gms | German Medical Science

Introduction: Diagnostic errors are a relevant issue in medical care and can be used to stimulate learning and reflection. A lot of mistakes in daily medical practice are due to difficulties in the clinical reasoning (CR) process. Among the errors relevant in CR it has been shown that experts tend not to consider all relevant information before stating a diagnosis and could thus err due to so called premature closing - the most common cognitive error in CR. There still is a lack of knowledge about the nature of clinical reasoning errors in medical students. Studies on errors in medical students are needed to improve clinical reasoning education. The aim of this study was to analyze the nature and frequency of errors in intermediate medical students.

Methods: Clinical case processing of 88 4th and 5th year Munich medical students was analyzed in a laboratory study. Cases with medical encounter dyspnea were provided in an electronic learning environment (CASUS). Students could freely choose which clinical information to assess in which sequence and for how long to diagnose a case. After each case participants had to state the presumed diagnosis and had to explain why they came to this diagnostic conclusion. To categorize the causes for diagnostic errors, the explanations were analyzed and assigned to an error category based on Graber's coding system of errors [1]. In this system twenty-five cognitive contributions to diagnostic errors are distinguished and grouped into four main categories: faulty knowledge, faulty data gathering, faulty information processing, and faulty verification.

Results: Our study showed that medical students do make diverse diagnostic errors. We observed eight different errors of which the inadequate knowledge base and especially a lack of diagnostic skills were most common (49 and 75 of 307 total errors). Also, problems in collecting all relevant information have been detected. Concentrating on the information processing, faulty context generation (a lack of awareness of relevant aspects) was the most frequent mistake (47 errors) but also premature closing led to many errors (29). The nature of the diagnostic errors differed largely between the cases. Whereas some cases provoked mainly failure in information processing, in other cases participants misdiagnosed especially due to inadequate knowledge and skills.

Conclusion: Although students and experts make diagnostic mistakes caused by the same cognitive mechanisms, their distribution of errors differs largely. Whereas a lack of knowledge does not cause a lot of mistakes in experts, unsurprisingly it is an important cause for errors in students. As well, diagnostic skills of students regarding the interpretation of x-rays, electrocardiograms or lung function tests were poor in our study. Premature closing is also a key issue in students' diagnostic process.