Ark Tavinder K, Brooks Lee R, Eva Kevin W
Program for Educational Research and Development, MDCL 3522, McMaster University, 1200 Main Street West, Hamilton, Ontario, Canada, L8N 3Z5.
Acad Med. 2006 Apr;81(4):405-9. doi: 10.1097/00001888-200604000-00017.
There has been much debate in the medical education literature regarding the extent to which feature-driven and nonanalytic (similarity-based) reasoning strategies define expertise, but the relative value of teaching these strategies, together or in isolation, remains uncertain. The purpose of this study was to compare the diagnostic accuracy achieved upon receiving instruction to use each strategy in isolation to that of a combined approach.
In 2003-04, 48 undergraduate psychology students from McMaster University in Ontario, Canada, were taught to diagnose ten cardiac disorders (including normal) via electrocardiogram (ECG) presentation. Twelve students were instructed to carefully identify all features present before assigning a diagnosis (feature first). Twelve were given the same instruction with notice that some test ECGs had been seen during training (implicit combined). Twelve were simply instructed to trust familiarity and diagnose based on this impression (similarity-based). Finally, 12 students were given feature first and similarity-based instructions in combination (explicit combined).
No difference in diagnostic accuracy was observed between the groups given the feature first (42%) and first impression (41%) instructions (p > .4), but the groups instructed to use both strategies (explicitly or implicitly) performed significantly better (56% and 53%, respectively; p < .01).
The results support an additive model of clinical reasoning in which instructions to be feature oriented and to trust similarity improve performance in novice diagnosticians.
医学教育文献中对于特征驱动和非分析性（基于相似性）推理策略在多大程度上界定专业技能存在诸多争论，但单独或综合教授这些策略的相对价值仍不明确。本研究的目的是比较单独接受使用每种策略的指导与综合方法所达到的诊断准确性。
2003 - 2004年，来自加拿大安大略省麦克马斯特大学的48名本科心理学专业学生通过心电图（ECG）展示学习诊断十种心脏疾病（包括正常情况）。12名学生被指导在做出诊断前仔细识别所有呈现的特征（特征优先）。12名学生收到相同指导，并被告知在训练中见过一些测试心电图（隐性综合）。12名学生仅被指导依靠熟悉感并基于此印象进行诊断（基于相似性）。最后，12名学生同时接受特征优先和基于相似性的指导（显性综合）。
接受特征优先（42%）和第一印象（41%）指导的两组在诊断准确性上未观察到差异（p > 0.4），但被指导使用两种策略（显性或隐性）的组表现明显更好（分别为56%和53%；p < 0.01）。
结果支持临床推理的累加模型，即特征导向和依靠相似性的指导可提高新手诊断医生的表现。
