Four-stage teaching technique and chest compression performance of medical students compared to conventional technique

Abstract

Aim: To compare the 2-stage and 4-stage basic life support teaching technique. The second aim was to test if students' self-evaluated knowledge was in accordance with their actual knowledge.

Methods: A total of 126 first-year students of the Faculty of Medicine in Ljubljana were involved in this parallel study conducted in the academic year 2009/2010. They were divided into ten groups. Five groups were taught the 2-stage model and five the 4-stage model. The students were tested in a scenario immediately after the course. Questionnaires were filled in before and after the course. We assessed the absolute values of the chest compression variables and the proportions of students whose performance was evaluated as correct according to our criteria. The results were analyzed with independent samples t test or Mann-Whitney-U test. Proportions were compared with χ(2) test. The correlation was calculated with the Pearson coefficient.

Results: There was no difference between the 2-stage (2S) and the 4-stage approach (4S) in the compression rate (126±13 min-1 vs 124±16 min -1, P=0.180, independent samples t test), compression depth (43±7 mm vs 44±8 mm, P=0.368, independent samples t test), and the number of compressions with correct hand placement (79±32% vs 78±12, P=0.765, Mann-Whitney U-test). However, students from the 4-stage group had a significantly higher average number of compressions per minute (70±13 min -1 2S, 78±12 min-1 4S, P=0.02, independent samples t test). The percentage of students with all the variables correct was the same (13% 2S, 15% 4S, P=0.741, χ2 test). There was no correlation between the students' actual and self-evaluated knowledge (P=0.158, Pearson coefficient=0.127).

Conclusions: The 4-stage teaching technique does not significantly improve the quality of chest compressions. The students' self-evaluation of their performance after the course was too high.

Figure 1

Chart from a study (38) that served as basis for our criteria. In the chart, the x-axis indicates the number of correctly placed compressions and the y-axis indicates the number of volunteers achieving this number.

Figure 2

Self-evaluation of students’ knowledge before and after the course.

Figure 3

Comparison of the self-evaluation and number of correct variables. 0 means that none of the observed variables was correct; 1 means that any one of the following variables was correct: chest compression depth, chest compression rate, or hand placement; 2 means that any two of those variables were correct; and 3 that all of them were correct.