Training Thoracic Ultrasound Skills: a Multicentre, Blinded, Randomized Controlled Trial of Simulation-based Training Versus Training on Healthy Figurants
Phase: NA
Conditions: Respiratory Failure, Dyspnea, Pleural Effusion, Pulmonary Edema, Pneumothorax
Sponsor: Odense University Hospital

 
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Training thoracic ultrasound skills: a multicentre, blinded, 
randomized controlled trial of simulation-based training versus 
training on healthy figurants - study protocol. 
 
- A randomized trial in gaining competences in thoracic ultrasound 
 
 
ID number: OP-640 
Version 3.0 
Last updated: October 15th, 2018 
 
Pia Iben Pietersenabc, Ole Graumanncd, Lars Kongee, Søren Helbo Skaarupf, Hans-Henrik Lawaetz 
Schultzg, Christian Borbjerg Laursenac 
 
aDepartment of Respiratory Medicine, Odense University Hospital, bRegional Center for Technical 
Simulation, Odense University Hospital, cInstitute for Clinical Research, University of Southern 
Denmark, dDepartment of Radiology, Odense University Hospital, eCopenhagen Academy of 
Medical Education and Simulation, Capital Region of Denmark,  
 
 
 

 
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Background 
Thoracic ultrasound (TUS) differs from ultrasound examinations in other organ systems, because it 
is not possible in the healthy, ventilated lung to visualize structures or anatomical parts of the lung, 
like it is when examining abdomen or performing an echocardiography [1,2]. It is therefore not 
possible to transfer results directly from educational studies using simulation-based training in other 
areas of medicine, to thoracic ultrasound.  
TUS examinations are considered safe, and without pain, exposure to radiation or delay of patients’ 
course, but ultrasound in general is highly operator dependent [1] and lack of theoretical knowledge 
or practical skills could potentially lead to incorrect diagnosis and thus treatment. Therefor 
simulation-based training, theoretical and practical tests could be the key to a “pre-trained novice” 
with a level of competency higher than a complete novice when performing the first TUS 
examination on a patient in a clinical setting.  
The objective of this trial is to examine whether TUS training on a simulator is superior to training 
on healthy figurants, which today is a commonly used method for gaining skills and competencies 
in TUS. Secondly, to examine whether the choice of hands-on training has an effect on the number 
of examinations performed by the trainees from baseline to 4 months follow-up.  
 
Methods  
The design is a three-armed, multicentre, blinded randomized controlled trial. 
 
Setting 
The trial takes place at three simulation centres at university hospitals in Denmark; Odense 
University Hospital, Rigshospitalet, and Aarhus University Hospital. The intervention period is 
scheduled to run from August 2018 to May 2019.  
 
Participants 
All physicians employed at public hospitals in Region of Southern Denmark, Capital Region of 
Denmark, Region Zealand, and Central Denmark Region, are eligible for inclusion in the trial. 
Because physicians from a wide range of specialities can benefit from TUS examinations, no 
exclusion criteria are established based on the specialities from the physicians.  
The promotion of the educational program and trial is done through posters at the respective 
departments, social media, and educational groups. Trainees sign up for participation, and inclusion 

 
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by mail, and will receive a reply including information about the trial. Exclusion criteria are; lack of 
informed consent, physicians with connection to the trial, or involvement in the design or 
conduction.  
 
Prior to intervention 
Prior to the randomization all participants will complete an online educational programme in TUS 
in order to reach sufficient theoretical knowledge, and must pass a theoretical test and answer a 
questionnaire regarding previous experience with ultrasound in general and TUS, current position 
and employment. All included participants will receive a study identification number that makes it 
possible to pair the results from the questionnaire to the intervention and performances.  
All materials needed prior to the theoretical test, including online educational material, log-in to 
questionnaire and test will be send to the participants by mail as well. The online educational 
material comprises access to Munksgaards’ online portal in basic ultrasound, which includes 
theoretical sonographic sessions, instruction videos in TUS, practical hands-on demonstrations, 
ultrasound clips, and vodcasts. The preparation is estimated to 2-3 hours. The theoretical test is 
administered in Research Electronic Data Capture (REDCap) provided by Odense Patient data 
Explorative Network (OPEN). Participants will be excluded if they do not complete the test. 
 
When participants have completed the test, they will move on to part two, which is the practical 
hands-on training. Part two of the trial will take place in one of the simulation centres. All 
participants will receive an introduction to the ultrasound machine. A medical student working on 
the project will do the introduction, which comprises following general information about 
ultrasound but no information about TUS:  
o Turn on/off 
o Select and change transducer 
o Select preset 
o Adjust depth, gain and focus 
o Store images/clips 
Subsequently, the randomization will take place.  
 
