ABSTRACT
Background: Bone marrow aspiration is an essential but hazardous procedure. We have developed a mannequin simulator with posterior iliac crests to teach needle puncture.<br>Method: After watching a video demonstration of bone marrow aspiration, undergraduate medical students were asked to complete a questionnaire concerning their calmness （C） and self-confidence （S） in performing the procedure using 5-point rating scales （1–5: worst–best） and its estimated ease （E） （1-5: difficult–easy）. The students were given hands-on, small-group instruction using the simulator and allowed to practice, after which they were asked to answer the questionnaire again. The outcome was a change in scores between before and after practice. The paired Student’s t-test （two-tailed） was used for statistical analysis. We also evaluated correlations between pairs among 3 factors.<br>Results: The participants were 200 fifth-year student volunteers from Kawasaki Medical School. The scores after instruction and practice were higher than those before （C: 1.57±0.85 vs. 2.61±1.27; S: 1.61±0.85 vs. 2.86±1.01; and E: 2.36±1.13 vs. 3.65±1.11）. Estimated ease was moderately correlated with self-confidence in performing the procedure after instruction and practice, and the rank-correlation coefficients of before and after were 0.481 and 0.557, respectively. The coefficients of C and E before and after the instruction and practice were 0.346 and 0.526, respectively, whereas the coefficients S and C were 0.487 and 0.414, respectively.<br>Discussion: Simulator-based training may reduce medical students’ anxiety about bone marrow aspiration and its estimated difficulty.