Courses on basic life support (BLS) and automated external defibrillator (AED) in schools lead to increase in knowledge but its retention is less well explored. We aimed to explore the long-term retention of knowledge and practical skills among schoolchildren after a BLS and AED course to be able to tailor future courses accordingly. Study was conducted in 3 parts and included 823 seventh and ninth graders from different elementary schools in Maribor, Slovenia. In Study 1 (n=611) we assessed students' baseline knowledge and immediate knowledge gain after our BLS and AED course with a validated questionnaire; in Study 2 (n=116) we assessed retention of gained knowledge and skills after 5 months with a modified Cardiff test and Little Anne QCPR manikin; in Study 3 (n=96) we assessed retention of knowledge 2 years after the course. Mean differences in knowledge before and after the course in Study 1 and between studies were analyzed using paired t-tests and independent t-tests. Differences between individual question scores at different time points were compared using Mann - Whitney U test. A two-sided P<0,05 was considered significant. Practical skills retention was presented with descriptive statistics. Knowledge gain was significant immediately after the course with 83% correct answers compared to 60% at baseline. Scores dropped significantly after 5 months (73%) and after 2 years (75%), but remained significantly better than at baseline (P<0.001). Practical skills perfomance score as per Cardiff test after 5 months was 63%. Overall BLS performance score as per QCPR app was 59%, with an overall cardio score of 77% (average compression rate: 124/min and depth: 52 mm) and ventilation score of 44%. This study showed that long term retention of theoretical knowledge was satisfying whereas poor practical skills performance after 5 months calls for a more intense practical training on repeat courses.
Keywords: automated external defibrillator; cardiopulmonary resuscitation; knowledge; out-of-hospital cardiac arrest; schoolchildren; teaching.