Purpose of the study: Quick first aid can save lives. An appropriate method of low-cost mass-training in first aid can be peer education. Our aim was to measure the effectiveness of peer education in primary schools.
Material and methods: Participants (N=481, 10-14 years old children) from three different primary schools were involved in our study between January 2018 and February 2019. Knowledge and skills about treating an unconscious patient were measured. Children in „case-group 1” (C1) were trained by a health care professional (n=46), in „case-group 2” (C2) were trained by peer-instructors (n=323) and in „control-group” (C3) were not trained (n=92). Seventeen peer-instructors were trained by a health care professional to teach their classmates. Training session was 45-min (theory and hands-on training) for C1 and C2. Data collection was made by a self-fill-in questionnaire (theoretical part) and a checklist based on a simulated situation with an unconscious patient (practical part).
Results: Participants in C1 (p<0.001) and C2 (p<0.001) performed higher quality first aid than children in C3. Results of C1 was superior than C2 (p<0.001).  Children trained by boy (p<0.001) and older (p<0.001) peer-instructors scored better in the practical measurement. Participants with prior first aid training scored better in every groups (p<0.001). Children’s self-efficacy in the different groups was the following: 97.8% of C1, 92.6% of C2 and 87% of C3 thought that they could help in a real emergency situation. 
Conclusions: Children trained by peer-instructors could learn the basics of the treatment of an unconscious patient and their knowledge was superior than the control group. However, children trained by a health care professional scored better in the theoretical and practical measurements than the peer-led group. Participation in a first aid training improved self-efficacy.

3 - Peer-education in primary schools – Is it an effective way of mass first aid training?