Lung-ultrasound objective structured assessment of technical skills (LUS-OSAUS): utility in the assessment of lung-ultrasound trained medical undergraduates

Purpose: Recently, some attempts have been made to integrate lung ultrasound (LUS) teaching into medical curricula. However, current education studies of LUS are extremely heterogeneous due to the lack of evidence-based guidelines on LUS education. In particular, the assessment of competencies is poorly standardized and mostly relies on non-validated scales. A new validated tool, the objective structured assessment of lung ultrasound skills (LUS-OSAUS), has the potential to overcome these limitations. Therefore, we adopted the LUS-OSAUS tool to assess the competencies of a group of LUS-trained undergraduates. Existing no prior practical applications of the LUS-OSAUS, our aim was to investigate the practical utility of this tool and its applicability in the evaluation of US-trained medical students. Methods: Eight undergraduates (two males, six females) were enrolled on a voluntary basis to receive a theoretical and practical training in LUS. Once completed their training, each student performed an LUS examination on a different patient hospitalized for respiratory symptoms. The same eight patients were also scanned by a senior resident in emergency medicine for a comparison with students' results. Students and the senior resident were tested by an examiner using the LUS-OSAUS tool. We compared the scores obtained by operators in all areas of competence of the LUS-OSAUS, the total scores, and the time needed to complete the sonographic task. Results: Median students' score in the single items of the scale was significantly lower than the ones obtained by the senior resident (4.0 [3.3-5.0] vs. 5.0 [5.0-5.0]; p < 0.0001). Students scored significantly lower than the senior resident in each item, except for B-line identification, choice of the correct transducer, and suggested focused questions. Median total score was also lower for students compared to the senior resident (70.5 [61.0-74.8] vs. 84.0 [83.5-84.3] (p = 0.0116). Median time required to complete the examination was significantly higher for students (14.1 [12.8-16.1] vs. 4.7 [3.9-5.2] min, p = 0.0117). Conclusions: The LUS-OSAUS tool allowed for a standardized and comprehensive assessment of student's competencies in lung ultrasound, and helped to discriminate their level of expertise from that of a more experienced operator. The scale also specifically tests the theoretical knowledge of trainees, thus making redundant the use of questionnaires designed for this purpose.