Measuring residents' performance of diagnostic reasoning using clinical vignettes: an international collaborative study

目的：比较日本和美国医学生的诊断思维过程。方法：给学生提供三种临床情景，分别对应于冠状动脉疾病的高、低和中等预测概率。从学生（直觉估计）和文献（参考估计）中得出每个场景的测试前和测试后概率的估计。参考估计值与直观估计值之间的差异用于评估测试特征的知识，估计测试前和测试后疾病概率的能力。结果：美国学生112名，日本学生224名。美国和日本的学生都低估了高前测情景的前测和后测概率，尽管估计值接近参考估计值。美国和日本之间没有显著差异。在低测前概率情境下，两组学生均高估了测前概率和测后概率。然而，日本学生与参考估计的偏差更大。结论：美国和日本学生在低或中等预测概率设置下不能排除疾病，主要是因为预测估计疾病概率较差。但是，美国学生的估计比日本学生准确得多。这种诊断思维模式解释了为什么医学生或新手医生最终会重复不必要的检查。在日本的医学教育中，排除疾病的重要性不如不忽视一种可能的疾病的重要性。据推测，这种传统的态度与美国和日本医学生在诊断思维过程上的差异有关。

OBJECTIVE : To compare the diagnostic thinking process of medical students in Japan and US.METHODS : Students were presented with three clinical scenarios corresponding to high, low, and intermediate pre-test probability of coronary artery disease. Estimates of pre-test and post-test probability for each scenario were elicited from the students (intuitive estimates) and from the literature (reference estimates). The difference between the reference estimates and the intuitive estimates was used for assessing knowledge of test characteristics, ability of estimating pre-test and post-test probability of disease.RESULTS : One hundred twelve students in US and 224 in Japan were participated. Both US and Japanese students underestimated pre-test and post-test probability of high pre-test scenario, although the estimates are close to reference estimates. There was no significant difference between US and Japan. In the low pre-test probability scenario, both students overestimated the pre-test and post-test probability. The deviation from reference estimate was, however, greater in Japanese students.CONCLUSIONS : US and Japanese students could not rule out disease in low or intermediate pre-test probability settings, mainly because of poor pre-test estimates of disease probability. But, US students performed significantly accurate estimation than Japanese students. This diagnostic thinking pattern account for why medical students or novice physicians end up repeating unnecessary examinations.In medical education in Japan, ruling out disease has been less emphasized than the importance of not overlooking a possible disease. It is presumed that this traditional attitude is associated with the difference in the diagnostic thinking process between US and Japanese medical students.