 
 

 
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Randomization 
Randomization is done in REDCap, which allows an online, computer-generated allocation 
sequence concealed to the project leaders. Participants are randomized for hands-on training on 
simulator, healthy figurants, or no intervention, last mentioned serve as controls. The ratio for each 
category is 1:1:1. There is no stratification for site (location).  
 
Trial intervention 
The trial intervention includes a new experimental educational approach; in vitro simulation-based 
TUS training. The TUS module for the US Mentor Simulator is made in collaboration with 3D 
Systems (3D Systems Healthcare, Littleton, USA, formerly known as Simbionix). A TUS expert 
developed nine cases, and the cases cover the most common causes of respiratory failure, dyspnoea 
and cough. The content and curriculum of the educational programme are based on the guidelines 
and recommendations from the Royal College of Radiologists [3], European Federation of Societies 
for Ultrasound in Medicine and Biology [4], International evidence-based recommendations by 
Volpicelli et al. [1], and Lung ultrasound in the critically ill by Lichtenstein et al [5].  
 
This simulation model will serve as first intervention arm, and after the introduction to the 
ultrasound machine, the group randomized for simulation training is allowed to practice for 2.5 
hours before assessment.  
The second intervention arm in the trial is a commonly used hands-on training method; examination 
of healthy volunteers (figurants), in this case medical students who signed up for the job, and who is 
a part of the research group. Trainees are as well allowed to train for up to 2.5 hours, but the 
medical students are not allowed to help or guide the trainee during the examinations.   
Last group will not receive any hands-on training other than the general information, and will serve 
as controls. Figure 1 present a flowchart of the trial. 
  
When trainees have finished the hands-on training, they will continue to assessment of 
competencies, done by an instructor blinded to the intervention. The medical student will inform the 
instructor, and the assessment will take place in the emergency department examining real patients 
suspected to have thoracic pathology/pathologies. As assessment tool the LUS-OSAUS score sheet 
is used [6]. The assessment will be repeated twice.  
 

 
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Blinding 
It is not possible to blind the participants to the educational intervention, but the instructor assessing 
the participants is blinded to the intervention. The data-managers providing the statistical analysis 
are going to be blinded when performing the analyses and when drawing conclusions of the results.  
 
Measurements and assessment of outcomes 
Appendix 1 covers the present codebook (version 1.0, July 2018) of variables, including type of 
variables, legal values and labels. Table 1 provides an overview of the outcomes, and statistical 
analyses, and Table 2 a timeline for obtaining data and registration in the database.  
 
Outcomes 
The primary outcome is difference in LUS-OSAUS score between the three groups [6]. The LUS-
OSAUS score is calculated as the sum of all 17 items in the tool (min. 17, max. 85 point), evaluated 
by instructor and first author, PP. The participant is evaluated two consecutive times.  
The LUS-OSAUS tool is, to our knowledge, the first assessment tool with established evidence of 
validity. The publication shows that LUS-OSAUS can differentiate between different levels of 
competencies.  
Secondary outcome is difference in number of scans performed from baseline to follow-up (4 
months) between the two intervention arms.  
 
Sample size  
Significance 5%, Power 90%, mean difference wanted between the two interventional groups is 8.5 
point. Standard Deviation 8.67. Sample size per group is 22 (total; 66 participants). 
 
Statistical analyses 
Data will be accessed using OPEN analyse, and analysed using STATA and SPSS. OPEN Analyse 
is an analyse environment that complies with the current regulations on data privacy. OPEN 
Analyse acts as terminal server solution from the researcher’s private PC with logging if files, but 
data are stored and processed on a server at the Regional IT.  

 
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A two-sided significance level of 0.05 will be used. Statistical methods for the primary and 
secondary outcomes are presented in Table 1, and include Post Hoc ANOVA with Bonferroni 
correction, hands-on training facility as independent variable (SIM, FIG, controls), and LUS-
OSAUS scores as dependent variable.  
All data will be analysed as intention to treat, therefor missing data will be handled by multiple 
imputation technique, even though missing data are expected to be minimal because instructors are 
registering a great amount of the data to the database.  
 
Ethical considerations 
Participants are physicians, and even though patients are used for assessment, no patient data are 
going to be used. Neither participants nor instructor will look in the electronic patient database, or 
at previous radiological examinations. The patient will be given oral information about the trial 
including aim, running and assessment of participants, and that ultrasound is a non-invasive and 
radiation-free radiological examination with no risk of complications or side effects. Subsequent, 
orally informed consent will be given from the patient. If the ultrasound examination provides 
further information to the patient inquiry, which is suspected as new information, the physician in 
charge of the patient will be informed orally.  
The trial complies with the Declaration of Helsinki on biomedical research and with the act on 
processing personal data. The Regional Committees on Health Research Ethics for Southern 
Denmark has been given the project description and protocol, and found that in accordance to 
Danish regulations, ethical approval is not required for carrying out the trial (S-20172000-44).  
The trial is notified to the Danish Data Protection Agency under the in Region of Southern 
Denmark, and, as prescribed, a data management contract is going to be signed with authors and 
supervisors outside the region. The trial is going to be registered at www.clinicaltrials.gov when the 
account access is available.  
 
