Division of Cardiology, Groote Schuur Hospital, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
Department of Medicine, Groote Schuur Hospital, University of Cape Town, Observatory, Cape Town, 7925, South Africa.
BMC Med Educ. 2021 Aug 3;21(1):417. doi: 10.1186/s12909-021-02854-x.
ECGs are often taught without clinical context. However, in the clinical setting, ECGs are rarely interpreted without knowing the clinical presentation. We aimed to determine whether ECG diagnostic accuracy was influenced by knowledge of the clinical context and/or prior clinical exposure to the ECG diagnosis.
Fourth- (junior) and sixth-year (senior) medical students, as well as medical residents were invited to complete two multiple-choice question (MCQ) tests and a survey. Test 1 comprised 25 ECGs without case vignettes. Test 2, completed immediately thereafter, comprised the same 25 ECGs and MCQs, but with case vignettes for each ECG. Subsequently, participants indicated in the survey when last, during prior clinical clerkships, they have seen each of the 25 conditions tested. Eligible participants completed both tests and survey. We estimated that a minimum sample size of 165 participants would provide 80% power to detect a mean difference of 7% in test scores, considering a type 1 error of 5%.
This study comprised 176 participants (67 [38.1%] junior students, 55 [31.3%] senior students, 54 [30.7%] residents). Prior ECG exposure depended on their level of training, i.e., junior students were exposed to 52% of the conditions tested, senior students 63.4% and residents 96.9%. Overall, there was a marginal improvement in ECG diagnostic accuracy when the clinical context was known (Cohen's d = 0.35, p < 0.001). Gains in diagnostic accuracy were more pronounced amongst residents (Cohen's d = 0.59, p < 0.001), than senior (Cohen's d = 0.38, p < 0.001) or junior students (Cohen's d = 0.29, p < 0.001). All participants were more likely to make a correct ECG diagnosis if they reported having seen the condition during prior clinical training, whether they were provided with a case vignette (odds ratio [OR] 1.46, 95% confidence interval [CI] 1.24-1.71) or not (OR 1.58, 95% CI 1.35-1.84).
ECG interpretation using clinical vignettes devoid of real patient experiences does not appear to have as great an impact on ECG diagnostic accuracy as prior clinical exposure. However, exposure to ECGs during clinical training is largely opportunistic and haphazard. ECG training should therefore not rely on experiential learning alone, but instead be supplemented by other formal methods of instruction.
心电图通常在没有临床背景的情况下进行教学。然而，在临床环境中，很少有在不知道临床表现的情况下对心电图进行解释的情况。我们旨在确定心电图诊断准确性是否受到临床背景知识和/或对心电图诊断的先前临床接触的影响。
邀请四年级（初级）和六年级（高级）医学生以及住院医师参加两项多项选择题（MCQ）测试和一项调查。测试 1 包括 25 份没有病例简介的心电图。随后立即进行测试 2，包括相同的 25 份心电图和 MCQ，但每份心电图都有病例简介。之后，参与者在调查中指出他们在之前的临床实习中最后一次看到了测试中 25 种情况中的哪一种。符合条件的参与者完成了两项测试和调查。我们估计，在考虑到 5%的一类错误的情况下，最小样本量为 165 名参与者将提供 80%的能力来检测测试分数的平均差异 7%。
这项研究包括 176 名参与者（67[38.1%]名初级学生、55[31.3%]名高级学生、54[30.7%]名住院医师）。先前的心电图接触取决于他们的培训水平，即初级学生接触到 52%的测试条件，高级学生接触到 63.4%，住院医师接触到 96.9%。总体而言，当知道临床背景时，心电图诊断准确性略有提高（Cohen's d=0.35，p<0.001）。在诊断准确性方面的提高在住院医师中更为明显（Cohen's d=0.59，p<0.001），而不是高级学生（Cohen's d=0.38，p<0.001）或初级学生（Cohen's d=0.29，p<0.001）。如果所有参与者都报告在之前的临床培训中看到过这种情况，无论是提供病例简介（优势比[OR]1.46，95%置信区间[CI]1.24-1.71）还是没有提供病例简介（OR 1.58，95%CI 1.35-1.84），他们更有可能做出正确的心电图诊断。
使用没有真实患者体验的临床病例简介进行心电图解释，对心电图诊断准确性的影响似乎不如先前的临床接触大。然而，在临床培训期间接触心电图主要是偶然和随意的。因此，心电图培训不应仅依赖于经验学习，而应辅以其他正式的教学方法。
