Student Tutors Are Able to Teach Basic

Original Article

Student Tutors Are Able to Teach Basic Sonographic Anatomy Effectively – a Prospective Randomized Controlled Trial Studentische Tutoren können Grundlagen der Ultraschallanatomie des Oberbauchs effektiv unterrichten: eine prospektive, randomisierte, kontrollierte Studie Authors

N. Celebi1, K. Zwirner2, U. Lischner2, M. Bauder2, K. Ditthard2, S. Schürger2, R. Riessen3, C. Engel4, B. Balletshofer1, P. Weyrich1

Affiliations

1

3 4

Key words

▶ abdomen ● ▶ head/neck ● ▶ education ●

received accepted

21.4.2010 18.9.2010

Bibliography DOI http://dx.doi.org/10.1055/ s-0029-1245837 Published online 2010 Ultraschall in Med © Georg Thieme Verlag KG Stuttgart ∙ New York ∙ ISSN 0172-4614 Correspondence Dr. Nora Celebi University of Tuebingen, Department Internal Medicine IV Otfried-Müller-Str. 10 72076 Tübingen Germany Tel.: ++ 49/70 71/2 98 27 11 Fax: ++ 49/74 72/92 56 44 [email protected]

University of Tuebingen, Department Internal Medicine IV University of Tuebingen Medical Intensive Care Unit, University Hospital of Tuebingen Institute for Medical Biometry, Tuebingen

Zusammenfassung

Abstract

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Ziel: Ultraschall ist eine verbreitete diagnostische Methode. Im Medizinstudium können z. B. Ultraschall-Anatomie und grundlegende Ultraschalldiagnostik unterrichtet werden. Einige medizinische Fakultäten haben Ultraschallkurse mit studentischen Tutoren implementiert, um der wachsenden Nachfrage an Ultraschallausbildung gerecht zu werden. Obwohl dieses Unterrichtskonzept als praktikabel und gut akzeptiert gilt, gibt es kaum Daten, die die Effektivität dieser Kurse belegen. Wir haben daher untersucht, ob studentische Tutoren grundlegende Ultraschallanatomie genauso effektiv unterrichten können wie Ultraschall-erfahrene Ärzte. Material und Methoden: 50 Medizinstudenten wurden in zwei Gruppen randomisiert. 46 Datensätze konnten ausgewertet werden. Eine Gruppe wurde von studentischen Tutoren (ST), die andere von einem Ultraschall-erfahrenen Arzt (UA) unterrichtet. In einem Prä-/Post-Design mussten die Studenten 15 anatomische Strukturen darstellen. Dazu durften sie in 3 min maximal drei Bilder anfertigen, anschließend beschrifteten sie die Strukturen, die sie erkannten. Die Bilder wurden von 2 verblindeten Ultraschall-erfahrenen Ärzten ausgewertet. Eine Abweichung von maximal einer Struktur in der Verbesserung zwischen Präund Post-Test der beiden Gruppen wurde als äquivalent angesehen. Ergebnisse: Im Prä-Test identifizierten die ST (UA) 1,6 ± 1,0 (2,0 ± 1,1) Strukturen korrekt. Beide Gruppen verbesserten sich und identifizierten im Post-Test 7,8 ± 2,8 vs. 8,9 ± 2,9 Strukturen (beide p < 0,0001). Im Vergleich waren die Verbesserungen der ST (6,2 ± 2,8 Strukturen) den der UA (6,9 ± 3,2 Strukturen) äquivalent (p < 0,05 im T-Test für Äquivalenz). Schlussfolgerung: Studentische Tutoren können grundlegende Aspekte der Ultraschallanatomie des Oberbauchs vergleichbar effektiv unterrichten wie Ultraschall-erfahrene Ärzte.

Purpose: Ultrasound is a widely used diagnostic tool. In medical education, it can be used to teach sonographic anatomy as well as the basics of ultrasound diagnostics. Some medical schools have begun implementing student tutor-led teaching sessions in sonographic abdominal anatomy in order to meet the growing demand in ultrasound teaching. However, while this teaching concept has proven to be feasible and well accepted, there is limited data regarding its effectiveness. We investigated whether student tutors teach sonographic anatomy as effectively as faculty staff sonographers. Materials and Methods: 50 medical students were randomly assigned to one of two groups. 46 of these could be included in the analysis. One group was taught by student tutors (ST) and the other by a faculty staff sonographer (FS). Using a pre/post-test design, students were required to locate and label 15 different abdominal structures. They printed out three pictures in three minutes and subsequently labeled the structures they were able to identify. The pictures were then rated by two blinded faculty staff sonographers. A mean difference of one point in the improvement of correctly identified abdominal structures between the pre-test and post-test among the two groups was regarded as equivalent. Results: In the pre-test, the ST (FS) correctly identified 1.6 ± 1.0 (2.0 ± 1.1) structures. Both the ST and FS group showed improvement in the posttest, correctly identifying 7.8 ± 2.8 vs. 8.9 ± 2.9 structures, respectively (p < .0001 each). Comparing the improvement of the ST (6.2 ± 2.8 structures) versus the FS (6.9 ± 3.2) showed equivalent results between the two groups (p < .05 testing for equivalence). Conclusion: Basic abdominal sonographic anatomy can be taught effectively by student tutors.