The educational programme is planned to include two parts, the web-based theoretical session 
which participants can access at all time, and the hands-on session planned to take place during 
normally working hours. Participants are not going to receive salary or compensation for the 
participation in the educational programme. The educational programme is offered by the 
Simulations Centres in the Regions, and is therefor free of charge for physicians employed at the 
public hospitals. Participants can at any time withdraw from the trial.  

 
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Participants are assured written and orally, that personal data (including questionnaire and 
assessment scores) are anonymized, and will remain this way during data management, storage, 
analyses and reporting or publication.  
 
Discussion 
The presented trial is set to investigate whether a TUS simulator as hands-on training facility, can 
provide a higher level of competencies after 2.5 hour training, than training on healthy figurants, 
which is a commonly used model today [7-9].  
Simulation-based medical education (SBME) has several advantages, and is a complex educational 
intervention that enables both immersive and experimental learning, and makes it possible to 
acquire and maintain skills in a calm and safe environment without putting patients at risk if a 
wrong decision or interpretation is made [10]. The use of this approach has increased within the last 
decade, and in various specialities using technical procedures [11-13].  
Furthermore, all pathologies considered mandatory to the content or course are possible to explore, 
and a trainee is able to practice a particular case or high-risk cases, over and over again, if doubt 
arises or if the trainee does not provide a satisfying result. Seen in a research perspective, SBME 
makes it possible to compare results of different trainees for research purpose, because of a 
standardized set-up. On the other hand, disadvantages in simulation training appear; e.g. if the 
fidelity drops for a short moment, the trainee may use a lot of effort to move back into the 
simulation setting, the technical models require updates, maintenance, and an instructor is often 
necessary in the beginning for introduction, and for emphasizing trainee reflection and peer review 
elements [10]. Last, but not least simulation training cannot replace traditional apprenticeship or 
stand alone, but must be seen as and add-on approach prior to supervised training in a clinical 
setting [10,14].  
 
Today in TUS, it is often a fixed number of examinations on patients that determines whether a 
physician can do a sufficient ultrasound examination sufficiently [3,4,15]. Otherwise a supervisor, 
subjectively, accepts and approves a trainee’s skills, but none of those methods ensure the 
professional level of competencies, and can be affected by external factors and cause feasibility 
problems [16]. There will be situations where a patient is seriously ill, and rapid start of treatment is 
basis for a good outcome. In these situations education is not first priority, and is easily put in line.  

 
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Secondly, due to the varying incidence of various pulmonary diseases and pathologies, hands-on 
training on patients in a clinical setting does not ensure examination of all important sonographic 
findings [17].  
 
To our knowledge no previous studies have been published, comparing the effects of different 
hands-on training facilities in TUS. Several studies have shown a positive effect of one particular 
modality, e.g. laboratory animals [7,18], cadavers [19], phantoms [20], or like in this trial, healthy 
figurants [21] or simulators [22], but did not compare the effects.  
Previous studies that have investigated simulation training in ultrasound of other organ systems than 
lungs or thorax, or ultrasound guided procedures, have showed large and significant effect when 
compared to no training [23,24], but in order to provide realistic and transferable comparison the 
control group should not be no training, but training as is the case today; training on healthy 
figurants. In order to implement simulation training for gaining TUS competencies, and rethink the 
educational tasks for physicians, the results for the simulator group are expected to be better than 
the group of comparison and controls.  
 
Limitations 
The study will suffer from a number of limitations. Given the nature of the trial it is not possible to 
blind the participants, but the instructor assessing the participant is blinded to the intervention. 
During the analyses and reporting, the allocation will be blinded to the data-managers.  
 
TUS is a quit new modality, and the clinical training during follow-up can be influenced by several 
factors as; accessibility of an ultrasound machine in the departments of the participants, 
accessibility of supervision and sparring with other clinicians using lung ultrasound, and attendance 
on courses teaching TUS from baseline to follow-up. To take this into account, participants will fill 
out a questionnaire regarding some of the potential co-factors and confounders, to make it possible 
to stratify for these. Because the trial is randomized we expect these systematic errors and 
confounders to be randomly and equally allocated in the three groups.  
The most optimal primary outcome in educational studies, is a patient-related, clinical outcome, but 
unfortunately this is not possible.  
 
