Previous studies from our institution demonstrated dramatic improvements identifying cardiac sounds after listening to 400 repetitions of each sound recorded on audio compact disc (CD). This follow-up study investigated if similar results could be obtained using identical content placed on the Internet for student download.
Twenty-four first-year medical students in a traditional curriculum at an urban east coast medical school were randomized to one of two groups. Both groups received instruction on 5 basic cardiac murmurs (AS, AR, MS, MR, Innocent Murmur) and 2 extra heart sounds (S3, S4). Group A was given a one-hour CD with 200 repetitions of the above heart sounds interspersed with didactic material. Group B was given instructions to download an internet-based digital audio file (DAF) containing content identical to Group A. Both groups were instructed to listen to their CDs or DAFs exactly twice. Computer-based testing was used to assess proficiency at identifying 10 heart sounds played in random order before and after educational intervention.
On completion, twenty-three students were available for analysis (12 in Group A, 11 in Group B). Group A improved from a pre-test proficiency score (M ± SD) of 21.7 ± 11.9% to a post-test score of 69.2 ± 22.3% (p<.001). Group B improved from a pre-test proficiency of 20.0 ± 14.8% to a post-test score of 61.8 ± 21.8% (p<.001). Mann-Whitney testing showed no statistical difference between the two groups (p=.534).
Medical students demonstrated dramatic improvement recognizing cardiac sounds after listening to 400 repetitions of each abnormality. Post-test results were similar and significant regardless of whether the student used a CD or DAF downloaded over the Internet.
These results confirm previous studies demonstrating cardiac auscultation is partially a technical skill requiring repetition for mastery. This study shows delivery of content via the Internet is as effective as delivery via CD. Internet-based distribution allows an effective teaching tool to be made available to many students over multiple clinical sites.
T.C. Seto, Astra-Zeneca