Celebi N et al. Student Tutors Are… Ultraschall in Med

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2

Original Article

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As a cheap and widely available instrument which is free of relevant side effects, ultrasound has become a central diagnostic tool, especially during the evaluation of patients in the emergency room as well as in general medicine [1, 2]. Teaching medical students how to carry out basic ultrasound diagnostics has several benefits, including improving the understanding of clinical and functional anatomy and providing insight into the possibilities and limitations of the diagnostic tool, and is also fun, with forms of “learning by doing” having been shown to be both highly effective and well accepted by medical students [3 – 5]. There is currently a great demand for teaching concepts with proven effectiveness, as reflected by the ever-increasing number of medical education publications [6]. Ultrasound diagnostics are most effectively taught in very small groups in order to allow hands-on experience and individual student-teacher interaction [5, 7]. Becoming an expert sonographer, however, usually takes months or even years of training. Therefore, the number of possible ultrasound teachers from faculty staff is limited [1, 8 – 10]. The aim of an undergraduate ultrasound course is generally not to become an expert sonographer but rather to make the first and essential step in learning how to find and recognize anatomical structures [1]. This can be achieved in a far shorter time period than that required to become a diagnostic expert [3, 11 – 15]. The conditions for reciprocal ultrasound in young medical students are generally perfect: when students examine themselves, they do not have to deal with complex pathologies or with obese or immobile patients. However it is still not clear whether it is necessary to be a professional sonographer to teach undergraduate medical students basic sonographic anatomy. Peer-assisted learning has been shown to be feasible and effective for a variety of skills [16 – 24] and several medical schools have successfully implemented ultrasound teaching sessions held by student tutors [4]. In a very recent study, Knobe et al. were able to show that the test results of students interpreting sonography pictures of musculoskeletal structures in the shoulder were equal when comparing student teacher-led to faculty staff-led teaching [25]. However, the effectiveness of this peer-assisted learning strategy was not investigated in this study since no pre-training analysis was conducted. In addition, the ability to identify key abdominal structures is very useful for medical novices since common severe pathologies that require urgent therapy (e. g. a grossly dilated bile duct, urinary tract obstruction or ascites) can be found even with little training – if the ultrasound novice is able to locate the corresponding anatomical structure in question. In our study, we therefore investigated whether abdominal sonographic anatomy can be effectively taught by student tutors and whether this training yields a comparable learning outcome to that of faculty staff sonographers.

Methods !

Study design 50 medical students without previous structured ultrasound training (2nd to 6th year) were randomly assigned to one of two equally large groups. One group was taught by student tutors (ST) and the other by a faculty staff sonographer (FS).

Celebi N et al. Student Tutors Are… Ultraschall in Med

Both groups were assessed using an identical pre-test and post-test (see the “Assessment” section below).

Ethical issues The application form for the ultrasound tutorial clearly stated that only tutorial participants who also chose to participate in the study would be assessed and that these assessments would be conducted in certain announced lessons. All participating students were thus informed and voluntarily chose to participate in the study. Students who chose not to participate received the same number of extra lessons which were held by student tutors only. Each student provided written consent to be informed in the case of a pathological finding. The study protocol was approved by the local ethics committee.

Student tutor training The student tutor training comprised four parts: ▶ A two-hour propaedeutic seminar (sonographic anatomy, orientation, handling of the ultrasound control panel, artifacts) in small groups of up to four students with practical training on the ultrasound machine. ▶ A three-week full-time clerkship in ultrasound, during which students watched faculty staff sonographers performing ultrasound diagnostics and conducted closely supervised examinations themselves. ▶ A two-hour examination in which the student tutors simulated parts of the teaching sessions and demonstrated to the supervisor how to find and identify the required anatomical structures. ▶ A 12-hour, standardized student tutor didactic seminar [22].

Faculty staff education The faculty staff ultrasound teacher had three years of sonographic experience including a full-time 18-month rotation in internal medicine ultrasound and had attended the standardized German ultrasound course [26] conducted by the DEGUM (Deutsche Gesellschaft für Ultraschall in der Medizin, German Society of Ultrasound in Medicine). The two blinded raters had both completed at least six months of full-time rotation in internal medicine ultrasound and had also attended the standardized German ultrasound course.

