)." (p. 120) Detailed Analysis: The D criterion requires the control group to be well-documented, including demographics, baseline performance, and any treatment received. The paper reports the control group's size (n = 30), age, gender distribution, prior CPR experience, and recent CPR training in Table 1, and explicitly states the control group received no refresher (business as usual). Baseline skill scores were also recorded for all domains at the immediate post-training assessment. This provides clear documentation confirming the control group's characteristics and conditions. Criterion D is met because the control group's size, demographics, baseline characteristics, and lack of refresher are clearly documented in Table 1 and the text.

• Level 2 Criteria

  • S

    School-level RCT

    • Randomization was at the student level within a single institution, so no school-level RCT was conducted.
    • "This single-institution trial in 2nd-year college students (South Korea) limits generalizability to other age groups, settings, or training levels."
    • Relevant Quotes: 1) "Each participant was assigned a unique identification number (1-73), which was entered into the program to generate a computer-produced simple randomization sequence (no stratification or blocking)." (p. 118) 2) "This study was conducted ... among 2nd-year students in the College of Education at a university in Seoul, South Korea." (p. 117) 3) "This single-institution trial in 2nd-year college students (South Korea) limits generalizability to other age groups, settings, or training levels." (p. 122) Detailed Analysis: The S criterion requires randomization at the school (institution/site) level, with multiple schools or units randomized. This trial was conducted at a single university and randomized individual students, not schools or sites. Only one institution was involved, so school-level randomization is impossible by design. Criterion S is not met because randomization occurred at the individual student level within a single institution, not across schools or sites.
  • I

    Independent Conduct

    • The authors designed the intervention and also conducted and analyzed the trial, with no independent evaluator.
    • "Kyeongmin Jang: Conceptualization; Methodology; Investigation; Data curation; Formal analysis ... Supervision."
    • Relevant Quotes: 1) "Kyeongmin Jang: Conceptualization; Methodology; Investigation; Data curation; Formal analysis; Writing - original draft; Writing - review and editing; Supervision." (p. 122) 2) "The script and sequencing reflected the KDCA-KACPR joint guidelines and were reviewed by the study's certified BLS instructors for content accuracy before distribution." (p. 118) 3) "At both time points ... blinded certified instructors conducted checklist assessments using a uniform protocol, while sensor data were captured automatically by the manikin system." (p. 119) 4) "Conflicts of interest: None Declared." (p. 122) Detailed Analysis: The I criterion requires the study to be conducted independently from those who designed the intervention, e.g., by an external evaluation team. Here the same authors conceived, designed, and delivered the intervention (the video refresher was reviewed by the study's own instructors) and also carried out the investigation, data curation, and formal analysis. While outcome assessors were blinded certified instructors, the paper describes them as part of the study team, not an independent third-party evaluator, and there is no statement of external oversight separating the intervention designers from the evaluation. Criterion I is not met because the same team designed the intervention and conducted the trial and analysis, with no independent external evaluator documented.
  • Y

    Year Duration

    • The roughly six-month tracking window is shorter than 75% of an academic year, so the year-duration requirement is not met.
    • "We evaluated whether a brief video-based refresher improves 6-month CPR skill retention."
    • Relevant Quotes: 1) "This study was conducted between October 2023 (training and baseline assessment) and April 2024 (6-month follow-up)." (p. 117) 2) "At 3 months posttraining (January 2024), participants randomized to the intervention arm received a 2-min video refresher." (p. 118) 3) "We evaluated whether a brief video-based refresher improves 6-month CPR skill retention." (p. 116) Detailed Analysis: The Y criterion requires outcome tracking of at least 75% of a full academic year (about 7.5 months of a 9-10 month year) from intervention start. The total tracking window here runs from the October 2023 training to the April 2024 follow-up, about six months; measured from the January 2024 video refresher, it is only about three months. Six months is below the ~75% (roughly 7.5-month) threshold for a full academic year, so the study does not span the required duration. Criterion Y is not met because the tracking window of about six months falls short of the 75%-of-a-year requirement.
  • B

    Balanced Control Group

    • The 2-min video refresher is the explicit treatment variable tested against a business-as-usual control, so the design is balanced.
    • "Participants were randomized 1:1 ... to either an experimental group, which received a 2-min video refresher ... or a control group, which received no refresher."
    • Relevant Quotes: 1) "Participants were randomized 1:1 ... to either an experimental group, which received a 2-min video refresher at 3 months posttraining, or a control group, which received no refresher." (p. 117) 2) "At 3 months posttraining (January 2024), participants randomized to the intervention arm received a 2-min video refresher via Email and mobile messaging ... The control group received no refresher." (p. 118) 3) "This low-cost, scalable strategy may help maintain CPR competence where repeated hands-on training is hard to provide." (p. 116) Detailed Analysis: Criterion B asks whether extra time/budget given to the intervention group is matched in the control group, unless the additional resource is itself the explicit treatment variable. Both arms received the identical initial ~4-hour BLS training; the only additional input to the intervention arm is a single 2-min video refresher delivered asynchronously, while the control group received no refresher. This 2-minute exposure is the explicit treatment variable being tested - the study's entire aim is to evaluate whether adding the brief video refresher improves retention against a business-as-usual (no-refresher) baseline. The extra resource is therefore integral to the research question, and its magnitude (2 minutes) is negligible as a general "time on education" confound. Under the standard's decision logic, the control appropriately represents the business-as-usual comparison. Criterion B is met because the sole added resource, a 2-min video refresher, is the explicit treatment variable tested against a business-as-usual control, and its time cost is negligible.

