Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT01596465 |
| Other study ID # |
TRHMC-049-010 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
January 2011 |
| Est. completion date |
October 9, 2012 |
Study information
| Verified date |
May 2021 |
| Source |
The Reading Hospital and Medical Center |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Our objective was to test two educational interventions for teaching cardiac auscultation:
self-directed learning using portable audio files versus a single, massed multimedia lecture
intervention similar to current best practice, to determine which would most effectively
increase recognition of common cardiac sounds by physicians. The investigators hypothesized
that doctors learning on their own time could better improve their skills.
Description:
Participants All non-cardiologist physicians were eligible for the study and responded to
recruitment advertising. Participants were 83 non-cardiologist physician volunteers (57
practicing physicians, 26 residents in training) from one Academic Independent Medical Center
in the Northeastern United States enrolled between January 11, 2011 and February 25, 2011.
Participants were randomized by study investigators using a table of random numbers. All
participants were given an MP3 player at the time of enrollment for compensation of their
time, but received no grade for participation. Participants provided their informed consent
before enrolling in the study.
Educational Interventions Following the pretest, participants in the interventional arm of
the study were given an MP3 player which contained eight, 15-second heart sound files (7
pathologic heart sound files and 1 normal heart sound file) alternated with nine leisure
songs. MP3 players could play files in order or "shuffle" files in random order. Each heart
sound file was introduced by the narrated phrase "Identify this sound,", followed by 10 beats
of a heart sound recording, then the narrated identification of the heart sound. Participants
were asked to use the MP3 player in order to improve their auscultation skills as often as
they could and asked to record their activities while listening, but were given no further
training.
Following the pretest, participants in the control arm received a 1-hour multimedia lecture
(Power Point) taught by the same faculty member (AGK), which reviewed the pathophysiology,
exacerbating and relieving factors, as well as visual diagrams of the heart sounds. The
normal and seven pathologic heart sounds were played for participants during the lecture for
a total of 2 minutes through high-quality home stereo speakers, exposing learners to 1280
beats in the 1-hour session. Abnormal sounds were taught in groups of systolic, diastolic and
extra sounds, and were first introduced by name, and then as unknowns using mixed practice in
each of the three sections. At the end of the session, control group participants were given
an MP3 player with no heart sound files as honoraria. Both the intervention and control group
were told they would be retested at 12 weeks. Both were given a paper copy of the Power Point
slides for self-study, but had no electronic access to the original slides. Both groups were
asked not to discuss the study with the other participants.
Content of the audio files The audio files of the heart sounds were obtained from actual
patients and have validity evidence generated in prior studies. The pathologic sounds
included aortic stenosis, aortic insufficiency, mitral stenosis, mitral insufficiency, mitral
valve prolapse, S3, S4, and the normal heart sound. These heart sounds collectively represent
the most important auscultatory findings according to a previously published national survey
of residency program directors.
Measurement All participants took a 15-question pretest in addition to a posttest at 12 weeks
using identical heart sound files to those used in training. Tests consisted of 8-second
clips of each heart sound file, with 10 beats of each sound. Participants were given 15
seconds after each question to choose the correct response from an extended match list that
included 9 choices, one of which was not represented among the training materials ("benign
flow murmur"). Each of the 7 pathologic heart sounds were represented twice, with normal
heart sounds represented once. The order of questions for the test was randomly selected. The
same speakers used in the lecture format were also employed utilized for testing. Study
examiners tested the speaker sound quality before each test. All tests were independently
hand-graded by two graders, and all discrepancies in handwriting and scoring were resolved by
consensus of both investigators. Grades were not shared with participants.
Both groups were asked to rate their prior experience with pathologic heart sounds, including
observation and feedback they have received, satisfaction with the teaching modality and
confidence in their auscultatory skill at the pretest and posttesting. Both groups audited
their preference for learning style by the VARK© learning style assessment instrument Version
7.0, at the time of enrollment. Both groups were asked to record any other methods used to
study auscultation during the study period. Intervention group exposure to heart sounds was
determined by electronic interrogation of their MP3 player at 12 weeks. Play counts recorded
by the device were reviewed by both study investigators and entered on an electronic
spreadsheet.
Data analysis Demographic comparisons, Likert scales of satisfaction and pathologic heart
sound exposure between control and intervention groups were performed via Chi-square testing
and Student's t-test as appropriate. Internal consistency of the pretest was performed using
Cronbach's alpha. Total study time was recorded as 60 minutes for the control group, and was
calculated by the total number of recorded plays multiplied by 15 seconds per play for the
intervention group. Additional self-reported study methods and amount of exposure were
recorded but not added to control and intervention study time calculations. The primary
outcome was the difference in test score from pretest to posttest and was compared using
paired t-tests. Effect sizes for both arms were computed using differences in means divided
by pooled standard deviations. Correlations between exposure and improvement from pretest to
posttest in the intervention group were calculated by linear regression. Subgroup analysis of
intervention group participants who did not use their MP3 player between weeks 4 and 12
(defined as play count= 0 during time interval) was performed to approximate decay in that
group, and was analyzed by paired t-test. The auditory learning preference of the VARK
learning style inventory was characterized dichotomously as present or absent. A two-factor
ANOVA was performed comparing intervention and control groups with presence of auditory
learning style against the primary outcome as the dependent variable to determine the
relative effects of learning style and instructional method. Power calculations were made for
the observed differences between the control and intervention arms for both variables of the
primary objectives.