Ultrasound lessons The sonographic anatomy teaching module was comprised of four 90-minute lessons: ▶ Ultrasound technique, orientation, artifacts, handling of the ultrasound control panel, Abdominal Anatomy Part 1: pancreas, great abdominal vessels, lymph nodes ▶ Abdominal Anatomy Part 2: liver, gallbladder, bile duct ▶ Abdominal Anatomy Part 3: spleen, kidney, bladder, uterus, prostate ▶ Cervical Anatomy: thyroid, muscles, vessels, lymph nodes Medical students were welcomed and the student tutor and faculty staff sonographer introduced themselves using their first names and without mentioning their qualifications in order to avoid drawing attention to the study setting. In each lesson, five students were taught by either the faculty staff sonographer or one tutor at the same time in different locations and using two identical ultrasound systems (Siemens Sonoline Versa Pro). There was no interaction between the two teaching groups.

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Introduction

Original Article

In the pre-test, the ST correctly identified 1.6 ± 1.0 structures and the FS 2.0 ± 1.1 structures. Both the ST and FS groups showed improvement in the post-test, correctly identifying 7.8 ± 2.8 vs. 8.9 ± 2.9 structures, respectively (p < .0001 for both groups). The improvements (ST 6.2 ± 2.8, FS 6.9 ± 3.2) of both groups were within the defined range with a one-point difference being allowed (p < 0.05).

15

5

0 FS ST pre-test

FS ST post-test

Student Tutors

Fig. 1 Number of located and correctly labeled anatomical structures in the pre-test and post-test in the group taught by student tutors (ST) vs. faculty staff (FS). The student tutors served as a benchmark group. Abb. 1 Dargestellte und korrekt beschriftete Strukturen im Prä- und PostTest der Gruppen, die durch studentische Tutoren (ST) und Ultraschall erfahrene Ärzte (FS) unterrichtet wurden. Die Punktzahl der studentischen Tutoren wurde als Bezugspunkt mit abgebildet.

Table 1

Statistical analysis A difference of less than one structure was considered insignificant. The knowledge gain of the ST and FS was compared with a parametrical t-test and a Wilcoxon test for equivalence. The limit of the difference in improvement between pre-test and post-test for the two groups was set to one point. Due to the normal distribution of the data, a t-test for equivalence according to Wellek, 2003 was used [27]. A subgroup analysis of the difference between the pre-test and post-test in the two training groups was conducted using a paired t-test for difference, after checking for normal distribution of the data. The inter-rater reliabilities were calculated as intraclass correlations and their 95% confidence intervals according to Shrout and Fleiss [28].

Characterics of the study population. ST1

FS2

age (mean ± SD)

25.3 ± 1.8

26.6 ± 5.2

gender male female

11 13

11 11

year (mean ± SD)

3.7 ± 1.0

How often have you previously observed an ultrasound being performed? never once twice more than twice

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1 2

3.8 ± 1.5

0 4 5 15

1 4 3 14

7 8 6 3

11 4 3 4

Have you previously held the position of anatomy tutor? yes no

2 22

5 17

Please rate your anatomic knowledge good moderate bad very bad missing

3 17 2 0 2

5 13 2 1 1

How often have you performed an ultrasound? never once twice more than twice

Results We randomly assigned 50 students to one of the two groups in the present study. A total of four students had to be excluded due to missing data, resulting in 22 students in the faculty staff (FS) group and 24 students in the student tutor (ST) group. The main characteristics that may potentially have influenced ▶ Table 1. ultrasound performance are listed in ●

10

Students taught by student tutors. Students taught by faculty staff.

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We chose an assessment method in which the students had to print a few pictures with many different anatomical structures rather than image every structure multi-plane in order to limit the time needed for the assessment. At the beginning of the pre-test and post-test, the faculty staff sonographer or the student tutor optimized the settings of both the ultrasound machine and the printer and ensured optimal conditions for ultrasound. Before and after the four sonography lessons, the students were asked to locate and label 15 anatomical structures (hepatic artery, upper mesenteric artery, aorta, confluens vena portae, main bile duct, liver, hepatic vein, right renal artery, left renal artery, left renal vein, splenic vein, pancreas, pancreatic duct, portal vein, vena cava). They were allowed to print three pictures in three minutes according to the time required by an ultrasound novice reported by Fernandez-Frackelton [3]. The pictures were attached to a code list comprising the 15 anatomical structures mentioned above. The students subsequently labeled the structures they were able to identify on the picture using the corresponding code. In each group, the two leanest students were selected as sonography models. The printouts were analyzed by two faculty staff sonographers who were blinded to the student group. Each labeled anatomical structure was scored with between 0 and 1 point: ▶ 0 points: structure not found or the indicated structure does not correspond to the label. ▶ 1 /3 point: the indicated structure probably does not correspond to the label. ▶ 2 /3 points: the indicated structure probably corresponds to the label. ▶ 1 point: the indicated structure corresponds to the label. Following course completion, students anonymously rated their ultrasound teachers and the course using a five-point Likert scale.

