title: The effect of peer-group size on the delivery of feedback in basic life support refresher training: a cluster randomized controlled trial.
abstract: BACKGROUND
  Students are largely providing feedback to one another when instructor facilitates peer feedback rather than teaching in group training. The number of students in a group affect the learning of students in the group training. We aimed to investigate whether a larger group size increases students' test scores on a post-training test with peer feedback facilitated by instructor after video-guided basic life support (BLS) refresher training. Students' one-rescuer adult BLS skills were assessed by a 2-min checklist-based test 1 year after the initial training.
  
  
  METHODS
  A cluster randomized controlled trial was conducted to evaluate the effect of student number in a group on BLS refresher training. Participants included 115 final-year medical students undergoing their emergency medicine clerkship. The median number of students was 8 in the large groups and 4 in the standard group. The primary outcome was to examine group differences in post-training test scores after video-guided BLS training. Secondary outcomes included the feedback time, number of feedback topics, and results of end-of-training evaluation questionnaires.
  
  
  RESULTS
  Scores on the post-training test increased over three consecutive tests with instructor-led peer feedback, but not differ between large and standard groups. The feedback time was longer and number of feedback topics generated by students were higher in standard groups compared to large groups on the first and second tests. The end-of-training questionnaire revealed that the students in large groups preferred the smaller group size compared to their actual group size.
  
  
  CONCLUSIONS
  In this BLS refresher training, the instructor-led group feedback increased the test score after tutorial video-guided BLS learning, irrespective of the group size. A smaller group size allowed more participations in peer feedback.
authors.affiliation: Department of Emergency Medicine, Hallym University Kangdong Sacred Heart Hospital, Seoul, Republic of Korea.
authors.forename: Youngsuk
authors.initials: Y
authors.lastname: Cho
authors.affiliation: Department of Emergency Medicine, Cha University Bundang Medical Center, 59 Yatap-ro, Bundang-gu, Seongnam-si, 463-712, Gyeonggi-do, South Korea. ontheera@gmail.com.
authors.forename: Sangmo
authors.initials: S
authors.lastname: Je
authors.affiliation: Department of Emergency Medicine, Inje University College of Medicine, Busan, Republic of Korea.
authors.forename: Yoo Sang
authors.initials: YS
authors.lastname: Yoon
authors.affiliation: Department of Medical Education, Inje University College of Medicine, Busan, Republic of Korea.
authors.forename: Hye Rin
authors.initials: HR
authors.lastname: Roh
authors.affiliation: Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.|Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Chulho
authors.initials: C
authors.lastname: Chang
authors.affiliation: Department of Emergency Medicine, Hanyang University College of Medicine, Seoul, Republic of Korea.
authors.forename: Hyunggoo
authors.initials: H
authors.lastname: Kang
authors.affiliation: Department of Emergency Medicine, Hanyang University College of Medicine, Seoul, Republic of Korea.
authors.forename: Taeho
authors.initials: T
authors.lastname: Lim
mesh_terms: D016887:Cardiopulmonary Resuscitation / Q000193:education* / Q000592:standards; D002983:Clinical Competence; D003479:Curriculum; D004504:Education, Medical, Undergraduate / Q000379:methods*; D004521:Educational Measurement; D005260:Female; D000068156:Formative Feedback; D006126:Group Processes; D006801:Humans; D008020:Life Support Care; D008297:Male; D008348:Manikins; D010379:Peer Group; D058996:Quality Improvement; D012153:Retention, Psychology; D013337:Students, Medical / Q000523:psychology
keywords: Basic life support; Cardiac arrest; Cardiopulmonary resuscitation; Educational assessment; Feedback; Instructor; Medical education; Training; Undergraduate medical education