 

 
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Trial status 
Planning of the trial was initiated in March 2017, but validation studies of a written and practical 
test were needed before initiating this trial. The intervention is scheduled to begin in August 2018 
and will continue until April 2019, and follow-up assessments continue until August 2019.  
 
 

 
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Konge L, Lonn L. Simulation-based training of surgical skills. Perspect Med Educ 2016; 
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Havelock T, Teoh R, Laws D et al. Pleural procedures and thoracic ultrasound: British 
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Reznek M HP, Krummel T. Virtual Reality and Simulation: Training the future 
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McGaghie WC, Issenberg SB, Petrusa ER et al. A critical review of simulation-based 
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Sanchez-de-Toledo J, Renter-Valdovinos L, Esteves M et al. Teaching Chest Ultrasound 
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Breitkreutz R, Dutine M, Scheiermann P et al. Thorax, trachea, and lung 
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Completion of online theoretical learning (expected n = XX) 
Do not answer questionnaire  
(n = X) 
Do not complete MCQ-test  
(n = X) 
Do not attend hands-on day 
(n = X)  
Do not complete follow-up 
questionnaire (n = X)  
 
 
 
 
 
 
 
 
 
 
 
Information to all eligible participants: Physicians employed at public hospitals in Region 
of Southern Denmark, Central Denmark Region, Region Zealand, and Capital Region of 
Denmark 
Assessment for eligibility, and acceptance after written information (expected n = XX) 
Pre-study questionnaire, and log-on information to online platform and theoretical test 
Completion of theoretical MCQ-test (expected n = XX) 
Simulation training on 
US Mentor simulator, 
2.5 hour, 9 cases 
available for completion 
(expected n = X)  
Hands-on day (baseline), introduction to ultrasound machine by medical student, and 
randomization (expected n = XX) 
Training on healthy 
figurants, 2.5 hour  
(expected n = X) 
Two times assessment by instructor blinded to the intervention, using LUS-OSAUS 
assessment tool (expected n =X) 
No training 
(expected n = X) 
Follow-up questionnaire, and follow-up analyses (4 months)  
(expected n= X) 
Analyses (expected n = X) 
 
 
Figure 1. Participant flowchart in accordance with the CONSORT statement. 
 
 
 
 
 
 

 
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Table 1. Variables, hypothesis, outcome measures and method of statistical analysis 
 
 
 
Table 2. Timeline of measurements  
 
 
 
 
 
 
 
 
 
 
 
 
 
Hypothesis
Outcone measures Type of variable 
Methods of 
statistical analysis
Primary outcome
Secondary outcome
Difference in LUS-OSAUS between 
the groups
Number of examination performed 
from baseline among the three groups 
to follow up (4 months)
Parametric analysis, 
and ANOVA with 
Bonferroni 
correction for 
multiplicity
Parametric analysis, 
and ANOVA with 
Bonferroni 
correction for 
multiplicity
Gaussian distribution 
expected, continous 
interval data
Gaussian distribution 
expected, continous 
interval data
Sum and percentage 
of maximal number 
of points 
Participant reported 
number of 
examinations 
performed
Training on simulator 
gives the trainee a better 
starting point for doing 
examinations in the 
clinical daily work
Training on simulator 
provides a better result 
than training on healthy 
figurants and no hands-on 
training
Pre study (registration 
and theoretic session)
Baseline (course day) 4 months 
Participant information X
Theoretical Test
X
LUS-OSAUS
XX
Follow-up questionaire
X

 
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Centre Number: 
 
Study Number: 
Participant Identification Number for the trial: 
CONSENT FORM 
Title of Project: Training thoracic ultrasound skills: a multicentre, blinded, randomized controlled trial of 
simulation-based training versus training on healthy figurants  
Name of Researcher: Pia Iben Pietersen 
    Please initial all boxes  
1. I confirm that I have been informed of the study . I have had the opportunity to consider the   
information, ask questions and have had these answered satisfactorily. 
 
 
 
2. I understand that my participation is voluntary and that I am free to withdraw at any time without    
giving any reason, without my medical care or legal rights being affected. 
 
3. I understand that relevant sections of the data may be looked at by individuals from the study group,     
or from regulatory authorities where it is relevant to my taking part in this research. I am informed     
that my data is being kept and handled according to the European Data Protection rules, and I give 
permission for these individuals to have access to my records. 
 
4. I agree to take part in the above study. 
 
 
 
 
 
 
 
Name of Participant ________________________________________________________ 
 
 
 
Date __________________________ Signature _______________________________________________________________ 
                               
 
 
 
Name of Person taking consent ________________________________________________ 
 
 
 
 
Date _________________________ Signature ________________________________________________________________