recognized anatomical structures

Assessment

As a benchmark, the student tutors completed the assessment themselves. According to the ratings of the pictures they printed, the student tutors correctly identified 12.9 ± 1.1 structures ▶ Fig. 1). The inter-rater reliability was 0.83 (95%-CI: 0.72 – (● 0.90) for the pre-test and 0.92 (95%-CI: 0.84 – 0.96) for the post-test. To compare the acceptance of the ultrasound course across groups as well as the performance of student tutors versus the faculty staff sonographer, students anonymously rated both the course and teacher. Both groups rated the course (FS 4.9 ± .3 vs. ST 5.0 ± .0) and their respective teacher (FS 4.9 ± .3 vs. ST 4.8 ±.4) very highly (5-point Likert scale, 1 = very poor, 5 = very good).

Discussion !

Ultrasound is a diagnostic tool which is widely used for a variety of medical education settings such as teaching anatomy under real-time conditions, integrating clinical and basic anatomy, and clinical diagnostic ultrasound. According to our experience, medical students generally ask to be taught how to perform ultrasound examinations. While Hofer et al. demonstrated that a student tutor-led ultrasound course is both feasible and well accepted, there is limited data regarding the effectiveness of such an approach [4]. Only one recent study showed that the examination performance of students taught by student tutors was identical to faculty staff teaching with respect to obtaining and recognizing musculoskeletal structures in ultrasound images of the shoulder [25]. In our investigation, the two study groups showed an equivalent gain in knowledge regarding basic anatomy criteria, indicating that trained student tutors can teach sonographic anatomy as effectively as faculty staff sonographers. For the sake of ease of measurement and to limit the assessment time, we chose recognition of sonographic anatomy as the primary outcome. Students were required to produce printouts within a certain time limit and to label the depicted structures, with student tutors serving as a positive control. We assume that student abilities were underestimated by this methodological approach due to the limited amount of time and printouts allowed. Indeed, even the student tutors failed to achieve full marks, although each tutor proved to be capable of locating and identifying the required structures in the training examination. Our assessment method thus appears to underestimate the student skill level, and the actual knowledge gain might therefore be assumed to be somewhat higher than the present estimates. However, absolute knowledge gain was not the focus of our study. We aimed to compare relative knowledge gain using a standardized, reliable, and valid method. The students were blinded to the research question and since the faculty staff sonographer and the student tutor introduced themselves with their first names only, we assume that the students did not have different perceptions or attitudes regarding the two ultrasound teachers. To rule out different perceptions of the teachers, we asked medical students to rate both the course and their respective teacher. The results confirmed that there were no differences between the groups, with both groups giving high marks to both the teacher and the course. In the study by Knobe et al., the students preferred teaching by faculty staff over student tutor teaching, which is probably due to the relatively short training for the student

Celebi N et al. Student Tutors Are… Ultraschall in Med

tutors (30 minutes of structured training and one week of self-teaching as opposed to 2 × 2 h training sessions, a three week clerkship and a 12-hour didactics seminar in our study) [25]. Peer-assisted learning has been shown to be effective in a variety of settings [16 – 22, 24, 29]. Our study contributes to these findings by showing that peer-assisted learning is also effective in the context of courses in basic ultrasound examination. We demonstrated that student tutors are effective in teaching students the first and essential step in basic ultrasound anatomy: how to locate and recognize key anatomical structures. In addition, this peer-assisted learning model helps the teachers to provide individual feedback to their students, a process that constitutes an indispensable prerequisite for effective skills lab training [30]. We, therefore, are convinced that this learning model provides a feasible, well accepted and effective learning method for faculty-based ultrasound courses in undergraduate medical education. In addition, teaching medical students how to locate key anatomical structures might improve their ability to correctly diagnose and treat emergency patients as young, rather inexperienced doctors, since relevant pathologies e. g. cholestasis, urinary tract obstruction and ascites can be easily recognized with minimal additional training compared to the ultrasound course provided in our study. Further research is required to investigate whether students with basic knowledge in ultrasound diagnostics are able to apply their skills in the daily routine, perform more sonographic examinations with higher quality during clerkships, and transfer their anatomical knowledge to other forms of examination.

Acknowledgment !

The study was supported by a grant provided by the “Tübinger Profil” from the Faculty of Medicine at the University of Tübingen. We thank Ms Dawn Girlich for her excellent help on proof reading.

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