• Level 3 Criteria

  • R

    Reproduced

    • This is a novel trial with no independent replication of the specific study reported.
    • "However, the effectiveness of brief video refreshers among nonhealthcare college students has not been clearly established."
    • Relevant Quotes: 1) "However, the effectiveness of brief video refreshers among nonhealthcare college students has not been clearly established." (p. 117) 2) "Prior research among nurses has shown video-based CPR self-learning to achieve outcomes comparable to instructor-led formats." (p. 121) 3) "You KM, Shin J, Lee SJ ... Video-enhanced follow-up training improves basic life support skills retention in laypersons: A prospective randomized controlled trial. Hong Kong J Emerg Med 2022." (Reference 10, p. 123) Detailed Analysis: The R criterion requires that this specific study be independently replicated by a different research team in a different context and published in a peer-reviewed journal. This paper is a novel 2026 trial; the authors themselves state the effectiveness of brief video refreshers in this population "has not been clearly established." Related studies exist (e.g., video-based CPR self-learning in nurses, and You et al. 2022 on video-enhanced follow-up training), but these are separate interventions and populations, not independent replications of this specific single-blind trial. A dedicated internet search (Google Scholar, PubMed, and general web) conducted for this verification found no paper by another research team that reproduces this particular Jang and Kim (2026) video-refresher trial; no verbatim replication quotes could be located. Criterion R is not met because there is no independent replication of this specific trial in a peer-reviewed journal.
  • A

    All-subject Exams

    • With criterion E unmet and only CPR skills measured, the all-subject exam requirement is not met.
    • "Secondary outcomes were assessed using a structured checklist derived from KACPR guidelines and organized into three domains."
    • Relevant Quotes: 1) "CPR competencies - cardiac arrest recognition, emergency medical system (EMS) activation, chest compressions, and automated external defibrillator (AED) use - were assessed ... using a standardized checklist." (p. 116) 2) "Secondary outcomes were assessed using a structured checklist derived from KACPR guidelines and organized into three domains." (p. 119) Detailed Analysis: The A criterion requires assessment of all main subjects using standardized exam-based assessments, and it explicitly depends on criterion E being met. E is not met here because the outcome is a study-derived CPR skills checklist rather than a standardized exam. Moreover, the study measures only CPR competency domains, not multiple academic subjects. Criterion A is not met because criterion E is not met and only CPR skills were assessed.
  • G

    Graduation Tracking

    • Tracking stopped at 6 months with no graduation follow-up, and criterion Y is unmet.
    • "Data were collected at two time points: Immediately after the initial BLS training (October 2023) and at 6 months (April 2024)."
    • Relevant Quotes: 1) "We evaluated whether a brief video-based refresher improves 6-month CPR skill retention." (p. 116) 2) "Data were collected at two time points: Immediately after the initial BLS training (October 2023) and at 6 months (April 2024)." (p. 118) 3) "This single-institution trial ... We did not track video-viewing frequency ... the optimal dose/timing of microrefreshers remains uncertain - points to be addressed in larger, multisite trials." (p. 122) Detailed Analysis: The G criterion requires follow-up tracking of participants until graduation and, per the standard, depends on criterion Y being met. Y is not met here. In addition, data collection stopped at the 6-month assessment with no follow-up toward graduation. A dedicated internet search for subsequent tracking publications by the same authors (Jang and Kim) that might follow this cohort to graduation returned no such paper; no verbatim graduation-tracking quotes could be located in any follow-up work. Criterion G is not met because tracking ended at 6 months with no graduation follow-up and criterion Y is not met.
  • P

    Pre-Registered

    • The paper reports IRB approval and CONSORT adherence but no public trial pre-registration ID or date.
    • Relevant Quotes: 1) "We followed the CONSORT guidelines for randomized trials. A CONSORT flow diagram is presented in Figure 2." (p. 119) 2) "This study was approved by the Institutional Review Board of the Seoul Metropolitan Government-Seoul National University Boramae Medical Center (IRB No. 30-2023-85; approval date: June 22, 2023)." (p. 119) 3) "The prespecified primary outcome was chest compression performance at 6 months." (p. 119) Detailed Analysis: The P criterion requires the full study protocol to be pre-registered in a public trial registry (with hypotheses, methods, and analysis plan) before data collection begins. The paper reports IRB ethics approval and adherence to CONSORT reporting, and it references a "prespecified" primary outcome, but it provides no trial registry name, registration ID, or registration date (e.g., ClinicalTrials.gov, ISRCTN, CRIS). A dedicated internet search of the publisher pages and trial registries for this verification found no public pre-registration record for this trial. IRB approval and CONSORT adherence are not equivalent to public pre-registration of the protocol. Criterion P is not met because the paper provides no public trial pre-registration reference or date prior to data collection, and none was found online.